See the following pages for a complete Table of Contents.
NOTES, CAUTIONS AND WARNINGS
Installer should pay particular attention to the words: NOTE,CAUTION, and WARNING. Notes are intended to clarify ormake the installation easier. Cautions are given to preventequipment damage. Warnings are given to alert installerthat personal injury and/or equipment damage may result ifinstallation procedure is not handled properly.
INSTALLATION MANUAL
CAUTION: READ ALL SAFETY GUIDES BEFORE YOU BEGIN TO INSTALL YOUR UNIT.
TWO-POSITION CONTROL (NONMODULATING POWER EXHAUST) . . . . . . . . . . . . . . 91PROPORTIONAL CONTROL (FAN WITH MODULATING EXHAUST AIR DAMPER (EAD) CONTROLLED FROM
YORK Model Y22/Y23/Y24 units are single package coolingonly or cooling with gas, electric, hot water or steam heatingdesigned for outdoor installation on a rooftop and for non-res-idential use.
The units are completely assembled on rigid, permanentlyattached base rails. All piping, refrigerant charge, and electri-cal wiring is factory installed and tested. The units requireelectric power, gas, steam, or hot water connections and ductconnections. Gas fired units also require installation of a fluegas outlet hood.
SAFETY CONSIDERATIONS
NOTES, CAUTIONS AND WARNINGS
Installer should pay particular attention to the words: NOTE,CAUTION, and WARNING. Notes are intended to clarify ormake the installation easier. Cautions are given to preventequipment damage. Warnings are given to alert installer thatpersonal injury and/or equipment damage may result if instal-lation procedure is not handled properly.
GAS FIRED MODELS
DO NOT store or use gasoline or other flammable vapors andliquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance. Do not touch any electricalswitch. Do not use any phone in your building. Immediatelycall your gas supplier from a neighbor’s phone. Follow thegas supplier’s instructions. If you cannot reach your gas sup-plier, call the fire department.
ALL MODELS
Installation and servicing of air conditioning equipment canbe hazardous due to system pressure and electrical compo-nents. Only trained and qualified service personnel shouldinstall, repair or service air conditioning equipment.
Untrained personnel can perform basic maintenance func-tions of cleaning coils and filters and replacing filters. All otheroperations should be performed by trained service personnel.When working on air conditioning equipment, observe pre-cautions in the literature, tags and labels attached to the unitand other safety precautions that may apply.
Follow all safety codes, including ANSI Z223.1-Latest Edi-tion: wear safety glasses and work gloves; use quenchingcloth for unbrazing operations; have fire extinguisher avail-able for all brazing operations.
INSPECTION
As soon as a unit is received, it should be inspected for possi-ble damage during transit. If damage is evident, the extent ofdamage should be noted on the carrier’s freight bill. A sepa-rate request for inspection by the carrier’s agent should bemade in writing.
The furnace and its individual shut-off valve mustbe disconnected from the gas supply piping sys-tem during any pressure testing of that system attest pressures in excess of 0.5 psig. Pressuresgreater than 0.5 will cause gas valve damageresulting in a hazardous condition. If gas valve issubjected to a pressure greater than 0.5 psig, itmust be replaced. The furnace must be isolatedfrom the gas supply piping system by closing itsindividual manual shut-off valve during any pres-sure testing of that system at test pressures equalto or less than 0.5 psig.
This Furnace is not to be used for temporary heat-ing of buildings or structures under construction.
Before performing service or maintenance opera-tions on unit, turn off main power switch to unit.Electrical shock could cause personal injury.
Improper installation, adjustment, alteration, ser-vice or maintenance can cause injury or propertydamage. Refer to this manual. For assistance oradditional information consult a qualified installer,service agency or the gas supplier.
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REFERENCE
Additional information is available in the following referenceforms:
• 036-21091-004 - Technical Guide• TBD - Unit Replacement Parts List (25, 30 & 40 Tons)
APPROVALS
Designed certified by CGA, ETL, CETL as follows:
1. For use as a forced air furnace with cooling unit (gas heat models).
2. For outdoor installation only.
3. For installation on combustible material and may be installed directly on combustible flooring or Class A, Class B or Class C roof covering materials.
4. For use with natural gas (convertible to LP with kit).
Not suitable for use with conventional venting systems.
INSTALLATION
LIMITATIONS
The installation of this unit must conform to local buildingcodes, or in the absence of local codes, with ANSI Z223.1Natural Fuel Gas Code and /or CAN/CGA B149 installationcodes.
In U.S.A.:
1. National Electrical Code ANSI/NFPA No. 70-Latest Edi-tion.
2. National Fuel Gas Code Z223.1-Latest Edition.
3. Gas-Fired Central Furnace Standard ANSI Z21.47-Lat-est Edition.
4. Local gas utility requirements.
Refer to Table 1 for Cooling and Electrical Application Dataand to Table 2 for Gas Heat Application Data.
After installation, gas fired units must be adjusted to obtain atemperature rise within the range specified on the unit ratingplate.
If components are to be added to a unit to meet local codes,they are to be installed at the contractor's and/or the cus-tomer's expense.
Size of unit for proposed installation should be based on heatloss / heat gain calculation made according to the methods ofthe Air Conditioning Contractors of America (ACCA).
LOCATION
Use the following guidelines to select a suitable location forthese units:
1. Unit is designed for outdoor installation only.
2. Condenser coils must have an unlimited supply of air. Where a choice of location is possible, position the unit on either north or east side of building.
3. Suitable for roof mount on curb.
4. Roof structures must be able to support the weight of the unit and its accessories. Unit must be installed on a solid level roof curb or appropriate angle iron frame.
5. Maintain level tolerance to 3/4 inches across width and 2 inches along length.
Min. Air Temperature on Gas Fired Heat Exchangers (°F)
Aluminized 25 25 25
Stainless 0 0 0
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TABLE 3: GAS APPLICATION DATA
INPUT CAPACITY (MBH)
AVAILABLE ON
MODELS
GAS RATE1
(FT.3/HR.)
TEMP. RISE °FAT FULL INPUT2 30 TO 2,000 FEET ABOVE
SEA LEVEL3,000 FEET ABOVE
SEA LEVEL44,000 FEET ABOVE
SEA LEVEL4
MAX. MIN. MAX. MIN. MAX. MIN. MIN. MAX.
233 233 205 205 196 196 Y22, Y23, Y24 217 5 35
466 233 410 205 392 196 Y22, Y23, Y24 434 15 45
6995 233 615 205 587 196 Y24 650 20 50
1. Based on maximum input and 1075 Btu/Ft.32. The air flow must be adjusted to obtain a temperature rise within the range shown.3. On VAV units, individual room damper boxes must go full open in heating mode to ensure airflow falls within temperature rise
range.4. For operation at elevations above 2,000 feet and, in the absence of specific recommendations from local authority having jurisdic-
tion, equipment ratings shall be reduced at the rate of 4% for each 1,000 feet above sea level.5. Minimum heating CFM for 699 MBH input heat is 11,700 CFM.
If a unit is to be installed on a roof curb other thana YORK roof curb, gasketing must be applied to allsurfaces that come in contact with the unit under-side.
If a unit is to be installed on an angle iron frame itis recommended that it be sized to allow the bot-tom rail to overhang to facilitate installation of con-densate drains (see Fig. 4).
FIGURE 2 - TYPICAL RIGGING
CABLES
SPREADER BARS(3 PLACES)
20"
A
B
C
UNITUNIT
WEIGHT(LB)
LIFTING LUG DIMENSIONS
A B C
25 TON
30 TON
40 TON
SEE NOTE 5
SEE NOTE 5
SEE NOTE 5
8' 4"
8' 4"
8' 4" 6' 9"
6' 9"
6' 9"
2' 3"
2' 3"
2' 3"
RIGGING:
1) RIG WITH 6 CABLES, THREE SPREADER BARS - 95" ACROSS WIDTH AND SPREADER BARS OF LENGTH EQUAL TO "A + B".
2) CENTER OF GRAVITY INCLUDES ECONOMIZER, POWER EXHAUST AND INLET GUIDE VANES.
3) CAUTION: ALL PANELS MUST BE SECURED IN PLACE WHEN THE UNIT IS LIFTED.
4) CAUTION: THE CONDENSER COIL SHOULD BE PROTECTED FROM DAMAGE BY THE RIGGING CABLES WITH PLYWOOD OR OTHER SUITABLE MATERIALS.
5) REFER TO INSTALLATION INSTRUCTIONS.
NOTICE TO RIGGERS
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NOTE: If the Millennium is VAV with ERV, add the weight of an exhaust VFD - it will be in the unit.
.
TABLE 4: UNIT WEIGHTSCOMPONENT 25 TON 30 TON 40 TON
1. Refer to Tables 7 and 8 for A, B, C, D and X and Y data respectively.
All panels must be secured in place when the unit islifted.The condenser coils should be protected from dam-age by the rigging cables with plywood or other suit-able material.An adhesive backed cover is provided over the out-side of the combustion air inlet opening on gas firedunits to prevent moisture from entering the unitwhich could cause damage to electrical compo-nents. Allow this closure label to remain in placeuntil the combustion air hood is to be installed (Referto Figures 7, 8, & 9).
RIGHT SIDE
C�E�N�T�E�R��O�F��G�R�A�V�I�T�Y�
C�O�N�D�E�N�S�E�R�C�O�I�L��E�N�D�
LEFT SIDE
X�
Y�
8�3�"�
2�4�0�"�
A�
B�
C�
D�
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RIGGING AND HANDLING
This unit is not designed to be handled with a fork-truck.
Exercise care when moving the unit. Do not remove anypackaging until the unit is near the place of installation. Rigthe unit by attaching chain or cable slings to the holes pro-vided in lifting lugs. Spreaders MUST be used across the topof the unit. Refer to Figure 2.
• Rig with six cables and spread with four 95-inch spread-ers across width and two spreaders of length equal to A + B.
• Refer to Tables 4 and 7 for unit weight.
• Center of gravity includes economizer, exhaust or return air fan and inlet guide vanes (Refer to Table 8).
NOTES: Basic Unit = cooling only, 10hp FC fan.+ Econ = +235lb+ Heat = single stage gas, 180 lb+ Power Exhaust = modulating 7.5hp
CLEARANCES
All units require certain clearances for proper operation andservice. Installer must make provisions for adequate combus-tion and ventilation air in accordance with section 5.3, Air forCombustion and Ventilation of the National Fuel Gas CodeANSI Z223.1 or Sections 7.2, 7.3 or 7.4 of CAN/CGA B149installation codes-Latest Edition and/or applicable provisionsof the local building codes. Refer to Figure 10 for clearancesrequired for combustible construction, servicing, and properunit operation.
(COOLING OPERATION) Do not permit overhang-ing structures or shrubs to obstruct condenser airdischarge outlet, combustion air inlet or vent out-lets.
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DUCTWORK
Ductwork should be designed and sized according to themethods in Manual Q of the Air Conditioning Contractors ofAmerica (ACCA).
A closed return duct system should be used. This will not pre-clude use of economizers or outdoor fresh air intake. Thesupply and return air duct connections at the unit should bemade with flexible joints to minimize noise.
When the unit is equipped with power exhaust fans or returnair fan the return duct should have a 90 elbow before openingto the building space to abate noise.
The supply and return air duct systems should be designedfor the CFM and static pressure requirements of the job. Theyshould NOT be sized to match the dimensions of the ductconnections on the unit.
If the unit is equipped with hot water or steam heat then thesupply air direction will be down only.
AIR HOODS FOR FIXED OUTSIDE AIR(UNITS WITHOUT ECONOMIZER)
These hoods are factory installed. The dampers may beadjusted by loosening the thumb screw, turning the lever tothe desired position, and retightening the thumb screw.
AIR HOODS FOR ECONOMIZER
There are (3) economizer outside air intake hoods providedwith the unit. The hood on the end of the unit is factorymounted. The (2) front and rear hoods are made operationalper the following instructions.
Remove the screws holding the economizer hood shippingcovers in place. Discard covers.
Rotate the hoods out (each hood is hinged in the lower cor-ner). Secure the hoods with screws along the top and sides.
Apply a bead of RTV sealer along the edge of both hoodsand each pivot joint to prevent water leakage.
Seal any unused screw holes with RTV or by replacing thescrew.
AIR HOODS FOR EXHAUST AIR
When furnished, these hoods and dampers are factoryinstalled.
CONDENSATE DRAIN
There is one condensate drain connection. Trap the connec-tion per Figure 4. The trap and drain lines should be pro-tected from freezing.
Plumbing must conform to local codes. Use a sealing com-pound on male pipe threads. Install condensate drain linesfrom the 1-1/2 inch NPT female connections on the unit to anopen drain.
(GAS HEATING OPERATION)
Excessive exposure to contaminated combustionair will result in safety and performance relatedproblems. To maintain combustion air quality, therecommended source of combustion air is the out-door air supply.
The outdoor air supplied for combustion should befree from contaminants due to chemical exposurethat may be present from the following sources:
• Commercial buildings • Indoor pools • Laundry rooms • Hobby or craft rooms • Chemical storage areas
The following substances should be avoided tomaintain outdoor combustion air quality:
• Permanent wave solutions • Chlorinated waxes and cleaners • Chlorine based swimming pool cleaners • Water softening chemicals • De-icing salts or chemicals • Carbon tetrachloride • Halogen type refrigerants • Cleaning solvents (such as perchloroethylene) • Printing inks, paint removers, varnishes, etc. • Hydrochloric acid • Cements and glues • Antistatic fabric softeners for clothes dryers • Masonry acid washing materials
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SERVICE ACCESS
Access to all serviceable components is provided by the fol-lowing hinged doors:
• Furnace compartment
• Supply Air Fan compartment Evaporator Coil compart-ment (three doors)
Refer to Figure 1 for location of these access panels.
COMPRESSORS
Units are shipped with compressor mountings factory-adjusted and ready for operation.
FILTERS
Throwaway or rigid filters are supplied with each unit. Filtersmust always be installed ahead of evaporator coil and mustbe kept clean or replaced with same size and type. Dirty fil-ters will reduce the capacity of the unit and will result infrosted coils or safety shutdown. Required filter sizes areshown in Table 11. The unit should not be operated withoutfilters properly installed.
THERMOSTAT (CONSTANT VOLUME UNITS)
The thermostat, if used, should be located on an inside wallapproximately 56 inches above the floor where it will not besubject to drafts, sun exposure or heat from electrical fixturesor appliances. Follow manufacturer's instructions enclosedwith sensor for general installation procedure (See Figure 5).Refer to Table 9 for control wire sizing and maximum length.
SPACE SENSOR (VARIABLE AIR VOLUME UNITS)
The space sensor, if used, should be located on an insidewall approximately 56 inch above the floor where it will not besubject to drafts, sun exposure or heat from electrical fixturesor appliances. Follow manufacturer's instructions enclosedwith sensor for general installation procedure.
FIGURE 4 - RECOMMENDED DRAIN PIPING
Make sure that all screws and panel latches arereplaced and properly positioned on the unit tomaintain an air-tight seal.
Field wiring to the unit must conform to provisions of NationalElectrical Code (NEC) ANSI / NFPA 70-Latest Edition and / orlocal ordinances. The unit must be electrically grounded inaccordance with the NEC and / or local codes. Voltage toler-ances which must be maintained at the compressor terminalsduring starting and running conditions are indicated on theunit Rating Plate and Table 1.
The internal wiring harnesses furnished with this unit are anintegral part of the design certified unit. Field alteration tocomply with electrical codes should not be required. If any ofthe wire supplied with the unit must be replaced, replacementwire must be of the type shown on the wiring diagram and thesame minimum gauge as the replaced wire.
Power supply to the unit must be NEC Class 1 and mustcomply with all applicable codes. A disconnect switch mustbe provided (factory option available). The switch must beseparate from all other circuits. Wire entry at knockout open-ings requires conduit fittings to comply with NEC and/or LocalCodes. Refer to Figures 13, 14, 15, and 16 for installationlocation of openings.
If installing a field mounted disconnect on the unit, refer toFigure 17 for the recommended mounting location. Unit-strutTM or equivalent rails should be mounted as shown toprovide structure for mounting. The location of the railsshould be adjusted to fit the disconnect within the dimensionsshown. Conduit run from the disconnect to the power entrylocation in the baserail should be routed so that it does notinterfere with the doors of the unit access panels.
NOTE: Since not all local codes allow the mounting of a dis-connect on the unit, please confirm compliance withlocal code before mounting a disconnect on the unit.
Electrical wiring must be sized properly to carry the load.Each unit must be wired with a separate branch circuit feddirectly from the meter panel and properly fused.
Refer to Figure 5 for typical field wiring and to the appropriateunit wiring diagram mounted inside control doors for controlcircuit and power wiring information.
POWER WIRING DETAIL
Units are factory wired for the voltage shown on the unitnameplate. The main power block requires copper wires.Refer to Electrical Data Tables 13 through 24 to size powerwiring, fuses and disconnect switch. All field supplied wiring,fuses and disconnects must comply with applicable NECcodes.
Power wiring is brought into the unit through the side of thebaserail or the bottom of the unit/control box inside the curb.The baserail has a 2-1/2” diameter hole for field wiring and a3-5/8” hole is provided for a through-the-curb connection. Aremovable patch plate covers both the openings.
ERV
The ERV [Energy Recovery Ventilation] is a separate air han-dler that attaches to the exhaust end of the 25-40T Millen-nium packaged rooftop unit. The ERV is shipped separatelyand assembled to the Millennium at the jobsite. An 'ERV' Mil-lennium is shipped with an end configuration and electrichookups designed to mate with the ERV. This option is avail-able only with the Simplicity control, and no other powerexhaust option can be supplied if an ERV is selected.
The ERV incorporates a rotating heat exchange wheel and apair of exhaust blowers. It exhausts return air through thewheel, capturing the thermal energy of the exiting hot or coldair as it passes. As the wheel rotates, the incoming airstream,pulled through by the supply fan, regains that energy.
The Millennium ERV has a terminal block and mating con-nectors to simplify hooking up the two systems. The controlsof both units are factory set to interact properly. Power for theERV blower motors and controls is provided through the Mil-lennium unit. The Millennium /ERV dataplate informationincludes the ERV electrical load.
The Millennium Simplicity control has parameters for theERV; ref. the parameter list. When economizer and ERVoptions are selected on the same unit, the Simplicity controland the ERV have specific connections and internal rules forthat operation.
Also refer to the ERV Installation Instructions packaged withthe ERV.
Use care to avoid damage when drilling holes forthe disconnect mounting.
When connecting electrical power and control wir-ing to the unit, waterproof connectors MUST BEUSED so that water or moisture cannot be drawninto the unit during normal operation. The abovewaterproofing conditions will also apply wheninstalling a field-supplied disconnect switch.
Waterproof connections MUST be used to ensurethat water cannot penetrate the roof or roof curb.
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GAS HEATING
GAS PIPING
Proper sizing of gas piping depends on the cubic feet perhour of gas flow required, specific gravity of the gas and thelength of run. National Fuel Gas Code Z223.1-Latest Editionshould be followed in all cases unless superseded by localcodes or gas company requirements. Refer to Table 10.
The heating value of the gas may differ with locality. Thevalue should be checked with the local gas utility.
NOTE: There may be a local gas utility requirement specify-ing a minimum diameter for gas piping. All unitsrequire a 1-1/4 inch pipe connection at the entrancefitting. Line should not be sized smaller than theentrance fitting size.
GAS CONNECTION
The gas supply line should be routed within the space andpenetrate the roof at the gas inlet connection of the unit.Refer to Fig. 13 -- 16 to locate the access opening. Typicalsupply piping arrangements are shown in Figure 5.
Gas piping recommendations:
1. A drip leg and a ground joint union must be installed in the gas piping.
2. When required by local codes, a manual shut-off valve will have to be installed outside of the unit.
3. Use wrought iron or steel pipe for all gas lines. Pipe dope should be applied sparingly to male threads only.
4. All piping should be cleaned of dirt and scale by ham-mering on the outside of the pipe and blowing out the loose particles. Before initial start-up, be sure that all of the gas lines external to the unit have been purged of air.
5. The gas supply should be a separate line and installed in accordance with all safety codes as prescribed under Limitations. After the gas connections have been com-pleted, open the main shutoff valve admitting normal gas pressure to the mains. Check all joints for leaks with
On VAV units with gas fired furnace, ALL INDIVID-UAL ROOM DAMPER BOXES MUST BE CON-TROLLED FULL OPEN DURING HEATINGOPERATION TO ENSURE PROPER AIRFLOWOVER THE FURNACE. A control contact betweenD1 and D2 on TB3 is provided for the damper boxinterlock. This contact is normally open, thus isclosed during heating operation.
TABLE 10: PIPE SIZES
LENGTH IN FEET
NOMINAL IRON PIPE, SIZE
1-1/4 IN.1
1. Maximum capacity of pipe in cubic feet of gas per hour (based upon a pressure drop of 0.3 inch water column and 0.6 specific gravity gas.
1-1/2 IN.1 2 IN.1
10 1,050 1,600 3,050
20 730 1,100 2,100
30 590 890 1,650
40 - 760 1,450
50 - - 1,270
60 - - 1,150
70 - - 1,050
80 - - 990
FIGURE 6 - TYPICAL GAS PIPING CONNECTION
Natural gas may contain some propane. Propane,being an excellent solvent, will quickly dissolvewhite lead or most standard commercial com-pounds. Therefore, a special pipe dope must beapplied when wrought iron or steel pipe is used.Shellac base compounds such as Gaskolac orStalastic, and compounds such as Rectorseal #5,Clyde's or John Crane may be used.
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soap solution or other material suitable for the purpose. NEVER USE A FLAME
6. The furnace and its individual manual shut-off valve must be disconnected from the gas supply piping system dur-ing any pressure testing of that system at test pressures in excess of 0.5 psig.
7. A 1/8 inch N.P.T. plugged tapping, accessible for test gage connection, must be installed immediately upstream of the gas supply connection to the furnace.
VENT AND COMBUSTION AIR
NOTE: All the hoods and hardware are shipped within theevaporator section. Each hood must be properlyattached to the furnace doors to assure properoperation and compliance with CSA/ETL safety cer-tification. (Refer to Figure 7 and 8)
The products of combustion are discharged horizontallythrough hooded openings in the gas heat access doors.
233 & 466 MBH HEAT
(Figure 7)
1. Remove the shipping covers that are attached to the heat section door covering the flue outlets.
2. Locate the flue which is shipped in the evaporator sec-tion.
3. Place the flue over the flue outlet with the diverter angles facing up toward the top of the unit and attach with screws provided.
4. Refer to the Gas Furnace Operation Instruction in the Start-up Section of this manual for further instructions.
699 MBH HEAT
(Figure 8)
1. Remove the shipping covers that are attached to the heat section door covering the flue outlets.
2. Locate the flue duct extensions and flue which are shipped between the evaporator and filter section.
Disconnect gas piping from unit when leak testingat pressures greater than 0.5 psig. Pressuresgreater than 0.5 psig will cause gas valve damageresulting in a hazardous condition. If gas valve issubjected to pressure greater than 0.5 psig, it mustbe replaced.
3. Place the flue extension (Figure 9) on the flue duct of each furnace section and attach with screws provided.
4. Place the flue in position with the diverter angles facing up toward the top of the unit and attach with screws pro-vided.
5. Place the wind shield over the louvers on the right side of the burner access door and attach with screws provided.
6. Refer to the Gas Furnace Operation Instructions in the Start-up Section of this manual for further information.
ELECTRIC HEAT
Units with electric heat are fully wired and operational whenshipped. Constant volume units are designed for two equalsteps of capacity for 80 and 108 kWH heat; 40 kW heat is onestep only. VAV units are one full step at full heat capacity.
HOT WATER HEAT
The YORK Millennium units (25, 30, and 40 Ton sizes) can befurnished with a YORK hot water coil as the heat source. Oneor two row coil units will be factory installed in the heatingsection.
NOTE: The hot water control valve will not be provided. Theinstaller will need to purchase a hot water controlvalve, to connect the hot water piping and powerwiring at the job site for the hot water heat section tobe operational.
NOTE: For all hot water coils the entering water tempera-ture should not exceed 200°F.
The hot water coil is located downstream of the supply air fanand just above the supply air opening in the bottom of theunit.
Refer to Tables 58 through 66 and Figures 36 through 49 forflow rate and capacity.
FIGURE 10 - CLEARANCES
60"REAR
60"FRONT
60"ENDS
10'
60"ENDS
REQUIRED CLEARANCES
LEFTRIGHTREARFRONTTOP
60"60"60"60"10'
* Right is the side with access to the Electrical / Gas Controls.* is the side with the Condenser Coils
NOTE: DONOT use the unit roof to support any type ofstructure or bracing.
Front
DO NOT use hot water coils as steam coils underany circumstances.
All piping, control valves, and wiring that is fieldinstalled must be properly insulated and conformto all local and national codes.
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PIPING CONNECTIONS
The hot water pipping must enter the unit through the floor ofthe heat section compartment. The access doors to the com-partment are gasketed so the compartment can be sealed.However, as added protection for water leakage into thespace, the piping access holes should be sealed with a heatresistant mastic Figure 11 shows the location of the compart-ment and piping connections.
STEAM HEAT
The YORK Millennium units (25, 30 and 40 Ton sizes) can befurnished with a YORK single row steam coil. YORK steamcoils are a factory installed option.
There are no provisions in the coil or controlsequence to prevent freezing of condensate. Thecontrol valve, piping and field installed wiring con-nections are particularly vulnerable because theyare installed in the vestibule outside of the condi-tioned air stream. The installing party will beresponsible for properly insulating and installingpower and control wiring, to the actuator and pip-ing.
In one row hot water coil systems DO NOT exceeda 40 gallons per minute flow rate.
In two row hot water coil systems Do Not exceed a80 gallons per minute flow rate
Condensate will freeze on the control valve andpiping if they are not properly insulated. Insulatingthe control valve and piping is the responsibility ofthe installing party.
Piping access holes should be sealed with a heatresistant mastic to prevent damage to equipment.
DO NOT use tin based solder. Brazing with tinbased solder could cause equipment damage orpossible injury to tenets of the structure that isbeing conditioned.
FIGURE 11 - HOT WATER PIPING CROSS-SEC-TION
FIGURE 12 - STEAM PIPING CROSS-SECTION
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NOTE: The steam control valve, power and control wiring tothe actuator of the valve is the responsibility of theinstalling party.
PIPING CONNECTIONS
Refer to Tables 54 through 57 and Figures 50 and 51 for flowrate and capacity.
The steam piping must enter the unit through the floor of theheat section compartment. The access doors to the compart-ment are gasketed so the compartment can be sealed. How-ever, as added protection for condensate leakage into thespace, the piping access holes should be sealed with a heatresistant mastic. The following figure illustrates the location ofthe compartment and piping connections.
STATIC PRESSURE CONTROL PLASTIC TUBING
On units with inlet guide vanes (IGV's) and variable fre-quency drives on the supply blower and/or power exhaustfans, pressure sensing tubing must be field supplied andinstalled from differential pressure switches or transducers tothe locations in the building or ductwork where a constantpressure is desired, and to the atmosphere.
The supply air discharge static pressure switch or transduceris located in the blower compartment on the heat section par-tition panel. Plastic tubing (1/4") must be run from the highpressure tap of the transducer to a static pressure tap (fieldsupplied) in the supply duct located at a point where constantpressure is desired. Tubing must also be run between the lowpressure tap of the transducer to atmospheric pressure.
EXHAUST STATIC PRESSURE
If a modulating power exhaust is installed, there will be abuilding pressure sensor (BPS) in the control box directlybelow the Millennium Simplicity. This ± .25 0-5VDC trans-ducer sends a building pressure signal to the control. A sens-ing tube must be installed from a representative location inthe building to the HI power of the transducer.
Changing the adjustment is done to the building pressureparameter in the control.
All piping and control valves, and wiring that isfield installed must be properly insulated and con-form to all local and national codes.
There are no provisions in the coil or controlsequence to prevent freezing of condensate. Thecontrol valve, piping and field installed wiring con-nections are particularly vulnerable because theyare installed in the vestibule outside of the condi-tioned air stream. The installing party will beresponsible for properly insulating and installingpower and control wiring, to the actuator and pip-ing.
DO NOT use steam coils as hot water coils underany circumstances.
In steam coil systems, the steam pressure shallnot exceed 15 PSI.
Piping access holes should be sealed with a heatresistant mastic to prevent damage to equipment.
DO NOT use tin based solder. Brazing with tinbased solder could cause equipment damage orpossible injury to tenets of the structure that isbeing conditioned.
Do not run plastic tubes in the supply or return airducts as air movement could cause erroneoussensing. If tubes penetrate bottom of unit be sureopenings are sealed against air and water leak-age.
102777-YIM-B-0105
Unitary Products Group 21
TABLE 11: GENERAL PHYSICAL DATA UNIT SIZE 25 TON 30 TON 40 TONUnit EER 10.0 9.5 9.5
Compressor DataNumber/Size 2 x 13 Ton 3 x 10 Ton 4 x 10 Ton
TABLE 19: ELECTRICAL DATA BASIC UNIT WITH POWER EXHAUST - 25 TON
VOLTAGE
SUPPLY AIR MOTOR EXHAUST OR ERV FAN MOTOR(S) BASIC UNIT W/ EXHAUST FAN
HP HP FLA MCA MAX OVERCURRENT PROTECTION DEVICE
208-3-60
7.55 16.7 174 200
7.5 24.2 182 22510 (5 x 2) 30.8 188 225
105 16.7 181 225
7.5 24.2 188 22510 (5 x 2) 30.8 195 225
155 16.7 196 225
7.5 24.2 204 22510 (5 x 2) 30.8 210 250
205 16.7 213 250
7.5 24.2 220 25010 (5 x 2) 30.8 227 250
230-3-60
7.55 15.2 168 200
7.5 22.0 174 20010 (5 x 2) 28.0 180 225
105 15.2 174 200
7.5 22.0 180 22510 (5 x 2) 28.0 186 225
155 15.2 188 225
7.5 22.0 194 22510 (5 x 2) 28.0 200 225
205 15.2 202 250
7.5 22.0 209 25010 (5 x 2) 28.0 215 250
460-3-60
7.55 7.6 87 110
7.5 11.0 91 11010 (5 x 2) 14.0 94 110
105 7.6 90 110
7.5 11.0 94 11010 (5 x 2) 14.0 97 110
155 7.6 97 110
7.5 11.0 101 11010 (5 x 2) 14.0 104 125
205 7.6 104 125
7.5 11.0 107 12510 (5 x 2) 14.0 110 125
575-3-60
7.55 6.1 71 80
7.5 9.0 74 9010 (5 x 2) 11.0 76 90
105 6.1 73 90
7.5 9.0 76 9010 (5 x 2) 11.0 78 90
155 6.1 79 90
7.5 9.0 82 10010 (5 x 2) 11.0 84 100
205 6.1 84 100
7.5 9.0 87 10010 (5 x 2) 11.0 89 110
102777-YIM-B-0105
28 Unitary Products Group
TABLE 20: ELECTRICAL DATA BASIC UNIT WITH POWER EXHAUST - 30 TON
VOLTAGESUPPLY AIR MOTOR EXHAUST OR ERV FAN MOTOR(S) BASIC UNIT WITH EXHAUST FAN
HP HP FLA MCA MAX. OVERCURRENT PROTECTION DEVICE
208-3-60
107.5 24.2 192 225
10 (5 x 2) 30.8 199 22515 (7.5 x 2) 46.2 216 250
157.5 24.2 209 250
10 (5 x 2) 30.8 216 25015 (7.5 x 2) 46.2 231 250
207.5 24.2 226 250
10 (5 x 2) 30.8 233 25015 (7.5 x 2) 46.2 248 300
257.5 24.2 245 300
10 (5 x 2) 30.8 252 30015 (7.5 x 2) 46.2 267 300
230-3-60
107.5 22.0 186 200
10 (5 x 2) 28.0 192 22515 (7.5 x 2) 42.0 207 225
157.5 22.0 201 225
10 (5 x 2) 28.0 207 22515 (7.5 x 2) 42.0 221 250
207.5 22.0 216 250
10 (5 x 2) 28.0 222 25015 (7.5 x 2) 42.0 236 250
257.5 22.0 233 300
10 (5 x 2) 28.0 239 30015 (7.5 x 2) 42.0 253 300
460-3-60
107.5 11.0 92 110
10 (5 x 2) 14.0 95 11015 (7.5 x 2) 21.0 102 110
157.5 11.0 99 110
10 (5 x 2) 14.0 102 11015 (7.5 x 2) 21.0 109 125
207.5 11.0 107 125
10 (5 x 2) 14.0 110 12515 (7.5 x 2) 21.0 117 125
257.5 11.0 115 125
10 (5 x 2) 14.0 118 15015 (7.5 x 2) 21.0 125 150
575-3-60
107.5 9.0 75 90
10 (5 x 2) 11.0 77 9015 (7.5 x 2) 17.0 84 100
157.5 9.0 82 90
10 (5 x 2) 11.0 84 10015 (7.5 x 2) 17.0 90 100
207.5 9.0 88 100
10 (5 x 2) 11.0 90 11015 (7.5 x 2) 17.0 96 110
257.5 9.0 94 110
10 (5 x 2) 11.0 96 11015 (7.5 x 2) 17.0 102 125
102777-YIM-B-0105
Unitary Products Group 29
TABLE 21: ELECTRICAL DATA BASIC UNIT WITH POWER EXHAUST - 40 TON
VOLTAGESUPPLY AIR MOTOR EXHAUST OR ERV FAN MOTOR(S) BASIC UNIT WITH EXHAUST FAN
HP HP FLA MCA MAX. OVERCURRENT PROTECTION DEVICE (MOPD)
208-3-60
107.5 24.2 235 250
10 (5 x 2) 30.8 241 25015 (7.5 x 2) 46.2 259 300
157.5 24.2 252 300
10 (5 x 2) 30.8 259 30015 (7.5 x 2) 46.2 274 300
207.5 24.2 268 300
10 (5 x 2) 30.8 275 30015 (7.5 x 2) 46.2 290 300
257.5 24.2 288 350
10 (5 x 2) 30.8 294 35015 (7.5 x 2) 46.2 310 350
230-3-60
107.5 22 228 250
10 (5 x 2) 28 234 25015 (7.5 x 2) 42 249 250
157.5 22 243 250
10 (5 x 2) 28 249 25015 (7.5 x 2) 42 263 300
207.5 22 258 300
10 (5 x 2) 28 264 30015 (7.5 x 2) 42 278 300
257.5 22 275 300
10 (5 x 2) 28 281 30015 (7.5 x 2) 42 295 350
460-3-60
107.5 11 112 125
10 (5 x 2) 14 115 12515 (7.5 x 2) 21 123 125
157.5 11 120 125
10 (5 x 2) 14 123 12515 (7.5 x 2) 21 130 150
207.5 11 127 150
10 (5 x 2) 14 130 15015 (7.5 x 2) 21 137 150
257.5 11 136 150
10 (5 x 2) 14 139 15015 (7.5 x 2) 21 146 175
575-3-60
107.5 9 92 100
10 (5 x 2) 11 94 11015 (7.5 x 2) 17 101 110
157.5 9 99 110
10 (5 x 2) 11 101 11015 (7.5 x 2) 17 107 110
207.5 9 105 125
10 (5 x 2) 11 107 12515 (7.5 x 2) 17 113 125
257.5 9 111 125
10 (5 x 2) 11 113 12515 (7.5 x 2) 17 119 125
102777-YIM-B-0105
30 Unitary Products Group
TABLE 22: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 25 TON
VOLTAGEELECTRIC HEAT SUPPLY AIR
MOTOREXHAUST OR ERV
FAN MOTOR(S) BASIC UNIT W/ EXHAUST FAN
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION DEVICE
208-3-60
40 30
7.55 16.7 174 200
7.5 24.2 182 22510 (5 x 2) 30.8 188 225
105 16.7 181 225
7.5 24.2 188 22510 (5 x 2) 30.8 195 225
155 16.7 196 225
7.5 24.2 204 22510 (5 x 2) 30.8 210 250
205 16.7 213 250
7.5 24.2 220 25010 (5 x 2) 30.8 227 250
80 60.1
7.55 16.7 218 225
7.5 24.2 227 25010 (5 x 2) 30.8 236 250
105 16.7 226 250
7.5 24.2 236 25010 (5 x 2) 30.8 244 250
155 16.7 245 250
7.5 24.2 255 30010 (5 x 2) 30.8 263 300
205 16.7 262 300
7.5 24.2 271 30010 (5 x 2) 30.8 280 300
230-3-60
40 40
7.55 15.2 168 200
7.5 22.0 174 20010 (5 x 2) 28.0 180 225
105 15.2 174 200
7.5 22.0 180 22510 (5 x 2) 28.0 186 225
155 15.2 188 225
7.5 22.0 195 22510 (5 x 2) 28.0 203 225
205 15.2 202 250
7.5 22.0 210 25010 (5 x 2) 28.0 218 250
80 80
7.55 15.2 231 250
7.5 22.0 239 25010 (5 x 2) 28.0 247 250
105 15.2 238 250
7.5 22.0 247 25010 (5 x 2) 28.0 254 300
155 15.2 256 300
7.5 22.0 264 30010 (5 x 2) 28.0 272 300
205 15.2 271 300
7.5 22.0 279 30010 (5 x 2) 28.0 287 300
102777-YIM-B-0105
Unitary Products Group 31
460-3-60
40 30
7.55 7.6 87 110
7.5 11.0 91 11010 (5 x 2) 14.0 94 110
105 7.6 90 110
7.5 11.0 94 11010 (5 x 2) 14.0 97 110
155 7.6 97 110
7.5 11.0 101 11010 (5 x 2) 14.0 104 125
205 7.6 104 125
7.5 11.0 107 12510 (5 x 2) 14.0 110 125
80 80
7.55 7.6 115 125
7.5 11.0 120 12510 (5 x 2) 14.0 123 125
105 7.6 119 125
7.5 11.0 123 12510 (5 x 2) 14.0 127 150
155 7.6 128 150
7.5 11.0 132 15010 (5 x 2) 14.0 136 150
205 7.6 135 150
7.5 11.0 140 15010 (5 x 2) 14.0 143 150
108 108
7.55 7.6 148 175
7.5 11.0 152 17510 (5 x 2) 14.0 156 175
105 7.6 151 175
7.5 11.0 156 17510 (5 x 2) 14.0 159 175
155 7.6 160 175
7.5 11.0 164 17510 (5 x 2) 14.0 168 175
205 7.6 168 175
7.5 11.0 172 17510 (5 x 2) 14.0 176 200
TABLE 22: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 25 TON (Continued)
VOLTAGEELECTRIC HEAT SUPPLY AIR
MOTOREXHAUST OR ERV
FAN MOTOR(S) BASIC UNIT W/ EXHAUST FAN
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION DEVICE
102777-YIM-B-0105
32 Unitary Products Group
575-3-60
40 40
7.55 6.1 71 80
7.5 9.0 74 9010 (5 x 2) 11.0 76 90
105 6.1 73 90
7.5 9.0 76 9010 (5 x 2) 11.0 79 90
155 6.1 79 90
7.5 9.0 83 10010 (5 x 2) 11.0 85 100
205 6.1 85 100
7.5 9.0 89 10010 (5 x 2) 11.0 91 110
80 80
7.55 6.1 99 110
7.5 9.0 103 11010 (5 x 2) 11.0 105 110
105 6.1 102 110
7.5 9.0 105 11010 (5 x 2) 11.0 108 110
155 6.1 109 110
7.5 9.0 113 12510 (5 x 2) 11.0 115 125
205 6.1 115 125
7.5 9.0 119 12510 (5 x 2) 11.0 122 125
108 108
7.55 6.1 127 150
7.5 9.0 131 15010 (5 x 2) 11.0 133 150
105 6.1 130 150
7.5 9.0 133 15010 (5 x 2) 11.0 136 150
155 6.1 137 150
7.5 9.0 141 15010 (5 x 2) 11.0 143 150
205 6.1 144 150
7.5 9.0 147 15010 (5 x 2) 11.0 150 175
TABLE 22: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 25 TON (Continued)
VOLTAGEELECTRIC HEAT SUPPLY AIR
MOTOREXHAUST OR ERV
FAN MOTOR(S) BASIC UNIT W/ EXHAUST FAN
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION DEVICE
102777-YIM-B-0105
Unitary Products Group 33
TABLE 23: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 30 TON
VOLTAGEELECTRIC HEAT SUPPLY
AIR MOTOREXHAUST OR ERV FAN
MOTOR(S)BASIC UNIT WITH EXHAUST FAN
AND ELECTRIC HEAT
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION
208-3-60
40 30
107.5 24.2 192 225
10 (5 x 2) 30.8 199 22515(7.5 x 2) 46.2 216 250
157.5 24.2 209 250
10 (5 x 2) 30.8 216 25015(7.5 x 2) 46.2 231 250
207.5 24.2 226 250
10 (5 x 2) 30.8 233 25015(7.5 x 2) 46.2 248 300
257.5 24.2 245 300
10 (5 x 2) 30.8 252 30015(7.5 x 2) 46.2 267 300
80 60.1
107.5 24.2 236 250
10 (5 x 2) 30.8 244 25015(7.5 x 2) 46.2 263 300
157.5 24.2 255 300
10 (5 x 2) 30.8 263 30015(7.5 x 2) 46.2 282 300
207.5 24.2 271 300
10 (5 x 2) 30.8 280 30015(7.5 x 2) 46.2 299 300
257.5 24.2 291 350
10 (5 x 2) 30.8 299 35015(7.5 x 2) 46.2 318 350
230-3-60
40 40
107.5 22 186 200
10 (5 x 2) 28 192 22515(7.5 x 2) 42 208 225
157.5 22 201 225
10 (5 x 2) 28 208 22515(7.5 x 2) 42 225 250
207.5 22 216 250
10 (5 x 2) 28 223 25015(7.5 x 2) 42 240 250
257.5 22 233 300
10 (5 x 2) 28 240 30015(7.5 x 2) 42 258 300
80 80
107.5 22 255 300
10 (5 x 2) 28 262 30015(7.5 x 2) 42 280 300
157.5 22 272 300
10 (5 x 2) 28 280 30015(7.5 x 2) 42 297 300
207.5 22 287 300
10 (5 x 2) 28 295 30015(7.5 x 2) 42 312 350
257.5 22 305 350
10 (5 x 2) 28 312 35015(7.5 x 2) 42 330 350
102777-YIM-B-0105
34 Unitary Products Group
460-3-60
40 40
107.5 11 92 110
10 (5 x 2) 14 95 11015(7.5 x 2) 21 104 110
157.5 11 100 110
10 (5 x 2) 14 104 11015(7.5 x 2) 21 113 125
207.5 11 108 125
10 (5 x 2) 14 111 12515(7.5 x 2) 21 120 125
257.5 11 116 125
10 (5 x 2) 14 120 15015(7.5 x 2) 21 129 150
80 80
107.5 11 127 150
10 (5 x 2) 14 131 15015(7.5 x 2) 21 140 150
157.5 11 136 150
10 (5 x 2) 14 140 15015(7.5 x 2) 21 149 150
207.5 11 144 150
10 (5 x 2) 14 147 15015(7.5 x 2) 21 156 175
257.5 11 152 175
10 (5 x 2) 14 156 17515(7.5 x 2) 21 165 175
108 108
107.5 11 161 175
10 (5 x 2) 14 165 17515(7.5 x 2) 21 174 175
157.5 11 170 175
10 (5 x 2) 14 174 17515(7.5 x 2) 21 182 200
207.5 11 177 200
10 (5 x 2) 14 181 20015(7.5 x 2) 21 190 200
257.5 11 186 200
10 (5 x 2) 14 190 20015(7.5 x 2) 21 199 225
TABLE 23: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 30 TON (Continued)
VOLTAGEELECTRIC HEAT SUPPLY
AIR MOTOREXHAUST OR ERV FAN
MOTOR(S)BASIC UNIT WITH EXHAUST FAN
AND ELECTRIC HEAT
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION
102777-YIM-B-0105
Unitary Products Group 35
575-3-60
40 40
107.5 9 75 90
10 (5 x 2) 11 78 9015(7.5 x 2) 17 85 100
157.5 9 83 90
10 (5 x 2) 11 85 10015(7.5 x 2) 17 93 100
207.5 9 89 100
10 (5 x 2) 11 91 11015(7.5 x 2) 17 99 110
257.5 9 95 110
10 (5 x 2) 11 98 11015(7.5 x 2) 17 105 125
80 80
107.5 9 105 110
10 (5 x 2) 11 108 11015(7.5 x 2) 17 115 125
157.5 9 113 125
10 (5 x 2) 11 115 12515(7.5 x 2) 17 123 125
207.5 9 119 125
10 (5 x 2) 11 122 12515(7.5 x 2) 17 129 150
257.5 9 125 150
10 (5 x 2) 11 128 15015(7.5 x 2) 17 135 150
108 108
107.5 9 133 150
10 (5 x 2) 11 136 15015(7.5 x 2) 17 143 150
157.5 9 141 150
10 (5 x 2) 11 143 15015(7.5 x 2) 17 151 175
207.5 9 147 150
10 (5 x 2) 11 150 15015(7.5 x 2) 17 157 175
257.5 9 153 175
10 (5 x 2) 11 156 17515(7.5 x 2) 17 163 175
TABLE 23: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 30 TON (Continued)
VOLTAGEELECTRIC HEAT SUPPLY
AIR MOTOREXHAUST OR ERV FAN
MOTOR(S)BASIC UNIT WITH EXHAUST FAN
AND ELECTRIC HEAT
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION
102777-YIM-B-0105
36 Unitary Products Group
TABLE 24: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 40 TON
VOLTAGEELECTRIC HEAT SUPPLY AIR
MOTOREXHAUST OR ERV FAN
MOTOR(S)BASIC UNIT WITH EXHAUST FAN
AND ELECTRIC HEAT
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION
208-3-60
40 30
107.5 24.2 235 250
10 (5 x 2) 30.8 241 25015(7.5 x 2) 46.2 259 300
157.5 24.2 252 300
10 (5 x 2) 30.8 259 30015(7.5 x 2) 46.2 274 300
207.5 24.2 268 300
10 (5 x 2) 30.8 275 30015(7.5 x 2) 46.2 290 300
257.5 24.2 288 350
10 (5 x 2) 30.8 294 35015(7.5 x 2) 46.2 310 350
80 60.1
107.5 24.2 236 250
10 (5 x 2) 30.8 244 25015(7.5 x 2) 46.2 263 300
157.5 24.2 255 300
10 (5 x 2) 30.8 263 30015(7.5 x 2) 46.2 282 300
207.5 24.2 271 300
10 (5 x 2) 30.8 280 30015(7.5 x 2) 46.2 299 350
257.5 24.0 291 350
10 (5 x 2) 30.8 299 35015(7.5 x 2) 46.2 318 350
230-3-60
40 40
107.5 22 228 250
10 (5 x 2) 28 234 25015(7.5 x 2) 42 249 250
157.5 22 243 250
10 (5 x 2) 28 249 25015(7.5 x 2) 42 263 300
207.5 22 258 300
10 (5 x 2) 28 267 30015(7.5 x 2) 42 278 300
257.5 22 275 300
10 (5 x 2) 28 281 30015(7.5 x 2) 42 295 350
80 80
107.5 22 255 300
10 (5 x 2) 28 262 30015(7.5 x 2) 42 280 300
157.5 22 272 300
10 (5 x 2) 28 280 30015(7.5 x 2) 42 297 300
207.5 22 287 300
10 (5 x 2) 28 295 30015(7.5 x 2) 42 312 350
257.5 22 305 350
10 (5 x 2) 28 312 35015(7.5 x 2) 42 330 350
102777-YIM-B-0105
Unitary Products Group 37
460-3-60
40 40
107.5 11 112 125
10 (5 x 2) 14 115 12515(7.5 x 2) 21 123 125
157.5 11 120 125
10 (5 x 2) 14 123 12515(7.5 x 2) 21 130 150
207.5 11 127 150
10 (5 x 2) 14 130 15015(7.5 x 2) 21 137 150
257.5 11 136 150
10 (5 x 2) 14 139 15015(7.5 x 2) 21 146 175
80 80
107.5 11 127 150
10 (5 x 2) 14 131 15015(7.5 x 2) 21 140 150
157.5 11 136 150
10 (5 x 2) 14 140 15015(7.5 x 2) 21 149 150
207.5 11 144 150
10 (5 x 2) 14 147 15015(7.5 x 2) 21 156 175
257.5 11 152 175
10 (5 x 2) 14 156 17515(7.5 x 2) 21 165 175
108 108
107.5 11 161 175
10 (5 x 2) 14 165 17515(7.5 x 2) 21 174 175
157.5 11 170 175
10 (5 x 2) 14 174 17515(7.5 x 2) 21 182 200
207.5 11 177 200
10 (5 x 2) 14 181 20015(7.5 x 2) 21 190 200
257.5 11 186 200
10 (5 x 2) 14 190 20015(7.5 x 2) 21 199 225
TABLE 24: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 40 TON (Continued)
VOLTAGEELECTRIC HEAT SUPPLY AIR
MOTOREXHAUST OR ERV FAN
MOTOR(S)BASIC UNIT WITH EXHAUST FAN
AND ELECTRIC HEAT
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION
102777-YIM-B-0105
38 Unitary Products Group
575-3-60
40 40
107.5 9 92 100
10 (5 x 2) 11 94 11015(7.5 x 2) 17 101 110
157.5 9 99 110
10 (5 x 2) 11 101 11015(7.5 x 2) 17 107 110
207.5 9 105 125
10 (5 x 2) 11 107 12515(7.5 x 2) 17 113 125
257.5 9 111 125
10 (5 x 2) 11 113 12515(7.5 x 2) 17 119 125
80 80
107.5 9 105 110
10 (5 x 2) 11 108 11015(7.5 x 2) 17 115 125
157.5 9 113 125
10 (5 x 2) 11 115 12515(7.5 x 2) 17 123 125
207.5 9 119 125
10 (5 x 2) 11 122 12515(7.5 x 2) 17 129 150
257.5 9 125 150
10 (5 x 2) 11 128 15015(7.5 x 2) 17 135 150
108 108
107.5 9 133 150
10 (5 x 2) 11 136 15015(7.5 x 2) 17 143 150
157.5 9 141 150
10 (5 x 2) 11 143 15015(7.5 x 2) 17 151 175
207.5 9 147 150
10 (5 x 2) 11 150 15015(7.5 x 2) 17 157 175
257.5 9 153 175
10 (5 x 2) 11 156 17515(7.5 x 2) 17 163 175
TABLE 24: ELECTRICAL DATA BASIC UNIT W/ POWER EXHAUST & ELECTRIC HEAT - 40 TON (Continued)
VOLTAGEELECTRIC HEAT SUPPLY AIR
MOTOREXHAUST OR ERV FAN
MOTOR(S)BASIC UNIT WITH EXHAUST FAN
AND ELECTRIC HEAT
NOMINAL KW APPLIED KW HP HP FLA MCA MAX. OVERCURRENT
PROTECTION
102777-YIM-B-0105
Unitary Products Group 39
FIGURE 13 - BOTTOM SUPPLY AND RETURN
88.7"
CL
CL240"
38.59"83"
4.5"
4.5"
64"
92"
80.93"
SEE�
DETAIL�
A
26"
4.5"
15.89"
71.61"
127.5"
100.10"
128.50"
SEE
DETAIL�
CSEE
DETAIL�
B
OPEN
1-5/8" FPT FLANGED
FITTING
1-1/2" FPT
3.625"
6.46"
12"
1-1/4" FPT
10-1/4"
3-1/16"
1-1/4" FPT
3-5/8"
6.46"3-1/16"
MIN
14"MIN
12"MIN
BASE RAIL
BASE RAIL
DETAIL A(DRAIN CONNECTION)
DETAIL B DETAIL C(ELECTRICAL CONNECTION) (GAS CONNECTION,
THROUGH CURB)
NOTE: Hole must be drilled�
at job site.
4-5/8"
4-5/8"
FOR COOLING ONLY AND ALL HEATING APPLICATIONS
SUPPLY AIR
RETURN AIR
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102777-YIM-B-0105
40 Unitary Products Group
FIGURE 14 - END RETURN, BOTTOM SUPPLY
RETURN AIR
SUPPLY AIR
240"
64"
92"
80.93"SEE
DETAIL
A
100.10"
128.50"
SEEDETAIL
B
75.6"
OPEN
7-7/8"
8.15"76-3/824.9"
6.25"
26"
4.5"
15.89"
71.61"
SEEDETAIL
C
4-5/8"
1-1/2" FPT
3.625"
6.46"
12"
1-1/4" FPT
10-1/4"
3-1/16"
3-5/8"
6.46"3-1/16"
MIN
14"MIN
12"MIN
2-1/2"
NOTE:�
FACTORY INSTALLED POWER�
EXHAUST CANNOT BE ORDERED�
WITH END RETURN.
CL88.7"
4-5/8"
DETAIL A(DRAIN CONNECTION)
DETAIL B DETAIL C(ELECTRICAL CONNECTION) (GAS CONNECTION
THROUGH CURB)FOR COOLING ONLY AND ALL HEATING APPLICATIONS
NOTE: Hole must be drilled
at job site.
FIELD SUPPLIED
BASE RAIL
BASE RAIL
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�� ��
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102777-YIM-B-0105
Unitary Products Group 41
FIGURE 15 - BOTTOM RETURN, FRONT & REAR SUPPLY
FRONT SUPPLY: FOR COOLING ONLY APPLICATIONS�
REAR SUPPLY: FOR COOLING ONLY OR GAS HEAT APPLICATIONS
BASE RAIL
DETAIL A�
(DRAIN CONNECTION)
DETAIL B�
(ELECTRICAL CONNECTION)
BASE RAIL
DETAIL C�
(GAS CONNECTION�
THROUGH CURB)�
FIELD SUPPLIED
4-5/8"
4-5/8"
RETURN AIR
SUPPLY AIR
240"
38.59"83"
4.5"
4.5"
64"
92"
80.93"SEE�
DETAIL�
A
100.10"
128.50"
SEE�
DETAIL�
C
SEE
DETAIL�
B
26"
55"
75.6"
OPEN
8.15"
3.625"
6.46"
12"MIN
1-1/2" FPT
12"
1-1/4" FPT
10-1/4"
3-1/16"
2-1/2"
3-5/8"
6.46"
NOTE: Hole must be drilled�at job site.
3-1/16"
MIN
14"MIN
FRONT
FRONT
FRONT
REAR
REAR
LEFT SIDE
LEFT SIDE
REAR
RIGHT SIDE
RIGHT
SIDE
102777-YIM-B-0105
42 Unitary Products Group
FIGURE 16 - END RETURN, FRONT & REAR SUPPLY
FRONT SUPPLY: FOR COOLING ONLY APPLICATIONS
REAR SUPPLY: FOR COOLING ONLY OR GAS HEAT APPLICATIONS
RETURN AIR
SUPPLY AIR
240"
64"
92"
80.93"SEE�
DETAIL�
A
100.10"
128.50"
SEE�
DETAIL
C
SEE�
DETAIL�
B
26"
55"
75.6"
OPEN
7-7/8"
8.15"24.9"
6.25"
1-1/2" FPT
3.625"
6.46"
12"
1-1/4" FPT
10-1/4"
3-1/16"
2-1/2"
3-5/8"
6.46"
NOTE: Hole must be drilledat job site.
3-1/16"
MIN
14"MIN
12"MIN
76-3/8
BASE RAIL
BASE RAIL
DETAIL A�
(DRAIN CONNECTION)
DETAIL B�
(ELECTRICAL CONNECTION)
DETAIL C�
(GAS CONNECTION�
THROUGH CURB)�
FIELD SUPPLIED
26"
55"
4-5/8"
4-5/8"
�����
���
�����
���
��
���
��
���
���
���
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102777-YIM-B-0105
Unitary Products Group 43
FIGURE 17 - FIELD INSTALLED DISCONNECT
31"MAXIMUM
DRILL & BOLT
THROUGH UNIT
SHEET METAL
(4 PLACES)
34"*
6-1/2"
MINIMUM
MAXIMUM DOOR SWING
OF HEAT SECTION
DOOR WHEN OPEN
UNISTRUT
1-5/8" W x 7/8" H
OR EQUIVALENT
TM
47"
*34 INCHES IS THE MINIMUM LENGTH REQUIRED TOMOUNT TO THE FOUR POINTS SHOWN. THE RAILS CANBE EXTENDED TO MOUNT A TALLER DISCONNECTSWITCH, BUT THESE FOUR POINTS SHOULD BE USEDTO MOUNTTHE RAILS TO THE UNIT.
CFM, STATIC PRESSURE, AND POWER - ALTI-TUDE AND TEMPERATURE CORRECTIONS
The information below should be used to assist in applicationof product when being applied at altitudes at or exceeding1000 feet above sea level.
The air flow rates listed in the standard blower performancetables are based on standard air at sea level. As the altitudeor temperature increases, the density of air decreases. In
order to use the indoor blower tables for high altitude applica-tions, certain corrections are necessary.
A centrifugal fan is a "constant volume" device. This meansthat, if the rpm remains constant, the CFM delivered is thesame regardless of the density of the air. However, since theair at high altitude is less dense, less static pressure will begenerated and less power will be required than a similarapplication at sea level. Air density correction factors areshown in Table 25 and Figure 20.
The examples below will assist in determining the airflow per-formance of the product at altitude.
Example 1: What are the corrected CFM, static pressure,and BHP at an elevation of 5,000 ft. if the blower performancedata is 6,000 CFM, 1.5 IWC and 4.0 BHP?
Solution: At an elevation of 5,000 ft the indoor blower will stilldeliver 6,000 CFM if the rpm is unchanged. However, Table25 must be used to determine the static pressure and BHP.Since no temperature data is given, we will assume an airtemperature of 70°F. Table 25 shows the correction factor tobe 0.832.
Corrected static pressure = 1.5 x 0.832 = 1.248 IWC
Corrected BHP = 4.0 x 0.832 = 3.328
Example 2: A system, located at 5,000 feet of elevation, is todeliver 6,000 CFM at a static pressure of 1.5". Use the unit
blower tables to select the blower speed and the BHPrequirement.
Solution: As in the example above, no temperature informa-tion is given so 70°F is assumed.
The 1.5" static pressure given is at an elevation of 5,000 ft.The first step is to convert this static pressure to equivalentsea level conditions.
Sea level static pressure = 1.5 / .832 = 1.80"
Enter the blower table at 6000 sCFM and static pressure of1.8". The rpm listed will be the same rpm needed at 5,000 ft.
Suppose that the corresponding BHP listed in the table is 3.2.This value must be corrected for elevation.
1. Fan performance is based on wet evaporator coils, clean 2-inch throwaway filters and system/cabinet effects at standard air den-sity and 0 degree elevation.
2. Refer to Tables 29, 56, and 65 for component additions and deductions to fan performance tables.3. BHP does not include drive losses. Multiply BHP by 1.05 for drive losses.
1. Fan performance is based on wet evaporator coils, clean 2-inch throwaway filters and system/cabinet effects at standard air den-sity and 0 degree elevation.
2. Refer to Tables 29, 56, and 65 for component additions and deductions to fan performance tables.3. BHP does not include drive losses. Multiply BHP by 1.05 to account for drive losses.
TABLE 27: FAN PERFORMANCE - 30 TON 1 2 (Continued)
1. Fan performance is based on wet evaporator coils, clean 2-inch throwaway filters and system/cabinet effects at standard air den-sity and 0 degree elevation.
2. Refer to Tables 29, 57 and 66 for component additions and deductions to fan performance tables.3. BHP does not include drive losses. Multiply BHP by 1.05 to account for drive losses.
1. Fan performance is based on system/cabinet effects and backdraft damper effects at standard air density and 0° elevation.2. BHP does not include drive losses. Multiply BHP by 1.05 to account for drive losses.
102777-YIM-B-0105
60 Unitary Products Group
FIGURE 24 - POWER EXHAUST - ONE FORWARD CURVE FAN - 25 TONS
Power Exhaust 25 Ton
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0
CFM (x1000)
Tot
al S
tatic
Pre
ssur
e (I
WG
)
300400
500
600
700800
900
1000
1100
1200
1300
1400
1500
1600
5 BHP
7.5 BHP
10 BHP
102777-YIM-B-0105
Unitary Products Group 61
TABLE 33: POWER EXHAUST - TWO FORWARD CURVED FANS - 30 & 40 TON1
1. Fan performance is based on system/cabinet effects and backdraft damper effects at standard air density and 0° elevation.2. BHP includes the sum of both exhaust fan blowers.3. BHP does not include drive losses. Multiply BHP by 1.05 to account for drive losses.
102777-YIM-B-0105
62 Unitary Products Group
FIGURE 25 - POWER EXHAUST - TWO FORWARD CURVED FANS - 30 & 40 TONS
102777-YIM-B-0105
Unitary Products Group 63
START-UP COMPRESSOR ROTATION
Check for proper compressor rotation (See page 114 forsymptoms of reverse compressor operations). Millenniumunits are properly phased at the factory. If the blower, con-denser fan, or compressor, rotate in the wrong direction atstart-up, the electrical connection to the unit is misphased.Change the incoming line connection phasing to obtainproper rotation.
SUPPLY AIR FAN INSTRUCTIONS
CHECK BLOWER BEARING SET SCREWS
• The bearing set screws on the supply air blower are properly torqued before shipment. However, in transit they may loosen. Prior to start up they should be rechecked. The set screws are 3/8" and the torque range is 200 - 215 in.-lbs.
NOTE: If a unit is equipped with exhaust fans, those bear-ing set screws should also be rechecked. The setscrews are 1/4 inch and the torque range is 70 - 87in.-lbs.
CHECKING SUPPLY AIR CFM
The RPM of the supply air blower will depend on the requiredCFM, the static pressure resistances of the unit components(Tables 29, 56, 57, 65, and 66) and the static pressure resis-tances of both the supply and the return air duct systems.With this information, the RPM for the supply air blower canbe determined from the blower performance data in Tables26, 27, and 28. See Table 30 for pulley and drive informationfor the fixed pitch pulleys supplied on the unit.
The supply air CFM must be within the limitations shown inTable 2.
NOTE: If unit is equipped with power exhaust fans or returnair fan see Tables 32 and 33 for fan performanceand for pulley and drive information see Table 31.
FAN ROTATION
Check for proper supply air blower rotation. If fans are rotat-ing backwards the line voltage to unit point of power connec-tion is misphased (see Compressor Rotation above.)
NOTE: If unit is equipped with power exhaust fans or returnair fan also check them for proper rotation.
BELT TENSION
The tension on the belt should be adjusted as shown in Fig-ure 26 and Table 34.
NOTE: If unit is equipped with power exhaust fans or returnair fan check belt tension and adjust as necessary.
AIR BALANCE
Start the supply air blower motor. Adjust the resistances inboth the supply and the return air duct systems to balancethe air distribution throughout the conditioned space. The jobspecifications may require that this balancing be done bysomeone other than the equipment installer.
CHECKING AIR QUANTITY
Scroll compressors require proper rotation to oper-ate correctly. Units are properly phased at the fac-tory. DO NOT change the internal wiring to makethe blower, condenser fans or compressor rotatecorrectly.
FIGURE 26 - BELT TENSION ADJUSTMENT
On VAV and VFD units be certain all IGV’s on VAVunit are full open, VFD drive is set to maximumoutput, exhaust dampers are closed and individualspace damper boxes are full open.
VFD units with bypass must not have the bypassactivated unless all individual space dampers arefull open.
1. Remove the dot plugs from the two 5/16 inch holes in the blower motor and the filter access doors.
2. Insert at least 8 inch of 1/4 inch metal tubing into each of these holes for sufficient penetration into the air flow on both sides of the indoor coil.
3. Using an inclined manometer, determine the pressure drop across a dry evaporator coil. Since the moisture on an evaporator coil may vary greatly, measuring the pres-sure drop across a wet coil under field conditions would be inaccurate. To assure a dry coil, the compressors should be de-activated while the test is being run.
4. Knowing the pressure drop across a dry coil, the actual CFM through the unit with clean 2 inch filters, can be determined from the curve in Figure 61 and 62.
After readings have been obtained, remove the tubes andreinstall the two 5/16 inch dot plugs.
NOTE: De-energize the compressors before taking any testmeasurements to assure a dry evaporator coil.
TABLE 34: BELT ADJUSTMENT
FAN MOTOR HORSE POWER 5 7.5 10 15 20 25
30 TON FORWARD CURVED SUPPLY FAN SIZE: 22 X 20
Belt Deflection Force (lbs) new belts - - 10.5 12.6 15.2 22.1
Belt Deflection Force (lbs) old belts - - 7.1 8.5 10.2 14.8
40 TON FORWARD CURVED SUPPLY FAN SIZE: 25 X 20
Belt Deflection Force (lbs) new belts - - 10.5 12.6 15.2 15.2
Belt Deflection Force (lbs) old belts - - 7.1 8.5 10.2 10.2
30 & 40 TON POWER EXHAUST FAN SIZE: (2) 15 X 15
Belt Deflection Force (lbs) new belts - 7.9 9.4 9.4 - -
Belt Deflection Force (lbs) old belts - 5.3 6.3 6.3 - -
25 TON FORWARD CURVE SUPPLY FAN SIZE: 22 X 20
New Belt - 10.5 10.5 12.6 15.2 -
Old Belt - 7.1 7.1 8.5 10.2 -
25 TON POWER EXHAUST
New Belt 10.5 10.5 12.6 - - -
Old Belt 7.1 7.1 8.5 - - -
Failure to properly adjust the total system air quan-tity can result in extensive blower damage.
102777-YIM-B-0105
Unitary Products Group 65
SUPPLY AIR DRIVE ADJUSTMENT
At unit start-up the measured CFM based on Figures 61 and62 may be higher or lower than the specified CFM. Toachieve the specified CFM, the speed of the drive may haveto be decreased or increased by changing the pitch diameter(PD) of the motor sheave as outlined below:
• (Specified CFM/Measured CFM) X PD of standard sheave = PD of new sheave.
Use the following tables and the PD calculated per the aboveequation to select a new motor sheave.
EXAMPLE
• A 30 ton unit was selected to deliver 12,000 CFM with a 20 HP motor and a 966 RPM drive, but the unit is only delivering 11,000 CFM per Table 33.
• Use the equation to determine the required PD for the new motor sheave (12,000 CFM/11,000 CFM X 6.9” = 7.53 inch).
• Use the 30 ton Table 37.To select a Browning 2B5V74 which will increase the speed of the unit’s drive and its supply air CFM 108.7%.
• New drive speed = 1.087 X 966 = 1,050 RPM
• New supply air = 1.087 X 11,000 = 11,957 CFM
• Re-use the existing belts and blower sheave.
.
New motor BHP = (speed increase) 3 X estimated motor BHPto original start-up with 11,000 CFM and 966 RPM = (1.087)3
X 13.5 BHP = 1.284 X 13.5 BHP = 17.3 BHP New motoramps = (speed increase)3 X measured motor amps at originalstart-up with 11,000 CFM and 966 RPM.
SYSTEM SETPOINTS
Constant Volume and Variable Air Volume:
Thermostat and space sensor offsets must be made externalto the unit. For internal settings, refer to the Settable Parame-ters Table 52. All parameters affecting the unit with that spe-cific set of options and for that specific application must bereviewed. In many cases, the default settings will be fine - butverify and fine tune where necessary.
Before making any blower speed changes reviewthe installation for any installation errors, leaks orundesirable systems effects that can result in lossof air flow.
Even small changes in blower speed can result insubstantial changes in static pressure and BHP.BHP or AMP draw of the blower motor willincrease (see table 35) by the cube ratio of theblower speed. Static pressure will increase by thesquare ratio of the blower speed. Tables 36, 37and 38 are for reference only. All blower speedchanges must be made by qualified personnel withstrict adherence to the fan laws.
TABLE 35: BLOWER SPEED RATE OF CHANGE
CHANGE IN RPM
CHANGE IN
CFM TSPBHP AND MOTOR AMPS
.90 .90 .81 .73
.93 .93 .86 .79
.95 .95 .90 .86
.98 .98 .95 .93
1.00 1.00 1.00 1.00
1.03 1.03 1.05 1.08
1.05 1.05 1.10 1.16
1.08 1.08 1.16 1.24
1.10 1.10 1.21 1.33
1.13 1.13 1.27 1.42
1.15 1.15 1.32 1.52
1.18 1.18 1.38 1.62
1.20 1.20 1.44 1.73
102777-YIM-B-0105
66 Unitary Products Group
TABLE 36: 25 TON DRIVE ADJUSTMENT
7.5 HP Motor & 567 RPM Drive 10 HP Motor & 692 RPM Drive 15 HP Motor & 793 RPM Drive 20 HP Motor & 814 RPM Drive
%RPM& CFM
Req’d PD
Browning 2b5v_ _
%RPM& CFM
Req’d PD
Browning 2b5v_ _
%RPM& CFM
Req’d PD
Browning 2b5v_ _
%RPM & CFM
Req’d PD
Browning 2b5v_ _
- - - 81 4.2 42 83 5 50 85 5.8 58
- - - 85 4.4 44 87 5.2 52 88 6 60
- - - 88 4.6 46 90 5.4 54 91 6.2 62
- - - 92 4.8 48 95 5.7 57 94 6.4 64
- - - 96 5 50 97 5.8 58 97 6.6 66
100 4.2 42 100 5.2 52 100 6 60 100 6.8 68
105 4.4 44 104 5.4 54 103 6.2 62 103 7 70
110 4.6 46 108 5.6 56 107 6.4 64 109 7.4 74
114 4.8 48 112 5.8 58 110 6.6 66 118 8 80
119 5 50 115 6 60 113 6.8 68 126 8.6 86
124 5.2 52 119 6.2 62 117 7 70 - - -
129 5.4 54 123 6.4 64 123 7.4 74 - - -
TABLE 37: 30 TON DRIVE ADJUSTMENT
10 HP Motor & 617 RPM Drive 15 HP Motor & 743 RPM Drive 20 HP Motor & 856 RPM Drive “25 HP Motor & 933 RPM Drive”
TABLE 39: DRIVE ADJUSTMENT FOR POWER EXHAUST - 25 TON
5 HP Motor & 732 RPM Drive 7.5 HP Motor & 827 RPM Drive 10 HP Motor & 955 RPM Drive
%RPM& CFM
Req’dPD
Browning 2b5v_ _
%RPM& CFM
Req’dPD
Browning 2b5v_ _
%RPM& CFM Req’d PD Browning
2b5v_ _
100 4.9 46 92 5.1 48 93 5.9 56
104 5.1 48 96 5.3 50 97 6.1 58
109 5.3 50 100 5.5 52 100 6.3 60
113 5.5 52 104 5.7 54 103 6.5 62
117 5.7 54 108 5.9 56 107 6.7 64
122 5.9 56 112 6.1 58 110 6.9 66
102777-YIM-B-0105
68 Unitary Products Group
GAS FURNACE OPERATINGINSTRUCTIONS
TO LIGHT THE MAIN BURNERS
1. Turn off electric power to unit.
2. Turn space temperature sensor to lowest setting.
3. Turn gas valve knobs to on position (Refer to Figure 27).
4. Turn on electric power to unit.
5. On Constant Volume units, set space setpoint to warmer or cooler as desired. (If sensor set point temperature is above room temperature, the main burners will ignite). If a second stage of heat is called for, the main burners for second stage heat will ignite for the second stage heat. For VAV units set morning warm-up thermostat far above the return air temperature and cycle the time clock OFF, then ON.
TO SHUT DOWN
1. Turn off electric power to unit.
2. Depress knob of gas valve while turning to off position. (Refer to Figure 27).
POST-START CHECKLIST (GAS)
After the entire control circuit has been energized and theheating section is operating, make the following checks:
1. Check for gas leaks in the unit piping as well as the sup-ply piping.
2. Check for correct manifold gas pressures. See Checking Gas Input.
3. Check the supply gas pressure. It must be within the lim-its shown on rating nameplate. Supply pressure should be checked with all gas appliances in the building at full fire. At no time should the standby gas pressure exceed 13 inches, nor the operating pressure drop below 6 inches. If gas pressure is outside these limits, contact the local gas utility for corrective action.
MANIFOLD GAS PRESSURE ADJUSTMENT
Small adjustments to the gas flow may be made by turningthe pressure regulator adjusting screw on the automatic gasvalve. Refer to Figure 27.
Adjust as follows:
1. Remove the cap on the regulator. It's located next to the push-on electrical terminals.
2. To decrease the gas pressure, turn the adjusting screw counterclockwise.
3. To increase the gas pressure, turn the adjusting screw clockwise.
NOTE: The correct manifold pressure for each furnacemodule is 3.50 IWG 0.3.
TABLE 40: DRIVE ADJUSTMENT FOR POWER EXHAUST - 30 & 40 TON
7.5 HP Motor & 852 RPM Drive 10 HP Motor & 976 RPM Drive 15 HP Motor & 1069 RPM Drive
Each furnace module is equipped with an auto-matic re-ignition system. DO NOT attempt to man-ually light the burners.
102777-YIM-B-0105
Unitary Products Group 69
BURNER INSTRUCTIONS
To check or change burners, pilot or orifices, CLOSE MAINMANUAL SHUT-OFF VALVE AND SHUT OFF ALL POWERTO THE UNIT.
1. Remove the screws holding either end of the manifold to the burner supports.
2. Open the union fitting in the gas supply line just upstream of the unit gas valves and downstream from the main manual shut-off valve.
3. Disconnect wiring to the gas valves and spark ignitors. Remove the manifold-burner gas valve assemblies by pulling back.
4. Remove the heat shield on top of the manifold support.
Burners are now accessible for service.
Reverse the above procedure to replace the assemblies.Make sure that burners are level and seat at the rear of thegas orifice.
ADJUSTMENT OF TEMPERATURE RISE
The temperature rise (or temperature difference between thereturn air and the heated air from the furnace) must lie withinthe range shown on the CGA/ETL rating plate and the data inTable 3.
After the temperature rise has been determined, the CFM canbe calculated as follows:
After about 20 minutes of operation, determine the furnacetemperature rise. Take readings of both the return air and theheated air in the ducts (about six feet from the furnace) wherethey will not be affected by radiant heat. Increase the blowerCFM to decrease the temperature rise; decrease the blowerCFM to increase the rise. Refer to Table 30 for supply airblower motor and drive data. Minimum allowable CFM is6,000 CFM. Limit will open below this rating.
CHECKING GAS INPUT
NATURAL GAS
1. Turn off all other gas appliances connected to the gas meter.
2. With the furnace turned on, measure the time needed for one revolution of the hand on the smallest dial on the meter. A typical gas meter usually has a 1/2 or a 1 cubic foot test dial.
3. Using the number of seconds for each revolution and the size of the test dial increment, find the cubic feet of gas consumed per hour from Table 41.
If the actual input is not within 5% of the furnace rating (withallowance being made for the permissible range of the regu-lator setting), replace the orifice spuds with spuds of theproper size.
NOTE: To find the Btu input, multiply the number of cubicfeet of gas consumed per hour by the Btu content ofthe gas in your particular locality (contact your gascompany for this information - it varies widely fromcity to city).
FIGURE 27 - TYPICAL GAS VALVE
ManualShutoff
RegulatorCap
OutletPressureTap
TABLE 41: GAS RATE - CUBIC FEET PER HOUR
Seconds for One Rev.
Size of Test Dial
1/2 cu. Ft. 1 cu. Ft.
2 900 1800
4 450 900
6 300 600
8 225 450
10 180 360
CFM Btuh 0.8×1.08 F Degrees Temp Rise×--------------------------------------------------------------------------=
102777-YIM-B-0105
70 Unitary Products Group
Example: By actual measurement, it takes 7 seconds for thehand on the one cubic foot dial to make a revolution with justa 570,000 Btuh furnace running. Read across to the columnin Table 24, headed 1 Cubic Foot where you will determinethat 525 cubic feet of gas per hour are consumed by the fur-nace at that rate. Multiply 525 x 1050 (the Btu rating of thegas obtained from the local gas company). The result of551,000 Btuh is within 5% of the 570,000 Btuh rating of thefurnace.
ELECTRIC HEATING
The electric furnace is operational as shipped from the fac-tory and does not receive any field adjustments.
COOLING OPERATING INSTRUCTIONS
COMPRESSOR
Compressors are factory mounted ready for operation (Seepage 63 Compressor Rotation).
OIL LEVEL - All compressors are factory charged with oil.Each compressor is equipped with an oil level sight glass.Check for proper oil level which is approximately to the centerof the sight glass. Recheck oil level at startup.
INTERNAL WIRING
Check all electrical connections in the unit control box;tighten as required.
CONDENSER FANS
Check for proper condenser fan rotation; clockwise facing theair discharge. If condenser fans are rotating backwards, linevoltage to unit single point power connection is misphased(See page 63 Compressor Rotation).
MILLENNIUM SEQUENCE OF OPERATION
OVERVIEW
The Millennium Simplicity control has comprehensive rulesets to respond to heat and cool calls, provide anti-shortcycleand other safeties, date / time clock, and other features mak-ing the programmable thermostat unnecessary. The Millen-nium Simplicity extends on the rules of the Synthesys digitalcontrol.
With an attached (optional) Room Sensor, the control pro-vides calls for heating and cooling and occupied override.The control determines when to start morning warm-up,mechanical cooling, or heat based on parameter settings inthe Millennium Simplicity control, its internal time clock,Occupied and holiday schedules, the deviation from the set-points, and the rate of temperature change.
A separate thermostat cannot determine if an output functionis available. For example, if the belts on the supply fan wereto break, the thermostat would still call for the fan to operateand, if space conditions require, call for heating or cooling.Logic in the control prevents undesired operation of heatingand cooling stages, with interlocks and minimum run times.Moreover, the control can report faults on its digital display oron a network to a monitoring system.
Control logic is designed such that airflow must be provenbefore any heating or cooling stage can operate. Mechanicalcooling is locked out below 40°Foutdoor ambient for all unitswithout head pressure control. The control provides voltageto energize the contactors for the supply fan, cooling stages,heating stages, and options such as the economizer andpower exhaust. The thermostat makes calls for cooling andheating; the Simplicity control is responsible for executing therules putting these calls into action and protecting the unitthrough appropriate safety devices. If the Millennium Simplic-ity senses low voltage, it will hold any call that energizes acontactor until the voltage is adequate. It will not alarm for lowvoltage, but will provide a flash code.
The control also energizes the supply fan and cooling stagesbased on external inputs from the thermostat:
The economizer is enabled through settings in the controland operating conditions, or external BAS calls.
RUN SEQUENCE
The unit operates in one of three modes: Occupied, Unoccu-pied, and Recovery (Warm-up / Cool-down). The controlallows none, one, or two separate occupied / unoccupiedschedules for each day of the week, and twenty holidays. Inaddition to the programmed schedule, the space sensorallows a single key press to provide up to a 4-hour unoccu-pied override into the occupied mode.
OCCUPIED MODE: The supply fan operates continuously inthe Occupied and Recovery modes. The thermostat cyclescooling / heating to maintain the space temperature to theOccupied setpoints. Simplicity will enable optional econo-mizer and power exhaust features.
UNOCCUPIED MODE: The supply fan operates only withcooling / heating calls. The economizer is disabled during theunoccupied mode except when free cooling may be used tocondition the space. Cooling / heating stages are cycled tomaintain the space temperature to the Unoccupied setpoints.
RECOVERY MODE: A special unoccupied mode that allowstransition to occupied mode. The supply fan operates contin-uously and the economizer remains disabled. Instead ofmaintaining the unoccupied setpoints, the thermostat rampsthe space temperature toward the occupied setpoints. TheMillennium Simplicity control has an option for the control to“learn” how long it takes to get the building to the desiredtemperature, and adjust its start time to minimize the recov-ery time. Refer to the Intelli-Start section.
UNIT CONTROLS SEQUENCE
If the thermostat gives a call for G fan, W heating, or Y cool-ing, or the space sensor reading is not within the setpointrange; this is acted upon by unit control according to thesequence outlined below. A thermostat must not be con-nected anywhere but the appropriate labeled terminals.Direct control of compressors and heaters is not acceptable.
Abbreviations for various components correspond to thelabels on the wiring diagram.
1. On a call for the supply fan, voltage at terminal G is acted on by the control. If the supply fan overload is not tripped, voltage goes out from the FAN terminal on the control to either contactor 5M (Supply Fan Motor Starter) or relay FR (permission-to-run for the Variable Fre-
quency Drive). Power is applied to the airflow proving switch (APS). If the supply fan operates correctly (proper rotation), the pressure difference between the supply fan section and the heating section increases and APS closes to enable operation.
The air proving switch is monitored by the control 90 sec-onds after the fan is energized.
The control also monitors the supply fan overload. The overload circuit is wired directly to the control, not in series with the fan contactor. If the supply fan overload trips for longer than 5 seconds, the control will shut down the unit. If the trip clears within 15 minutes, the unit will log an error and resume operation. If the overload trips three times in two hours [or stays tripped longer than 15 minutes], the control will shut the unit down and report an alarm. In a VAV unit, the control will shut down the unit if the duct pressure shutdown setpoint is reached or exceeded.
2. Mechanical cooling stages have three monitoring cir-cuits: low pressure, high pressure, and internal [“mod-ule”] compressor overheat. They are connected to the control through the LPSx, HPSx, and C10, C20, etc., ter-minals. These allow the control to track specific error alarms, and let the control energize the next available compressor.
For units without optional head pressure control: If the outside air temperature rises above 50°F, the control enables all mechanical cooling stages. If the outside air temperature falls below 40°F and the unit does not have head pressure control, mechanical cooling stages are locked out.
For units with head pressure control: The first and second mechanical cooling stages are enabled when the ambient temperature rises above 10°F. When the ambi-ent temperature rises above 50°F, the third (on 30 and 40 ton) and fourth (40 ton only) stage mechanical cooling are enabled. If the outside air temperature falls below 40°F, mechanical cooling stages 3 and 4 (40 ton only) are locked out. If the outside air temperature falls below 0°F, all mechanical cooling stages are locked out. On units with optional heating, any call for heating engages
TABLE 42: COOLING STAGE
CALL ECONOMIZERMODE
MECHANICAL COOLING MODE
COOL 1 Economizer (N/A) Compressor 1
COOL 2 Compressor 1 Compressor 2
COOL 3 Compressor 2 Compressor 3
COOL4 Compressor 3 Compressor 4
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the supply fan. Operation of heating is dependent upon the APS closure.
When all run rules are satisfied, cooling stages are avail-able. A call for first stage cooling, Y1, initiates the control rules for cooling. When the control is satisfied [tempera-ture, short cycling timing, safety circuits, etc.], it sends voltage out terminal C1 to contactor 1M for compressor 1. If compressor 1 is not available, the control will start compressor 2 via C2 / 2M.
In Occupied mode, the economizer is enabled [if installed and the parameter set in the control]; if free cooling is available, the economizer will energize in place of the first cooling stage.
A thermostat call for second stage cooling powers termi-nal Y2, third stage powers Y3 (30 and 40 ton) and fourth stage powers Y4 (40 ton only). These thermostat calls are entered into the control’s logic, and available cooling stages brought on to meet the demand.
NOTE: The economizer may function when all mechanicalcooling stages are locked out on low ambient.
3. When the control calls for Compressor 1 (25 ton), or Compressor 1 or 2 (30 and 40 ton), it will also call con-denser fan stage 1 through terminal CF1, powering the coil of contactor 6M (condenser fan 1). On 25 ton units, condenser fan 2 (contactor 7M) is brought on by PS5 if discharge pressure on compressor 1 exceeds 280 psi. Fan 2 drops out if discharge pressure drops below 180 psi; condenser fan 4 (contactor 8M) is brought on by PS6 monitoring discharge pressure on compressor 2.
4. A control call for Compressor 2 powers contactor 2M through terminal C2, and CF2 (fan 3) on 25 ton units. On 30 and 40 ton units, because fans 1 and 2 pull through coils for both circuit 1 and circuit 2, the coil of contactor 7M (condenser fan 2) is powered in turn through either of condenser fan cycling switches PS5 or PS6, which enables condenser fan 2 operation if the discharge pres-sure of Compressor 1 or Compressor 2 exceeds 280 psi.
5. 30 and 40 ton only: A call for Compressor 3 powers con-tactor 3M (contactor, compressor 3) from terminal C3. A call for Compressor 3 or 4 also powers terminal CF2, second stage condenser fans (contactor 8M, condenser fan 3, and also contactor 9M, condenser fan 4 - 40 ton only).
6. 40 Ton Only: A call for Compressor 4 powers the coil of contactor 4M from terminal C4.
7. Gas Heat Option, Stage 1: a W1 call locks out cooling and initiates the control logic for Heat 1. The supply fan is engaged, at full speed if VAV-equipped. Once APS (air proving switch) closes to acknowledge supply airflow, power is supplied from terminal H1, which engages Igni-tion Control 1 (IC1) at heat module terminal W/TH. 24V is supplied to IC1 at terminal R/24V, and to the overtemp limit switch LS1, which opens only with excessive heat
exchanger temperature, on each gas heat module. That switch is monitored by connecting each limit switch to the LIM1, 2, or 3 terminal at the Simplicity board. IC1 closes contacts between terminals L1 and IND to engage Draft Motor 1. The 24V signal downstream from the overtemp limit switch goes through the vent motor air proving switch circuit to the PSW terminal on IC1.
With LS1 and PS1 closed, IC1 will attempt ignition. IC1 provides direct spark ignition with flame verification, and controls the GV1 gas valve through manual reset switch RS1 (rollout switch). If RS1 has tripped, GV1 is locked out and IC1 will electronically lockout after three failed ignition attempts. The Simplicity control monitors voltage to the gas valves through terminals GV1-3.
When the W1 call is canceled, power is removed from IC1 terminal TH, which directs IC1 to close GV1. As long as APS continues to prove supply fan airflow, IC1 remains powered and keeps the L1 to IND contacts closed for 45 {60??} seconds to maintain the operation of Draft Motor 1 for a postpurge of the heat exchanger.
8. Gas Heat Option, Stages 2 and 3: the Millennium Sim-plicity responds to W2 and W3 similarly to W1, if the unit is equipped with second and third heat modules.
9. Electric Heat Option: the Millennium Simplicity control allows staging electric heat. On units with the Electric Heat Option, a call for heat (W1) will initiate the main supply fan. When the Simplicity control is satisfied by the APS, it will complete the circuit to the first stage of elec-tric heat by energizing terminal H1. If additional heat is required, H2 will energize the second stage of electric heat [if the unit is so equipped], and H3 the third stage [if the unit is so equipped].
All electric heat modules have an auto-reset primary limit, monitored by the control, and non-restartable back-up limits. Dirty filters, broken belts, fan motor burn-out or running this unit below 6,000 CFM will cause the limit to trip on the auto-reset primary limit. In addition to the pri-mary limit, back-up limits may trip under these condi-tions. The backup limits are one-trip devices and will have to be replaced should they trip.
When a call for heat has been satisfied, the highest stage running will be de-energized until all are de-ener-gized.
10. Hot Water Heat Option: the unit will send a 2-10 VDC signal to drive a hot water valve.
Disconnect all power supplies before checking orservicing the electric heat section.
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11. Economizer Option: the control directly controls the posi-tion of the outside air / return air dampers through a 2-10 VDC signal from terminal ECO to ACT1 (economizer actuator). The economizer is enabled only in Occupied or Recovery mode, and after supply fan operation has been verified (APS closed). When the supply fan is pow-ered and there is no Y1 call or if free cooling is unavail-able, the control opens the economizer dampers to the minimum position setting.
The actuator maximum opening speed is 150 seconds to full open; the control moves the actuator at the rate of two seconds for each one % it is opening, so full open from closed would take 200 seconds. At entry to Occu-pied mode, the economizer is typically opening from 0 to a minimum setting of 20%, which would take about 40 seconds. In Unoccupied mode, the economizer will close to 0%.
With a Y1 call when the outside air is appropriate for free cooling (see below), free cooling is used for first stage cooling. The control modulates the economizer dampers to maintain a SAT setpoint plus or minus one degree.
The control uses one of three methods to determine when free cooling is available. The method used is determined by the unit options, which function as listed below.
Dry Bulb: the control relies on the RAT, OAT, and SAT readings, connected to those terminals on the control. Free cooling will be available until the outdoor tempera-ture rises above the indicated temperature range. Free cooling is disabled when the outdoor temperature rises above the temperature range and cannot be enabled until the outdoor temperature falls below the indicated temperature range.
Single Enthalpy: The Outdoor Air Humidity Sensor is connected to terminal OAH. When the outdoor enthalpy is below the setpoint, free cooling is available.
Dual Enthalpy (Comparative/Differential Enthalpy): Both the Outdoor Air Humidity [OAH] and the Return Air Humidity [RAH] sensors are connected to the control. When the outdoor air enthalpy is less than the return air enthalpy, free cooling is available. The control will dis-able free cooling and force mechanical cooling when the outside air temperature exceeds setpoints.
12. Power Exhaust Option with Modulating Dampers: The power exhaust controls are enabled in Occupied or Recovery mode when the APS is satisfied. The building pressure is sampled by a tube provided and installed by the customer at a location in the building, connected to the high pressure port of the pressure transducer BPS. BPS provides a 0-5 VDC signal to the control, which compares the reading to the pressure setpoint to control the exhaust dampers. The exhaust damper vanes are modulated by ACT2, from a signal from terminal EXD+. The exhaust motor is energized by voltage at terminal
EXH to contactor 10M when the dampers are driven above the ON setpoint for damper open %.
The exhaust motor is powered OFF when the vanes reach the OFF % point set in control parameters. When the power exhaust is disabled, ACT2's spring return closes the exhaust dampers and 10M opens to shut down the exhaust fans.
13. Power Exhaust Option with Variable Frequency Drive: The power exhaust controls are powered through EXH / 10M with a call for the supply fan. Once powered, the BPS sensor (Building Pressure sensor) sends a signal to terminal 53 of the VFD. The damper vanes are gravity-closed; motor speed is continuously variable. See sepa-rate document for details on power exhaust VFD opera-tion.
14. Non-modulating Power Exhaust Option: The power exhaust motor is energized by EXH / 10M based on the position of the Economizer damper settings in the control parameters. Minimum run time is 10 seconds; minimum off time is 60 seconds. The outlet pressure of the power exhaust fan forces the barometric relief dampers open; gravity closes the dampers when the exhaust fan is off.
VARIABLE AIR VOLUME UNIT (VFD & IGV)
OVERVIEW
The VAV units operate in one of three modes: Occupied,Unoccupied, and Recovery. The unit operational mode isdetermined by the status of the internal clock and the internalschedules.
OCCUPIED / UNOCCUPIED / MORNING WARM-UP
OCCUPIED
In Occupied mode, all installed options enabled by theparameter settings are available. The supply fan is operated[controlled to the duct pressure setpoint if a VAV], optionalunit heating is available at full capacity, the optional powerexhaust system is enabled, the economizer outside air damp-ers go to their minimum position or open for free cooling. Thisoperation continues until the unit enters Unoccupied mode.When the control sees an Occupied override button pushfrom the thermostat or space sensor, it will go to Occupiedmode for the length of time set in the parameters, up to fourhours. If the unit is in Space Sensor operation, the fan willoperate at full speed [controlled to the duct pressure setpointif a VAV].
A VAV standalone unit will run MWUP the first hour of theOCC override signal, then go to Occupied. The supply fan willrun continuously.
UNOCCUPIED
In Unoccupied mode, the economizer goes to full closed; thesupply fan will only operate if there is a call for heating or
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cooling [controlled to the duct pressure setpoint if a VAV]. Ifheating is required, all installed stages will be energized.
MORNING WARM-UP [MWUP]
The unit enters a morning warm-up mode going in to the firstOccupied period of the control’s internal daily schedule. Inthis mode, the supply fan is operated at full volume, optionalunit heating is engaged at full capacity if needed, the optionalpower exhaust system is enabled, the economizer outside airdampers close (return air dampers open), cooling is disabled,and voltage is provided at H1 to signal the remote VAV boxesto open. This operation continues until the return air tempera-ture exceeds the adjustable setpoint of the Morning Warm-upbulb thermostat (MWUP).
The parameter for MWUP must be turned on. Without Intelli-Start, MWUP will start one hour ahead of Occupied. Coolingwill not start until the Occupied mode starts. In MWUP, thecontrol will operate the fan and energize heat after monitoringRAT five minutes after going into MWUP, or if RAT goes twodegrees below the MWUP setpoint.
UNIT CONTROLS
1. The control reviews parameters, the unit clock, and occupied / Holiday schedules to select the appropriate mode. In Occupied mode, the unit will look at inputs enabled by parameter settings. It will default to second-ary inputs if necessary.
When the unit is running in Occupied mode, the duct pressure controller, if that option is installed, is activated; the optional power exhaust system is activated, power is applied to the airflow proving switch (APS), and to the supply fan motor contactor (5M) to engage the supply fan. If the supply fan operates correctly (proper rotation) the pressure difference between the supply fan section and the heating section increases and APS closes to enable operation. The control waits 75 [90??] seconds for the fan to reach equilibrium, then looks at the APS.
For units without optional head pressure control: If the outside air temperature rises above 50°F the control enables all mechanical cooling stages. If the outside air temperature falls below 40°F, then all mechanical cooling stages are locked out.
For units with head pressure control: Enable third and fourth (40 Ton only) stage mechanical cooling when the ambient temperature rises above 50°F. If the outside air temperature falls below 40°F, mechanical cooling stages 3 and 4 (40 Ton only) are locked out. Enable first and second stage mechanical cooling when the ambient tem-perature rises above 10°F. If the outside air temperature falls below 0°F, all mechanical cooling stages are locked out.
2. While the return air temperature remains below the set-point of MWUP (Morning Warm-up), engage the unit heat (optional) at full capacity.
For Inlet Guide Vane VAV: terminal VFD provides a 10VDC signal for the actuator, thus forcing the inlet guide vane dampers to fully open during the warm-up cycle. Terminal H1, heat stage 1, is used to signal the remote VAV boxes to open. In this warm-up mode, VAV and the economizer (optional) are disabled, so cooling is disabled and the optional economizer outside air damp-ers are closed.
3. When the return air temperature climbs above the MWUP setpoint, heating is disabled, VAV and the econo-mizer are enabled.
4. A call for first stage cooling initiates the cooling sequence. The optional economizer is enabled, and drives the damper to the minimum open position. If free cooling is available, dampers open to satisfy setpoints. If there is no economizer, the control powers terminal C1 to energize compressor 1.
The control provides a minimum of 30 seconds between each cooling stage call [see Lead-Lag], a 4 minute mini-
The bypass VFD is a standard Variable FrequencyDrive packaged with a further set of contactorsWhen bypass mode is activated, contactors routepower around the VFD, connecting the indoor fanmotor direct to supply voltage. At this point themotor will go to full RPM regardless of the ductpressure signal, because the VFD is out of theloop, and there is a potential for over pressuringthe ducts.
The air balancer must set maximum duct static /CFM to stay within a static pressure that the duct-work of that installation can tolerate when themotor is at full RPM, considering that the VAVboxes, if they are part of the system, may not befull open.
If the duct system includes VAV boxes, they mustbe driven open in Bypass mode in the same man-ner as going to heat mode. The drive indicatesbeing in “bypass” mode with normally open con-tacts wired to terminal block 1, position 5 and 6across Danfoss relay M3 [refer to drawings sup-plied by Danfoss, packed with the unit].
Voltage sufficient to signal the boxes to open mustbe wired through this contact. This is a field-installconnection.
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mum ON time for each cooling stage and a 5 minute min-imum OFF time for each cooling stage.
5. A call for Compressor 1 powers the high pressure safety switch (HPS1), the low pressure switch (LPS1), the coil of contactor 6M (condenser fan 1), and the coil of con-tactor 7M (contactor, condenser fan 2) through con-denser fan cycling switch PS5 (PS5 disables condenser fan 2 operation based upon the discharge pressure of the Compressor 1). If the system pressures are within HPS1 (high refrigerant pressure) and LPS1 (low refriger-ant pressure) switch settings and the solid state com-pressor motor protector (Compressor Module No. 1) is not tripped, contactor 1M is engaged to start scroll Com-pressor 1.
6. A call for Compressor 2 powers contactor 2M (contactor, compressor 2) if HPS2, LPS2 (high and low refrigerant pressure) and Compressor Module 2 (compressor motor protector) contacts are closed.
7. 30 and 40 ton only: A call for Compressor 3 powers the coils of contactors 8M (contactor, condenser fan 3) and 9M (contactor, condenser fan 4 - 40 ton only). If HPS3, LPS3 (high and low refrigerant pressure) and Compres-sor Module 3 contacts are closed, power is applied to the coil of Contactor 3M, which starts compressor 3.
8. 40 Ton Only: A call for Compressor 4 powers the coils of contactor 4M if HPS4, LPS4 (high and low refrigerant pressure) and Compressor Module 4 contacts are closed.
9. When the internal time clock matches the setting in the holiday and daily schedules, the unit enters Unoccupied mode. The control disables the supply fan, the optional power exhaust, cooling, heating, and the economizer. The optional outside air dampers are closed with the optional inlet guide vanes.
10. When the space temperature falls below the heating set-point, the control powers contactor 5M from terminal FAN to engage the supply fan motor. If the supply fan operates correctly (proper rotation) the pressure differ-ence between the heating section and the supply fan section increases and APS closes to enable heating operation. If heat safeties are satisfied, the VAV speed signal (VFD or Inlet Guide Vanes) goes to maximum flow [the customer-installed connection will drive the VAV boxes to full open]. The control engages unit heat (optional) at full capacity. Until heat is energized, duct pressure control is activated. The optional power exhaust system is activated.
In heat mode, cooling is disabled and the optional econ-omizer outside air dampers are closed. This operation is maintained until the space temperature rises above the heating setpoint or Occupied mode is engaged.
11. Gas Heat Option, Stage 1: A call for heat engages Igni-tion Control 1 (IC1-terminal TH) from Simplicity terminal H1. Once APS (supply air proving switch) closes to
acknowledge supply airflow and the LIM1-3 safeties are satisfied, IC1 is powered. IC1 closes contacts between terminals L1 and IND to engage Draft Motor 1. The IC1 monitors PSW (draft fan air proving switch) and LS1 (heat limit switch, which opens only with excessive heat exchanger temperature). When the safeties are satisfied, IC1 will attempt ignition. IC1 provides direct spark igni-tion with flame verification and controls the GV1 gas valve through manual reset switch RS1 (rollout switch). If RS1 has tripped, GV1 is locked out and IC1 will electron-ically lockout after 3 failed ignition attempts. The Simplic-ity control also monitors the voltage going to the gas valve at terminals GV1-3.
When the W1 call is canceled, power is removed from IC1 terminal TH, which directs IC1 to close GV1. As long as APS continues to prove supply fan airflow, IC1 remains powered and keeps the L1 to IND contacts closed for 45 seconds to maintain the operation of Draft Motor 1 for a post-purge of the heat exchanger.
12. Gas Heat Option, Stages 2 and 3: These follow the same rules as Stage 1. Separate terminals and safety monitor circuits are wired to each installed heat stage. For gas heat, there is a separate overtemperature limit switch for each heat module.
13. Electric Heat Option: A call for heat stages electric heat on. Electric heat is available as 40kW [one stage], 80kW [two stages], or 108kW [three stages]. There is one over-heat limit for electric heat, regardless of the number of stages - contrasted with gas heat, which has individual over-heat limits on each module.
On units with the Electric Heat Option, a call for heat (W1) will initiate the main blower. The blower will pro-duce static in the supply and the Air Proving Switch (APS) contacts will close. The control recognizes closure of the APS and energizes the H1 terminal to complete the circuit to the first stage of electric heat.
In Occupied mode, if additional heat is required, the W2 signal will energize the second stage of electric heat through terminal H2; W3 / H3 function similarly. When the W2 call for heat has been satisfied, W2 will be de-energized and will in turn de-energize H2 second stage heat. As the call heat (W1) has been satisfied, W1 will be de-energized. If the unit is in Unoccupied mode, the fan will shut off and the APS will open. For units in space sensor control, the Simplicity will stage on heat as required to maintain space sensor temp, or SAT temp if the space sensor signal is lost.
All electric heat modules have an auto-reset primary limit and non-restartable back-up limits. Dirty filters, broken belts, fan motor burn-out or running this unit below 6,000 CFM will cause the limit to trip on the auto-reset primary limit. In addition to the primary limit, back-up limits may trip under these conditions. The back-up limits are one-trip devices and will have to be replaced should they trip.
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14. When the space temperature rises above the Unoccu-pied cooling setpoint, the control enables optional duct pressure control and optional power exhaust system; power is applied to the airflow proving switch (APS) and to the coil of starter 5M to engage the supply fan motor. If the supply fan operates correctly (proper rotation) the pressure difference between the heating section and the supply fan section increases and APS closes to allow mechanical cooling operation. The unit operates as though it were in the Occupied mode (see above) until the space temperature falls below the cooling setpoint or Occupied mode is engaged.
15. Duct Pressure Control - Inlet Guide Vane Option: The duct pressure controls are powered with a call for the supply fan. Once powered, the pressure transducer DPS provides a voltage signal input to the Simplicity control. The control calculates a 2-10VDC signal to the inlet guide vane actuator.
16. Duct Pressure Control - VFD (Variable Frequency Drive) Option: The duct pressure controls are powered with a call for the supply fan. Once powered, the VFD responds to a VDC control signal from the DPS (Duct Pressure transducer). In the heating mode the VDC, DPS pressure signal forces the fan to full volume. VAV boxes should be tied to the H1 terminal to signal the boxes to full open.
17. Electronic Economizer Option: The control directly controls the position of the outside air / return air damp-ers through a 2-10 VDC signal to ACT1 (economizer actuator). The economizer is powered only after supply fan operation has been verified (APS closed) and the unit is in Occupied or Recovery mode. When the control is not powered or is in Unoccupied mode, the outside air dampers spring return closed. When in Occupied or Recovery mode and there is no Y1 call or if free cooling is unavailable, the Simplicity control opens the econo-mizer dampers to the minimum position setting made in the parameters.
With a Y1 call where the outside air is appropriate for free cooling (see below), the control modulates the vanes for free cooling in place of first stage cooling. (Please see the compressor staging chart above.) The control modulates the economizer dampers to maintain a Mixed Air Temperature (Return Air / Outside Air Mixture, sensed between the filters and the DX coil) between 50°F and 55°F (adjustable between 40°F and 65°F).
The Simplicity control uses one of three methods to determine when free cooling is available. The method used is determined by the option selection.
Dry Bulb: The control refers to input from the OAT, and will allow free cooling when the outdoor temperature falls below the Economizer First Stage temperature setpoint. Free cooling will be available until the outdoor tempera-ture rises above the temperature setpoint.
Single Enthalpy: the control will consider, along with outside temperature, outside air humidity [OAH sensor; parameter must be set to ON] in enabling free cooling. The outside air enthalpy setpoint parameter [BTU per pound] must also be set.
Dual Enthalpy (Comparative/Differential Enthalpy): Both the Outdoor Air Enthalpy and the Return Air Enthalpy [RAH sensor, option parameter must be set to ON] are connected to the control. The setpoint when the outdoor air enthalpy is less than the return air enthalpy, free cooling is available. The rules in the control will lock out free cooling and force mechanical cooling when the outside air temperature exceeds setpoints.
18. Power Exhaust Option with Modulating Dampers: The power exhaust controls are enabled in Occupied mode. The building pressure sensor [BSP] provides a signal to the control. The exhaust dampers are modu-lated by a 2-10VDC signal from the control, proportional to the pressure sensed, to the damper actuator. When the actuator opens the damper more than the parameter “Exhaust Damper Position for Exhaust Fan to Turn ON” setting, the Simplicity control powers the 10M starter to engage the power exhaust fan motor. When the dampers reach the ”Exhaust Damper Position for Exhaust Fan to Turn OFF” setting, the control turns the motor off. When the power exhaust is disabled, the control closes the exhaust dampers.
19. Non-Modulating Power Exhaust Option: The power exhaust controls are enabled by the Simplicity control. The control powers the exhaust fan motor by monitoring the position of the economizer damper vanes [“Econo-mizer Damper Setting for Exhaust Fan to Turn ON [OFF]”]. The outlet pressure of the power exhaust fan forces the barometric relief dampers open. Exhaust Fan operation is continued until the economizer reaches the % set in the parameter Gravity closes the barometric relief dampers when the exhaust fans are off.
20. Power Exhaust Option with Variable Frequency Drive (VFD): The power exhaust controls are enabled through the Simplicity control. The variable frequency drive is controlled by a signal from the control, based on the Building Pressure sensor (BPS), located in the control box, which translates the building pressure signal to a VDC signal. Fine tuning is accomplished by setting parameters in the VFD [ref: separate instruction].
NOTE: Modulated exhaust: Pressure-tap tubing must berun from an appropriate location in the building tothe "high" port on the BPS transducer. Dampers onthe VFD power exhaust are gravity-closed and arenot modulated. The BPS signal is proportional withthe difference between outside ambient pressureand building pressure. The VFD is set for a mini-mum speed of 33% and a maximum of 100%. TheVFD parameters are factory set, specific for eachcontrol system, and are detailed on a sticker by thedrive. The drive manual is shipped with the unit.
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NOTE: For smoke purge, etc., special connections: forstandard controls, consult a controls specialistfamiliar with your local codes.
HEAD PRESSURE CONTROL
DESCRIPTION
The head pressure control option controls the speed of con-denser fan 1 for low ambient mechanical cooling operation ofsystems 1 and 2. This option functions independently of theSimplicity control.
The option includes two pressure transducers and a variablefrequency drive. The pressure transducers are connected tothe discharge line of system 1 and 2. The VFD modulates tothe higher signal; if either system 1 or 2 exceeds 280 psi, asecondary mechanical switch close to turn on fan 2. Typicallythe modulated fan will slow down; if both systems drop below180 psi, fan 2 drops out.
System 3 on a 30 ton and system 3 and 4 on a 40 ton arelocked out below 45°F ambient.
NOTE: Altering the factory settings could result in poor con-trol or operation of the system.
No special motor is required on three-phase systems; singlephase systems will use three phase motors on fan 1. Thevariable Frequency Drive is pre programmed at the factory.
SEQUENCE OF OPERATION - FOR HEAD PRES-SURE CONTROL
A call for the first stage cooling powers the 6M contactorenergizing the variable frequency drive. The drive will ramp tothe pre programmed minimum speed of 20 Hertz immediatelyupon start up. As the discharge pressure on system 1 or 2compressor rises, the transducer output signal to the variablefrequency drive rises. The drive will increase the speed ofcondenser 1 fan, maintaining a setpoint of 240 PSI.
The scroll compressor produces a rapid rise in dischargepressure upon start up. This usually will result in full speedoperation of condenser fan 1. After the discharge pressurehas settled out, the speed of condenser 1 may decreaseespecially during times when the ambient temperature isbelow 80°F. After the 1 system has stabilized and compressor
2 is energized, the speed of condenser Fan 1 will increase tocompensate for the discharge pressure rise. Typically, sincefan 2 will run at full speed, fan 1 will slow down when fan 2energizes.
As the ambient temperature drips below 40°F the 1 con-denser fan will slow to the minimum speed. The circuit 2 con-denser fan will disengage when the discharge pressure dropsbelow 180 PSIG as the ambient temperature falls. The dis-charge pressure of system 1 and/or 2 will increase when con-denser fan 2 stops, consequently causing an increase in thespeed of condenser fan 1.
The Millennium Simplicity control includes a terminal SD forthe user to wire a signal to shut down, and a Purge terminalto signal the unit to shut off heat or mechanical cooling, openthe economizer and exhaust dampers, and run the exhaustfan [depending on which options are installed on the unit].
INTELLI-START
If Intelli-Start is enabled the control will use that calculation todetermine when to start Morning Warm-Up. If the Intelli-Startoption is not enabled, the control will start Morning Warm-Upone hour before Occupancy.
When Intelli-Start is enabled, the control will attempt torecover the building to the Occupied Setpoint by the time theOccupied period begins. On the first day when the controlhas nothing stored for recovery, it will go “Occupied” twohours before the Occupied period. The control will store thebeginning demand and track the time it takes to reach theOccupied Setpoint. When the Occupied setpoint is reached,the control will store how long it took, and use that warm-upability to calculate the period needed the next time it runs.The control will store the recovery value separately for Heat-ing and Cooling. Unoccupied Recovery will only run on thefirst Occupied period of the day. It will always be operating onthe previous day’s performance. The Economizer will beused if free cooling is available.
Millennium Simplicity will accommodate inputs for water coilfreeze stat, SA sensor, ODA sensor, Space sensor, andRoom sensor, Building pressure sensor, Duct pressure sen-sor, Demand ventilation, RA humidity, OD humidity, RS485communications.
LEAD LAG
When this option is set ON, the unit will equalize run time oncompressors [except for compressor 1 if the head pressurecontrol option or hot gas bypass is installed].
DEVICES AND RULES
This chapter describes the many control modes of operationfor Simplicity. Because of the narrative and detailed descrip-tions contained in this section, you should only scan thischapter and become familiar with the primary topics. Then,
All power exhaust options require that the cus-tomer provide tubing connections to the trans-ducer from a representative location in thebuilding; modulating-vane and VFD exhausts willopen full / power on in Purge mode
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use this chapter as a reference whenever a more detailedunderstanding of a particular mode is needed.
You should keep in mind that, especially with digital controls,interlocking between control modes is common and easilyachieved. Also, by the very nature of digital control program-ming, many simultaneous rules can be implemented becausethey generally require only software programming and verylittle peripheral hardware. This reduces the costs associatedwith manufacturing and servicing equipment with this level ofinteracting features - but you can’t see the status of inter-locked rules as you can with discreet relays.
Several control modes will override other modes of operation.
For example, The Demand Ventilation (or, Indoor Air Quality)control may override Comfort Ventilation / Economizer controland drive the OA dampers above the established minimumposition. The Excessive SAT control will override all tempera-ture control modes, Economizer mode, and compressor oper-ation as well. If you suspect that a problem exists with theeconomizer, or the compressors are locked out when noalarms are set, verify that one of the control modes is notoverriding the normal mode of operation or the operation youmight expect to see. Another important example is the AirProving Switch interlocking mode. If the Air Proving Switchalarms on a VAV unit, the unit will refer to the duct pressuresensor; if duct pressure is present, the control will assumethe fan is working even though the APS is not.
If the fan status [APS] fails, and the duct pressure switch of aVAV unit sees no duct pressure, all controlling algorithms andoperations, and outputs (except hydronic heat) will cease andthe control will shut down all outputs.
AIR PROVING SWITCH
When the control starts the supply fan, it waits 90 seconds tocheck for closure of the Air Proving Switch (APS). If the APSdoes not close, the control will turn off all outputs except Fanand the VFD speed signal, flag an alarm, and flash an alarmon the display. If it is a VAV unit, the control will look to theduct pressure signal; if it is above .05”, the control will flag abad APS and continue operation.
It will retry the Fan output every 30 minutes for three retries. Ifafter three retries it still cannot qualify the Fan, it will Alarmand lock all heating and cooling operation out. If the switchcloses after an alarm has been flagged, the control willresume normal operation and clear the active alarm.
After the control has turned off the fan, it will wait 90 secondsand verify that the switch opens. If the switch does not openafter 90 seconds, the control will flag a failed switch and flashthe alarm. On the next startup, the control will stage up equip-ment normally.
This switch-closed failure mode of the Air Proving Switch canonly be detected with the Supply Fan off. It is important to
detect because it effectively disables the fan failure alarmchecking while fan is running, described in the paragraphsabove. Those checks would always pass as the switch wouldremain closed. In networked applications, the error flag isreadable by the network. The alarm will automatically resetafter the problem that caused it has been corrected.
When the control is running the fan and the APS has alreadybeen proven, and then it opens, the control will wait 2 sec-onds before shutting down heating, cooling, and locking out.It will alarm and retry as if it happened during start-up.
FAN DELAYS:
There are separate Fan ON and OFF delay periods for heat-ing and cooling, to reduce the momentary change in SAT.
COMFORT VENTILATION MODE
Comfort Ventilation is a control mode that uses the econo-mizer to modulate SAT. Where possible, the economizer willmodulate the outside / return air mix to keep SAT within theupper and lower Comfort Ventilation setpoints. The controlwill modulate the economizer, and energize cooling or heat-ing if necessary, to keep SAT within the Comfort Ventilationsetpoints, even though space temperature may be satisfied.
For example, minimum economizer position can take SAT outof the Comfort Ventilation range, requiring heat or coolingthat the thermostat isn’t calling for. The result of comfort ven-tilation control is less variation of SAT, and fewer on-off cyclesof mechanical cooling or heating. If turning off a cooling stageraises SAT above the upper setpoint, but leaving it runningwill take SAT below the lower setpoint - then the compressoris left on, and warmer outside air is brought in to raise SAT tothe lower setpoint to keep a compressor from cycling off.Similarly, if leaving a heat stage on will raise SAT above theUpper setpoint, the control will leave heat on and modulatecooler outside air into the mix.
FIGURE 29 - COMFORT VENTILATION ECONO-MIZER CONTROL
High Supply Air Setpoint
Economizer Control Setpoint
(Middle of SAT Control Band)
Low Supply Air Setpoint
SAT Control Band
(Gray Area)
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The Comfort Ventilation temperature-band minimum width isfive degrees. Comfort Ventilation high and low setpoints willbe within the Cooling Upper and Heating Lower setpoints.
Without using the Comfort Ventilation mode where available,when the space temperature control loop is satisfied (zerodemand), all cooling and/or heating stages would be turnedoff and the SAT would be allowed to float until the space tem-perature control loop again generates a call for cooling orheating. The supply fan may be kept on during the “satisfied”periods, or may be turned off, depending on thermostat set-tings, or “Fan ON mode with the Sensor” option setting.
If Comfort Ventilation is selected, it will take priority over sup-ply fan control and keep it running during the “satisfied” peri-ods, when there is no call for heating or cooling. The ComfortVentilation mode is used to optionally replace the uncon-trolled, floating SAT situation during the “satisfied” periodswith a “loose” SAT control in a fairly wide temperature band(between specified Comfort Ventilation Upper Setpoint andComfort Ventilation Lower Setpoint). This may require someadditional energy, but improves space comfort (e.g. instead ofbringing a very hot and humid ventilation / outdoor air intospace during the “satisfied” periods, the ventilation air tem-perature is “trimmed” to be within the specified SAT controlband).
Comfort Ventilation mode terminates when there is a call forheating or cooling from the space temperature control.
• Comfort Ventilation can be used only on units equipped with an Economizer.
• Comfort Ventilation only operates in an Occupied mode.
• “Comfort Ventilation Mode” must be set to ON (default setting is OFF).
The modulating range of the economizer dampers are limitedby a specified Economizer Minimum Position and by a speci-fied Comfort Ventilation Maximum Economizer Setpoints.
The Economizer capability to control SAT may be further lim-ited in case the Demand Ventilation Operation is enabled andoverrides the economizer to a more-open position in order tosatisfy space IAQ requirements. The values of “Comfort Ven-tilation Upper Setpoint” and “Comfort Ventilation Lower Set-point” would typically be set such that they are centeredaround an expected return air temperature. The bandbetween the two setpoints should be set wide enough so thatSAT changes due to staging / destaging compressors, orheating stages, can be compensated for by the economizercontrol such that staging / destaging is minimized. Also, awider band minimizes use of additional energy during unit’s“satisfied” periods.
ECONOMIZER CONTROL DURING COMFORT VENTILA-TION
Economizer control uses a Proportional-Integral control algo-rithm that maintains SAT within the specified SAT band by
modulating the economizer dampers. The PI algorithm set-point is calculated as a midpoint between the programmed"Comfort Ventilation Upper Setpoint" and "Comfort VentilationLower Setpoint". As the controller uses outside air to maintainthe SAT at the setpoint, it must be capable of self-configura-tion for Direct, or Reverse action, depending on the relation-ship of the OAT to the specified SAT control band:
• If the OAT is below the specified SAT band low setpoint ("Comfort Ventilation Lower Setpoint"), the action is Direct Acting. In this case, the economizer control can lower the SAT temperature just by opening the econo-mizer damper and using more outdoor air. However, if the economizer algorithm can not prevent the SAT from dropping below the bottom control band limit by closing the economizer damper to its programmed minimum position, one or more heating stages may need to be turned on. Similarly, if the economizer algorithm can not prevent the SAT from increasing above the top control band limit, one or more compressors may need to be turned on.
• If the OAT is above the specified SAT band high setpoint ("Comfort Ventilation Upper Setpoint"), the action is Reverse Acting. In this case, the economizer control can increase the SAT temperature just by opening the econ-omizer damper and using more outdoor air. However, if the economizer algorithm can not prevent the SAT from increasing above the top control band limit by closing the economizer damper to its programmed minimum posi-tion, one or more compressors may need to be turned on. Similarly, if the economizer algorithm can not prevent the SAT from dropping below the bottom control band limit by opening the economizer damper, one or more heating stages may need to be turned on.
• If the OAT is within the SAT control band, i.e. between the programmed "Comfort Ventilation Upper Setpoint" and "Comfort Ventilation Lower Setpoint", the econo-mizer damper is driven to the fully open position. In this case, no other control action needs to be taken to main-tain the SAT within the specified control band.
STAGING CONTROL DURING COMFORT VENTILATION
The economizer control alone may not be able to maintainthe SAT within the specified control band. A separate stagingcontrol algorithm supplements the economizer control andwill stage heating, or mechanical cooling as necessary. If theSAT increases above the "Comfort Ventilation Upper Set-point" for more than 5 minutes, the control will destage aheating stage (if any heating stages running), or add a com-pressor. The control will repeat this process every 5 minutesuntil the SAT gets back to within the control band.
If the SAT drops below the "Comfort Ventilation Low SupplyAir Setpoint" for more than 5 minutes, the control will destagea compressor (if any compressors running), or add a heatingstage. The control will repeat this every 5 minutes until theSAT gets back to within the control band. As the heating
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stages, or compressors are staged up, or destaged, theeconomizer controls continues using the economizer damperto "trim" the effect of the staging and to maintain the SAT asnear the middle of the SAT control band as possible.
If the unit is using hydronic heat, the control modulates thewater valve to maintain SAT at the programmed "ComfortVentilation Low Supply Air Setpoint". At this setpoint, thehydronic heat control does not conflict with the economizercontrol, and will prevent SAT from dropping outside of thespecified control band when the economizer can no longermaintain the SAT at its middle-of-the-band setpoint.
HYDRONIC HEAT
The Hydronic Heat option requires locating a SAT sensordownstream of the heating coil.
During hydronic heating, the SAT control to the selected“Hydronic Heat First Stage SAT setpoint”, or “Hydronic HeatSecond Stage SAT Setpoint” is performed using a Propor-tional / Integral control algorithm. The control algorithmincludes special provisions (sometimes referred to as a“bumpless transfer” feature) that allow it to resume control ofSAT as fast as possible when it is re-activated during the ON/ OFF cycling of the unit (cycling between a satisfied and aheating state under control of a zone thermostat, or zonesensor). In its OFF-state, the control algorithm continuesmonitoring the SAT and performs calculations necessary toset its output, that controls the hot water valve, to have thesame value on starting the ON-cycle as it had when it wentinto the OFF-cycle (in spite of some decrease in the SAT dur-ing the OFF-cycle).
The “bumpless transfer” feature of the hydronic heat controlalgorithm essentially acts similar to a “memory” that holds thealgorithm output during the OFF-cycles. This “memory” isreset only on unit shutdown. The effect of this “memory” canbe observed on the action of the hot water valve. After unitstartup (during the first ON-cycle of the hydronic heat), thereis no “memorized” output value and the valve moves rela-tively slowly into a control position required to maintain theSAT setpoint. On subsequent ON cycles, the valve movesinto a control position much faster as dictated by the outputvalue stored in control algorithm “memory”.
COOLING LOCKOUT ON OAT
This is the Outside Air Temperature Setpoint that the controluses to lock out mechanical cooling when the OAT is belowthis setpoint. There is a one-degree hysteresis on each sideof the setpoint. Adjustable from 0°F to 100°F, the default is45°F.
The change to 0°F applies only to compressors # 1 and # 2when head pressure control is installed. Cooling Lockout onOAT may occur while the control is in an Economizer modeand there is a demand for compressors.
WATER COIL FREEZE STAT (FSI)
This option is used only on rooftop units with hydronic heat(Hydronic heat option is turned ON). When the FSI terminalsees 24 VAC, the control will open the Hot Water valve to100%. The control will continue to drive the valve to 100%until five minutes after the switch has closed. If the control isoperating the Fan, it will close the Economizer fully until thefreeze condition is over. If the fan is off and the RAT dropsbelow 40°F, the Hot Water Valve will turn on 100%. This con-trol sequence takes place regardless of the supply fan status(it is expected to be used/ needed mostly in situations whenthe supply fan is not running). A Hot Water Coil Freeze Alarmis generated. The alarm is written to the Error History Buffer.In networked applications, the alarm flag is readable by thenetwork.
After the valve override sequence described above is com-pleted, the valve will revert to normal operation and the alarmis automatically reset. The same sequence is repeated everytime the Hot Water Coil Freeze Switch opens (infinite retries).
CV OPERATION
The paragraphs below identify control modes of CV operationand provide an overview of control methods in all modes. Themodes include Occupied and Unoccupied Heating and Cool-ing, and differ depending on the method used to control zonetemperature (thermostat, or a space sensor). The heating vs.cooling modes are entered under control of the thermostat,or, in case of space sensor, control algorithm detecting zonecooling or heating demand. The "occupied" vs. "unoccupied"modes are controlled by an internal time clock. If a thermostatis connected in addition to the space sensor, it takes priorityover the space sensor.
THERMOSTAT OPERATION FOR COOLING WITH Y1, Y2, Y3 AND Y4 INPUTS
When connected to a thermostat, the Millennium Simplicitycontrol will apply internal rules to specific G, Y1, W1, etc.,requests for fan, cooling, or heating; other inputs such asSAT, economizer availability, etc., will be considered beforeacting on the thermostat request.
When stage outputs are de-energized, and when the fourtime delay settings in "Fan ON Delay for Heat, OFF for heat,ON for Cooling, and OFF for Cooling" are made, the Fan out-put will continue for the set time even if the G input becomesinactive along with Y1 and Y2. If G does not terminate, thecontroller will continue to operate the Fan.
A Minimum Run Time of up to ten minutes applies to all com-pressors. There is a built-in five-minute ASCD cycle when-ever a compressor is destaged. The minimum run time isnecessary to ensure that the oil in the refrigerant circuit circu-lates back to the compressor. A minimum ASCD delay of fiveminutes (nominal) applies any time compressor operation is
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started other than destaging. The actual minimum off timesfor individual compressors differ by 10 seconds in order toprevent compressors from turning on simultaneously duringcertain control mode transfers:
GROUPING COMPRESSORS INTO STAGES
In space sensor operation in CV mode: On two compressorunits, compressor one is first stage and compressor two issecond stage. On three compressor units, compressors oneand two are first stage and compressor three is secondstage. On four compressor units, compressors one and twoare first stage and compressors three and four are secondstage. There is a five-minute delay (cooling interstage delay)between stage-one and stage-two operation
Otherwise the system treats each compressor as a stage.
ECONOMIZER MODE
In CV cooling with a thermostat and when free cooling isavailable ("economizer suitable"), the SAT controlled by theeconomizer control algorithm (see section Economizer Oper-ation later in this manual) and the thermostat determines (by1st and 2nd stage calls) the active economizer SAT setpoint.When the thermostat is satisfied (Y1=OFF, Y2=OFF), thenthe unit either shuts down (in case G=OFF) after the specifiedsupply fan overrun time, or only the supply fan continues tooperate (in case G=ON). The operation of the thermostat's Gsignal is determined by the thermostat's fan mode switch
NOTE: During Economizer operation using "EconomizerFirst Stage Setpoint" for SAT control, one or morecompressors may be running in addition to econo-mizer damper partially, or fully open to provide freecooling. The number of compressors running willmainly depend on outdoor air temperature. There-fore, when the thermostat is satisfied and shutsdown the cooling, it may be turning off more thanone compressor (after compressor minimum runtime expires). This is acceptable and is notexpected to occur frequently. See the section onComfort Ventilation. If the outdoor air condition issuch that more than one compressor is needed inaddition to free cooling, the Economizer mode islikely to terminate and the unit will switch over tomechanical cooling only.
OPERATION FOR HEATING WITH W1, W2, AND W3 INPUTS
W1, W2, and W3 inputs are available on the Millennium Sim-plicity board.
SUPPLY FAN OFF DELAY
When the Wx thermostat signal is de-energized, the fan out-put will continue until the SAT drops below 100°F with a 5°Fdifferential to prevent fan cycling, i.e. the fan will go off whenthe SAT drops below 95°F. This control sequence will be ineffect even if G becomes inactive along with Wx. If G doesnot terminate, the Fan will continue to operate. The parame-ter “Turn Off Continuous Fan Operation When Starting Heat”can be set to the customer’s preference.
HEAT STAGE DELAYS
Three minute Minimum Run Time and two minutes minimumoff time applies to all heat stages.
THERMOSTAT OPERATION WITH HYDRONIC HEAT
The zone thermostat makes a selection between satisfiedstate (W1, W2, and W3 off), heating using a programmed"Hydronic Heat 1st Stage SAT Setpoint" (W1 is on, W2 is off),or heating using a programmed "Hydronic Heat 2nd StageSAT Setpoint" (both W1 and W2 are on). During heating, theSAT control to the selected SAT setpoint is performed using aPI algorithm.
SENSOR OPERATION
Typically, only a thermostat, or only a space sensor would beinstalled. However, there are cases where both could exist.One such case is servicing or troubleshooting the unit. A ser-vice person will typically hardwire the thermostat inputs tocheck the equipment operation even if the unit is using aspace sensor. The thermostat input will have priority over theSpace Sensor. A unit using a space sensor will switch to athermostat control strategy automatically if a thermostat inputis detected and switch back if the thermostat is no longerdetected.
TYPES OF SPACE SENSORS
No Sensor- The system will internally detect the presenceof space sensors.
Sensor with Unoccupied Override Button - This Sen-sor has a Thermistor and an Override button that shorts theSensor when pushed. If the Override button is pushed theunit will go into the Unoccupied Override mode for the Unoc-cupied Override Time (note that the control must not recog-nize the short as a sensor failure). Once the UnoccupiedOverride mode is initiated, it will continue until the pro-grammed Unoccupied Override Time Limit is reached.
TABLE 43: COMPRESSOR MINIMUM OFF TIMES
COMPRESSOR MIN. OFF TIME
#1 4 min. 40 sec
#2 4 min. 50 sec
#3 5 min. 00 sec
#4 5 min. 10 sec
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Sensor with Space Setpoint Adjust - This Sensor hasa slider potentiometer on it that represents (as a default) +/-3°F adjustment to the Space Setpoint. The Space SetpointOffset option. If the unit appears to be controlling at a higheror lower temperature than the setpoint, check the Space Set-point Adjust slider.
SUPPLY FAN CONTROL WHEN USING A ZONE SENSOR
In the Occupied mode, setting of the parameter "Fan ONmode with the Sensor Option" will determine if the SupplyFan is ON continuously, or is in "Auto" mode (i.e. cycles withthe heating/ cooling cycles). In Unoccupied mode, the fan isalways in the Auto mode.
SUPPLY FAN OFF DELAY
Uses minimum off time.
CONTROL OF COMPRESSORS WHEN USING A ZONE SENSOR
A Minimum run time of one to ten minutes [default = three]applies to all compressors. The minimum run time is neces-sary to ensure that the oil in the refrigerant circuit circulatesback to the compressor.
The Anti Short Cycle delay of five minutes OFF applies anytime compressor operation is terminated. Compressors areturned ON and OFF individually during CV operation with azone sensor, where the cooling control algorithm is imple-mented in the controller (rather than in a thermostat).
The stage groups are applicable only for control of compres-sors with external signals, such as from a thermostat.
There is a minimum 30 second delay between compressorswhen bringing on multiple compressors.
HEATING OPERATION WITH THE SENSOR OPTION
The space temperature is controlled to a programmed Unoc-cupied Heating Setpoint, or to a programmed Occupied Heat-ing Setpoint, as determined by the internal schedule and thestate of the Occupied Input (if this input is ON during a sched-uled unoccupied time, the unit goes to Occupied Overridemode).
The control will use as many as three stages of heat, depend-ing on what heat option is are installed.
A zone heating demand of -1.5°F will generate a request forfirst stage heat.
A zone heating demand of -2.0°F will generate a request forsecond stage heat.
A zone heating demand of -2.5°F will generate a request forthird stage heat. There is a three minute minimum off delayand a thirty second delay between stages.
When the zone temperature is -0.1°F, or less below the zonesetpoint for at least 1 minute, the transition to a satisfied stateoccurs, the heating stops and the supply fan either continuesrunning, or is turned off after SAT drops below 100°F. Thesupply fan control in the satisfied state and in the occupiedmode is determined by setting of the programmable parame-ter "Fan ON Mode with the Sensor Option". In the unoccupiedmode, the fan is always turned off when the zone is satisfied.
During heating, the SAT control to the selected SAT setpointis performed using a PI algorithm. Two minute Minimum RunTime and Anti Short Cycle delays applies to all heat stages.There is also a delay of at least one minute between turningon heating stages.
COOLING OPERATION WITH THE SENSOR OPTION
The control will operate as a two-stage unit.
On two compressor units, compressor one is first stage andcompressor two is second stage.
On three compressor units, compressors one and two arefirst stage and compressor three is second stage.
On four compressor units, compressors one and two are firststage and compressors three and four are second stage.
The control uses a minimum 30-second compressor delaybetween compressors when bringing on a stage with multiplecompressors.
A zone cooling demand 1.5° makes a call for first stage cool-ing.
A zone cooling demand 2.0° makes a call for second stagecooling.
If the unit has a demand greater than 1.5° but less than 2.0°,the control will turn on the first compressor of stage one andload a 5-minute timer. If after 5 minutes the Space tempera-ture is not moving toward the Setpoint, the control will turn onthe second compressor of stage one, if available, and wait 5minutes. The control will continue operating first stage untilthe Space temperature reaches the Setpoint and then it willturn off the stage one compressor. If after 5 minutes theSpace temperature is not moving toward the Setpoint, thecontrol will turn on the first compressor of stage two and wait5 minutes. The control will continue to turn on compressorsusing the 5-minute trending timer until the Space Tempera-ture begins to move toward the Setpoint. The control will turnoff all the second stage compressors with a 30-second delaybetween them when the demand reaches .5°F. The controlwill continue operating first stage until the Space temperaturereaches the Setpoint and then it will turn off the entire stageone compressor.
If the unit starts with a demand greater than 2.0°F, the controlwill stage up first stage and wait 5 minutes. The control will
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continue operating first stage until the Space temperaturereaches the Setpoint and then it will turn off all the stage onecompressors with a 30 second delay between them. If after 5minutes the Space temperature is not moving toward the Set-point the control will turn on the first compressor of stage twoand wait 5 minutes. The control will continue to turn on com-pressors until the Space Temperature begins to move towardthe Setpoint using the 5 minute trending method. The controlwill turn off all the second stage compressors when thedemand reaches .5°F with a 30 second delay between them.The control will continue operating first stage until the Spacetemperature reaches the Setpoint and then it will turn off theentire stage one using a 30 second delay between compres-sors if more than one is on.
VAV OPERATION
The paragraphs below identifies control modes of VAV opera-tion and provides an overview of control methods in allmodes. The modes include Occupied and Unoccupied Heat-ing and Cooling and differ depending on the method used tocontrol zone temperature (thermostat, or a space sensor).The heating vs. cooling modes are entered under control ofthe thermostat, or, in case of space sensor, by control algo-rithm detecting zone cooling, or heating demand. The "occu-pied" vs. "unoccupied" modes are controlled by the internal"Occupied/unoccupied" clock and the tables. If a thermostatis connected in addition to the space sensor, it takes priorityover the space sensor.
VAV OPERATION WITH A THERMOSTAT
The thermostat is placed in a selected, representative zone ofa VAV system and is used to reset SAT and cycle the VAVunit in cooling and to control heating. It is expected that thethermostat provide Yx outputs to control cooling and Wx out-put to control heating. The thermostat is expected to providean output to control occupied/unoccupied mode (a contactclosure that supplies in the occupied mode 24 VAC to the"OCC" Input).
As the thermostat has a capability to turn off the unit in occu-pied cooling mode, it is important to place it in a zone that isrepresentative of the remaining zones, or in a zone with thehighest occupied cooling demand.
The VAV zones are controlled by their own zone thermostatsto a temperature setpoint set independently of the setpointsof the "system control" thermostat; the setting of the occupiedcooling setpoint on the "system control" thermostat should atleast roughly correlate to the zone temperature setpoint. Forexample, the occupied cooling setpoint may be set at, orbelow the lowest zone temperature setpoint selectable on thezone thermostat. The setpoint setting should prevent a possi-bility of cooling turned off while other zone(s) in the systemstill have a cooling demand.
VAV OPERATION WITH A ZONE SENSOR
The Space Sensor is placed in a selected, representativezone of a VAV system. It is used to reset SAT in cooling andto control occupied heating based on comparison of zonetemperature to a programmed "VAV SAT Reset Setpoint".However, since the zone is controlled by its own zone ther-mostat to a temperature setpoint set independently of theVAV SAT Reset Setpoint, the setting of the VAV SAT ResetSetpoint should at least roughly correlate to the zone temper-ature setpoint.
For example, the VAV SAT Reset Setpoint may be set at, orbelow the lowest zone temperature setpoint selectable on thezone thermostat, in order to prevent a possibility of insuffi-cient cooling while other zone(s) in the system still have ahigh cooling demand. In unoccupied modes, the Space Sen-sor controls the unit based on unoccupied heating and cool-ing setpoints programmed in the unit controller.
The use of a Space Sensor is enabled by setting a program-mable parameter "VAV Operation with Thermostat". Whenthe Space Sensor is enabled, the control self-configures to aVAV operation with a Space Sensor if the sensor is available,and to a Return Air Temperature operation if the sensor is notavailable.
STANDALONE VAV OPERATION
In standalone operation the control unit receives an occu-pied/unoccupied command from an external source (such asa contact closure on the space sensor input). In occupiedcooling mode, it controls to the Low SAT setpoint. In unoccu-pied mode, the unit shuts down. In unoccupied mode, anexternal (network) command may be provided to start aMorning Warm-up cycle. The MWU cycle (if enabled) will alsostart upon a transition from Unoccupied to Occupied mode.
SUPPLY FAN OFF DELAY
Uses fan off delay.
OCCUPIED HEATING WITH A THERMOSTAT
When the unit enters the Occupied mode heating is startedby the thermostat turning ON its W1 output. In the Occupiedmode the thermostat will control to its occupied heating set-point. The thermostat's occupied heating setpoint should beset well below the zone thermostat's cooling setpoint, to rep-resent a heating setpoint typical for all system zones.
In VAV heating, full heating (all heating stages ON) occurswhen W1=ON, and no heating (all heating stages OFF)occurs when W1=OFF (note that in this case, the control willuse all available heating stages, regardless of setting of theprogrammable parameter "Heat Stages").
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The supply fan operates at 100% during heating. Dependingon the control setting, the fan will cycle On/Off with the W1output, or will remain On. On startup, the fan speed is rampedup, or the inlet vanes ramped open (a "soft start").
During occupied heating, the economizer damper remains atminimum position and all VAV boxes are fully open - box heatrelays are energized from Heat output of the controller. IfHydronic heat option is used, the Heat output of the controlleris also actuated during heating, the SAT is controlled to the2nd stage hydronic heat setpoint.
UNOCCUPIED HEATING WITH A THERMOSTAT
This operation is identical to the Occupied heating, exceptthe unit mode is in Unoccupied mode from the internal controlOccupied/Unoccupied table. The economizer damperremains fully closed in the unoccupied mode.
OCCUPIED COOLING WITH A THERMOSTAT
In this mode, the control uses a thermostat for cooling andfan operation. The thermostat's occupied cooling setpointshould be set below the zone thermostat's lowest adjustablecooling setpoint, to prevent a possibility of cooling turned offwhile other zone(s) in the system still have a cooling demand.
UNOCCUPIED COOLING WITH A THERMOSTAT
This operation is identical to the Occupied cooling, exceptwhen operating in the unoccupied mode the control is pro-grammed to control to its unoccupied cooling setpoint and theeconomizer damper min. position is set to 0%, however thedamper may modulate open if outdoor air can be used forfree cooling (economizer operation).
OCCUPIED HEATING WITH A SPACE SENSOR
The Space Sensor is placed in a selected, representativezone of the VAV system, in addition to the zone thermostat, orsensor used to control the zone's VAV box. The heating con-trol algorithm is enabled whenever the zone temperaturedrops 2°F or more below a programmed "VAV SAT Reset Set-point ", and disabled whenever the zone temperature is 1.5°F,or less below a programmed “VAV SAT Reset Setpoint". The"VAV SAT Reset Setpoint" would typically be set at, or belowthe lowest zone temperature setpoint selectable on the zonethermostat.
The supply fan is controlled to 100% during occupied heatingand cycles OFF when the heating control algorithm is satis-fied if there is no other call for the fan. On startup, the fanspeed is ramped up, or the inlet vanes ramped open (a "softstart").
When a call for heating (W1 or W2=ON) occurs, the econo-mizer damper remains at its programmed minimum positionand all VAV boxes go fully open - box heat relays are ener-gized from Heat output of the controller.
If Hydronic heat option is used, the Heat output of the control-ler is also actuated during heating and the SAT is controlledto the 2nd stage hydronic heat setpoint.
UNOCCUPIED HEATING WITH A SPACE SENSOR
When this mode is enabled and the unit enters the unoccu-pied mode, the unit will control heating by comparing thezone temperature to a programmed "Unoccupied HeatingSetpoint". The Space Sensor should be placed in a selected,representative zone of the VAV system, in addition to thezone thermostat, or sensor used to control the zone's VAVbox.
Full heating (all heating stages ON) occurs when the SpaceSensor algorithm requests heating, no heating (all heatingstages OFF) when the Space Sensor algorithm is satisfied(note that in this case, the control will use all available heat-ing stages, regardless of setting of the programmable param-eter "Heat Stages").
The supply fan is controlled to 100% during unoccupied heat-ing and cycles OFF when the Space Sensor control algorithmis satisfied if there is no other call for the fan. On startup, thefan speed is ramped up, or the inlet vanes ramped open (a"soft start").
During unoccupied heating, the economizer damper is fullyclosed and all VAV boxes go fully open - box heat relays areenergized from Heat output of the controller.
OCCUPIED COOLING WITH A SPACE SENSOR
This mode is entered when the control sees a Space Sensorsignal and enters the "occupied" mode. The Space Sensorrequests cooling (to a programmed High, or Low SAT set-point) whenever the zone temperature increases by a speci-fied amount above a programmed "VAV SAT Rest Setpoint".The Space Sensor should be placed in a selected, represen-tative zone of the VAV system, in addition to the zone thermo-stat, or sensor used to control the zone's VAV box.
The "VAV SAT Reset Setpoint" would typically be set at, orbelow the lowest zone temperature setpoint selectable on thezone thermostat, in order to prevent a possibility of insuffi-cient cooling while other zone(s) in the system still have ahigh cooling demand.
The supply fan, economizer, VAV boxes operate within theirnormal control rules.
UNOCCUPIED COOLING WITH A SPACE SENSOR
In this mode, the Space Sensor requests cooling based oncomparing the zone temperature to a programmed "Unoccu-pied Cooling Setpoint". When the Space Sensor control algo-rithm requests cooling, the unit runs cooling controlled to aprogrammed High SAT setpoint ("VAV Upper Cooling SATSetpoint"), or to a programmed Low SAT Setpoint ("VAVUpper Cooling SAT Setpoint"), as determined by comparison
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of zone temperature to a programmed "VAV SAT Reset Set-point". The "VAV SAT Reset Setpoint" would typically be setwell below the "Unoccupied Cooling Setpoint", causing theunoccupied cooling to typically use a Low SAT Setpoint.
There are two different SAT control algorithms, one usedwhen free cooling is available (economizer operation) and theother one for mechanical cooling only. These two SAT controlalgorithms are described in the “Occupied Cooling in Standa-lone Operation” section below. Since the economizer is notactive in Unoccupied mode, this will be restricted to mechani-cal cooling.
UNOCCUPIED HEATING IN STANDALONE OPERATION
Unoccupied heating is never used in standalone operation.
OCCUPIED COOLING IN STANDALONE OPERATION
The unit controls cooling to a programmed Low SAT setpoint("VAV Lower Cooling SAT Setpoint") during the occupiedmode. There are two different SAT control algorithms, oneused when free cooling is available (economizer operation)and the other one for mechanical cooling only. First, whenfree cooling is available ("economizer suitable"), the SAT con-trol algorithm is as described in the Economizer Operationsection later in this document, except the programmed Econ-omizer First Stage Setpoint and Economizer Second StageSetpoint are replaced by the programmed VAV Upper CoolingSAT Setpoint and VAV Lower Cooling SAT Setpoint.
When free cooling is not available, the SAT control is per-formed by the following control algorithm: Minimum compres-sor off times (ASCD) of 5 minutes and minimum on times ofone to ten minutes [default is three] are maintained and thecycling rate of the compressors will not exceed maximum 6cycles/hour. The SAT is controlled in a ±5°F band around theactive SAT setpoint. A compressor is allowed to turn on only ifthe current SAT minus the Predicted SAT Drop is more than5°F.
SUPPLY DUCT PRESSURE CONTROL ALGORITHM
The Supply Duct pressure is controlled to a specified setpoint(see paragraph Duct Pressure Setpoint, section Option Oper-ation earlier in this document). An appropriate closed loopcontrol PI algorithm is used to control the supply duct staticpressure by modulating Inlet Guide Vanes, or the supply fanVFD.
MORNING WARM UP / VAV OCCUPIED HEATING CONTROL ALGORITHM
STARTING MORNING WARM UP
Non-networked systems: The MWU (Morning Warm Up)option is enabled by setting the option parameter and estab-lishing a start and end Occupied time period in the control’sOccupied 1 weekly schedule.
MWU (Morning Warm Up) is initiated upon all transitions fromUnoccupied to Occupied mode. The system clock is used toidentify, for the Morning Warm Up, a 1 hour period beforeactual occupancy begins (also see Intelli-Start). If the MWUoption is disabled, the occupancies should be scheduled attheir regular time.
An Occupied Override signal will initiate a warm up of up totwo hours (the setpoint value of the Unoccupied OverrideTime Period). It is important to note that the unit is still operat-ing in an Unoccupied mode for the first hour after the occu-pied Override input is turned on. Reference the Weekly andHoliday Schedule, Tables 44 and 45.
MORNING WARM UP / VAV OCCUPIED HEATING FUNC-TION
Morning Warm Up controls the RAT to a preprogrammedMorning Warm Up RAT Setpoint. An appropriate closed loopcontrol algorithm is used to control heat stages to accomplishthis. The algorithm uses a dead band (i.e. control RATbetween the MWU RAT Setpoint and two degrees below thesetpoint).
FIGURE 30 - SAT CONTROL BAND
Stage Up If SAT is Above Setpoint
By + 5.00F, or More, For 5 Minutes
Active SAT Setpoint
Stage Down If SAT is Above Setpoint
By - 5.00F, or More, For 5 Minutes
- 5.00F
+ 5.00F
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Holiday Schedule
• If the Start Time is programmed to zero, the default is all day.
• The Number of Days will be programmed from 0-99.
• The Start Date is programmed by Month-Day-Year.
• When the Start Date is 00-00-0000, that Holiday is ignored.
• When the Time is 00:00, the Time is equal to 12:00 a.m., the beginning of the day.
Full heating (all stages) is ON when RAT drops 2°F below thesetpoint, heating is OFF when RAT is at, or above the set-point. (Note that in this case, the control will use all availableheating stages, regardless of setting of the programmableparameter "Heat Stages"). Before energizing heat for Morn-ing Warm Up the control will start the Fan and operate it for 5minutes. The Economizer will stay closed and the Fan willcontinue to run during the Morning Warm Up. The MorningWarm Up will terminate when the Occupied period begins.
If the RAT setpoint is achieved before the MWU periodexpires, Unoccupied cooling is permitted. If further heating isneeded during the Occupied period, it is controlled by a VAVOccupied Heating algorithm (if enabled and if a Space Sen-sor is used), or by a space thermostat.
The same algorithm is also used for VAV Occupied Heating(see also paragraph "VAV Occupied heating" in "Option Oper-ation" section earlier in this document). In this case, the VAVOccupied Heating control algorithm is activated under thecontrol of the Space Sensor (whenever the zone temperaturesensed by the Space Sensor drops 2°F or more below a pro-grammed "VAV SAT Reset Setpoint"). Once activated, theOccupied Heating control algorithm controls RAT betweenthe MWU RAT Setpoint and two degrees below the setpointand cycles the fan the same way as the MWU algorithm.
The specified Max Morning Warm Up Time is not used to limitthe duration of VAV Occupied Heating. During heating forMorning Warm Up, or for VAV Occupied heating function, theVAV boxes controls will receive an override signal to open theVAV box damper. This is accomplished by wiring the VAVheat relay for the VAV boxes to open, and energizing it fromHeat output of the controller. Note that as the first stage ofheat cycles on / off, the VAV box heat relay will cycle with it.
UNOCCUPIED VAV HEATING / COOLING CONTROL ALGORITHM WITH A SPACE SENSOR
In the unoccupied mode, the Space Sensor will compare thetemperature in a selected VAV zone to the programmedUnoccupied Heating and Cooling setpoints and request heat-ing or cooling using the following control algorithm:
OCCUPIED VAV HEATING / COOLING CONTROL ALGO-RITHM WITH A SPACE SENSOR
In the occupied mode, the control will compare the tempera-ture in a selected VAV zone to the programmed "VAV SATReset Setpoint" and request heating or cooling using the fol-lowing control algorithm: The transition from cooling to occu-pied heating occurs at 2°F below the "VAV SAT ResetSetpoint". There is no "satisfied", or "idle" state of the unitbetween cooling and occupied heating.
The above algorithm only requests occupied cooling andselects a SAT occupied cooling setpoint, or requests occupiedheating at a programmed "Morning Warm Up RAT Setpoint".
Once requested by this Space Sensor algorithm, the coolingis controlled by the SAT control algorithm described in para-graph "SAT Control Algorithm in VAV Cooling" earlier in this
Holiday Number Start Month Start Dayof Month Start Time Number
of Days
Holiday 1 00 00 00:00 00
Holiday 2 00 00 00:00 00
Holiday 3 00 00 00:00 00
Holiday 4 00 00 00:00 00
Holiday 5 00 00 00:00 00
Holiday 6 00 00 00:00 00
Holiday 7 00 00 00:00 00
Holiday 8 00 00 00:00 00
Holiday 9 00 00 00:00 00
Holiday 10 00 00 00:00 00
Holiday 11 00 00 00:00 00
Holiday 12 00 00 00:00 00
Holiday 13 00 00 00:00 00
Holiday 14 00 00 00:00 00
Holiday 15 00 00 00:00 00
Holiday 16 00 00 00:00 00
Holiday 17 00 00 00:00 00
Holiday 18 00 00 00:00 00
Holiday 19 00 00 00:00 00
Holiday 20 00 00 00:00 00
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section [not to be found by that name...]. Once requested bythis Space Sensor algorithm, the occupied heating is con-trolled by the RAT control algorithm described in paragraph"Morning Warm Up / VAV Occupied Heating Control Algo-rithm" earlier in this section.
CONTROLLING EXCESSIVE SAT (SUPPLY AIR TEMPERATURE)
This is required in cooling operation in order to prevent a dan-ger of "slugging" and damage to the DX compressors. Roof-top units do not use accumulators on compressor intake, andliquid refrigerant could enter the intake of a compressor incase of a low heat transfer on the evaporator coil. In heatingoperation, the Excessive SAT control is not used.
SAT CONTROL CONFIGURATION
SAT control for cooling is configurable to enable or disable(on/off). The default setting for cooling is ON. The user is notnormally expected to turn this mode OFF, but the possibility ofturning it OFF is provided mainly for troubleshooting purposes.
SAT CONTROL FOR COOLING
This control has priority over any other zone temperature orSAT control and is used at all times, during CV as well asVAV operation. The Excessive SAT Control state is enteredany time the SAT drops below the trip point of a compressor(as the trip points are programmed in an ascendingsequence, the compressor that trips will always be the high-est- numbered one).
While in this state, the control will continue monitoring theSAT and turning off compressors any time the SAT dropsbelow the respective trip point. There is a 2 minute time delaybetween compressor trips in cases when the SAT dropsbelow trip points of multiple compressors. This assures thatmultiple compressors will not be turned off simultaneously.
ECONOMIZER LOADING OPERATION DURING AN EXCESSIVE SAT FOR COOLING:
CV ECONOMIZER OPERATION
Economizer dampers allow mixing of outdoor and return air.The dampers are coupled and controlled with a single actua-tor such that when the Outdoor Air damper is fully closed, theReturn Air damper is fully open (and vice versa). The positionof the Economizer dampers is controlled based on:
• Energy considerations (“free cooling”)• Ventilation considerations (minimum Outdoor Air damper
position and Demand Ventilation)• Space static pressure considerations (minimum Outdoor
Air damper position).
Economizer dampers are also controlled in certain situationsto perform ”economizer loading” - which minimizes SAT tem-perature swings resulting from turning cooling, or heatingstages on / off. This function is separate from normal econo-mizer operation, and is separately described at the end of thissection.
When is the Economizer operation used?
If the rooftop unit is equipped with an economizer (and thatoption is selected), and free cooling is available (“economizersuitable”), then the Economizer Operation as specified in thissection will be used in the following operation modes:
CV cooling with thermostat, or zone temperature sensor con-trol (note that in the zone sensor mode, the compressor stag-ing algorithm defined in this Economizer section will replacethe zone sensor based control described in Sensor Operationin CV Operation section, earlier in this document).
Minimum Ventilation Position setting
The minimum position setting represents the minimum open-ing of the outdoor air damper (% open). This setting will bemaintained any time the unit is in Occupied mode. The mini-mum position setting will be determined by an “EconomizerMin Position” programmable parameter set by a Palm Pilot.The minimum position setting will be ignored during the Unoc-cupied mode. During the Unoccupied mode, the minimumposition is 0% (the Economizer may not remain closed duringthe Unoccupied mode, in case the temperature control to anunoccupied setpoint can use Outside Air for free cooling).
Minimum Position during Heating and Occupied Mode
During heating while in Occupied mode, the economizer willbe at its programmed minimum position.
Minimum Position during Cooling and Occupied Mode
During cooling while in Occupied Mode, the economizer maybe at its programmed minimum or may be modulatedbetween its minimum position and 100% open position by theeconomizer control.
SAT SETPOINTS USED DURING COOLING WITH ECONOMIZER OPERATION
As long as the Economizer Operation is enabled and “freecooling” is available, the economizer will be controlled (with,or without any compressors running) to maintain the followingSAT setpoints: In CV cooling mode:
• With a call for first stage cooling, a programmed Econo-mizer First Stage Setpoint. This setpoint is programma-ble in the range of 40°F to 65°F, default setting is 55°F.
• With a call for second stage cooling, a programmed Econ-omizer Second Stage Setpoint. This setpoint is program-mable in the range of 40°F to 65°F, default setting is 50°F.
Criteria for Economizer Suitable decision Sensor avail-ability:
There are three different methods of deciding whether theeconomizer is suitable:
• Differential enthalpy (highest preference from energy viewpoint)
The choice of a method with highest preference is automatic(“self-configuration”) based on availability of appropriate sen-sors. If a sensor fails/ goes unreliable, a fault is indicated and,again, the next highest preference method will be automati-cally selected (“fault tolerance”).
There are two ON/OFF programmable parameters related tothe choice of an economizer method:
• “OAH Sensor Enable”• “RAH Sensor Enable”
These parameters are set to reflect the installed sensors thatcan be used by the “self-configuration” feature and controlsensor failure alarms.
The OAH sensor, if available, allows use of Outside Enthalpymethod for deciding on free cooling availability.
The RAH sensor, if available in addition to the OAH sensor,allows use of Differential Enthalpy method for deciding onfree cooling availability.
See paragraphs OAH Sensor Enable and RAH SensorEnable in Settable Parameters, Table 52 in this document.
If the selected method is using an enthalpy, the enthalpy iscalculated in the controller from sensed temperature andhumidity of the respective air stream.
Differential Enthalpy Method: is set by parameter and usedonly when sensors for Outdoor Air temperature, Outdoor Airhumidity, Return Air temperature and Return Air humidity areall installed and reliable.
Outside Enthalpy Method: will be configured by setting ONthe parameter for the Outdoor Humidity Sensor [OAH], andwill be the default if the unit defined as Differential Enthalpycannot read the Return Air Humidity sensor.
Outside Temperature Method: will be self-configured andused only when differential enthalpy or outside enthalpymethods are not available, and sensor for Outside Air tem-perature is installed and reliable.
Economizer is suitable when OAT is less than SAT setpoint +10°F. Use a 2°F differential on both sides of this limit. As theSAT setpoint value, use only one of the programmed 1st or2nd stage economizer setpoints (depending on what coolingstage is called), not any “transient” setpoints that may betemporarily used during process of staging. Note that this ruledoes not reflect any consideration of geographical locationand weather conditions, but rather reflects the averageexpected SAT temperature drop obtained from DX coolingstages, i.e. the highest outdoor air temperature that the DXcooling can still reliably reduce to the SAT setpoint
Outside Enthalpy Method: Economizer is suitable when OAEnthalpy is less than Outside Enthalpy number AND OAT isless than SAT setpoint + 10°F: Use a 2°F and 1 BTU/LB dif-ferentials respectively on both sides of these limits. TheEnthalpy number is a programmed parameter (range 22-40BTU/LB, default 30 BTU/LB. The Enthalpy Number can beviewed as the maximum outdoor air enthalpy with which the
outside air can still be considered suitable for DX cooling, or,in comparison to the Differential Enthalpy Method describedbelow, as a “best guess” on actual return air enthalpy (whichin this method is not being sensed). The temperature limitreflects the average expected SAT temperature dropobtained from DX cooling stages.
Differential Enthalpy Method: Economizer is suitable whenOA Enthalpy is less than the RA Enthalpy AND OAT is lessthan SAT setpoint plus 10°F (+/- 2° and 1 BTU/LB): Use a 2°Fand 1 BTU/LB differentials respectively on both sides of theselimits. This is similar to the Outside Enthalpy method, exceptinstead of a programmed Enthalpy Number, an actuallysensed return air enthalpy is used.
SAT Control with Economizer
If the economizer is “suitable” (free cooling is available) andcooling is required (the unit is not in satisfied state), the algo-rithm will be active and modulate economizer position inorder to control SAT to the active SAT setpoint. If the econo-mizer is not suitable, the algorithm is deactivated and theeconomizer is placed at its programmed minimum position.The economizer control algorithm will typically be cycledON/OFF several times an hour (will be activated and deacti-vated) under control of a zone thermostat, or a zone sensor.A zone control algorithm will activate the economizer algo-rithm when cooling is required, and will switch between Econ-omizer 1st and 2nd stage SAT setpoints, and will deactivatethe economizer algorithm when the zone is satisfied.
The PI algorithm is direct acting. This economizer controlalgorithm is always active during economizer operation (aslong as economizer is “suitable”) and will control SAT to anactive (1st or 2nd stage) Economizer setpoint. This meansthat this control loop not only modulates the Outside Airdamper open to add free cooling and decrease mixed airtemperature to maintain SAT at setpoint, but, when DX cool-ing is running, also may modulate the Outside Air damperclosed to increase mixed air temperature (use more returnair) and thus add load on the DX coil to maintain SAT at set-point (“economizer loading”). This represents a trade-offbetween energy and compressor cycling.
Control of compressors with Economizer
Compressors are turned ON / OFF individually, regardless ofgrouping them into “stages”. The stage groups are used onlyfor control of compressors with external signals, such as froma thermostat.
Turning ON of compressor #1:
Never operate compression if the Economizer can maintainthe SAT setpoint with free cooling. If no compressors are on,and the economizer controller is saturated High (i.e. theeconomizer is 100% open and can no longer maintain theSAT setpoint by just free cooling),
• Temporarily override SAT setpoint to increase it by 5°F• When the SAT is within 0.5°F of this temporary setpoint,
turn on compressor #1• Resume SAT control at active setpoint
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This is done in order to read and store the SAT temperaturedifferential (drop) due to turning on compressor #1, whileassuring that turning it on will not drop the SAT below com-pressor #1 trip point (where the Excessive SAT control wouldturn it off again). The same staging sequence is used for theremaining compressors (see below). Note that the standard 5minute delay before monitoring SAT after a compressor isturned on, or off, applies here also.
Turning on compressors #2 through #4:
If the economizer controller is saturated High (i.e. the econo-mizer is 100% open while one or more compressors are run-ning and the control can no longer maintain the active SATsetpoint requested by the zone control),
• Temporarily override SAT setpoint to increase it by 5°F• When the SAT is within 0.5°F of this temporary setpoint,
turn on the next compressor• Resume SAT control at active setpoint
NOTE: The pre-staging SAT increase must be done ”proactively”, by a temporary override of the active SATsetpoint, rather than by allowing the SAT to “drift” upby 5°F out of control. The time it would take for theSAT to “drift” up could be fairly long, mostly depen-dent on the outdoor air temperature change and inthe meantime, the zone temperature may go out ofcontrol as the additional needed cooling is not beingdelivered.
NOTE: The standard 5 minute delay before monitoring SATafter a compressor is turned on, or off, and thechecking against a stored, predicted SAT tempera-ture drop, applies here also.
Turning compressors off:
A highest numbered running compressor is turned off whenthe economizer controller is saturated Low.
This method of turning compressor off is considered betterthan using the Excessive SAT Control - turning a compressorOFF only if SAT reaches its specified trip point. If that methodwas used and the Excessive SAT Control was not selected,there would be no means for turning compressors off.
NOTE: The compressors also will be turned off in CV sys-tems with zone thermostat, or zone sensor tempera-ture control, when the zone temperature control issatisfied. For the case of zone sensor, the compres-sor destaging is described in section “CV Opera-tion”, paragraph “Control Algorithm for Cooling withthe Sensor Option, with Economizer”. For the caseof zone thermostat, the compressor destaging isdescribed in section “CV Operation”, paragraph“Thermostat Operation for Cooling with Y1 and Y2inputs”, subparagraph “Economizer Mode”.
Compressor control when exiting Cooling Lockout onOAT:
A situation may arise when in Economizer Mode and one ormore compressors are required in addition to full availablefree cooling in order to maintain the SAT setpoint, but CoolingLockout on OAT prevents the compressors use. This situationmay arise when the SAT setpoint is set very close to, or evenbelow the temperature set for Cooling Lockout on OAT - a rel-atively unusual case. If the OAT then increases above thelockout setting while the call for several compressors exists,the compressors will turn on with a delay between compres-sors.
Economizer Loading Option
This is a programmable option. The user has the ability toturn this function off. It is automatically disabled if the unitdoes not use an economizer. The on/off programming choiceis common to both cooling and heating. The default setting isON. This programmable “Economizer Loading” function isused only outside the normal Economizer operation.
During the Economizer operation, the “Loading” function isalways used and is an integral part of the Economizer controlalgorithm.
Economizer loading option in cooling:
In cooling, this function causes changes in mixed air temper-ature (as modulated by the economizer dampers) in order tochange SAT and keep it at SAT setpoint when only compres-sor #1 is running. This makes a trade-off between energy andcompressor cycling and minimizes cycling of compressor #1.The loading is done by the same type of control algorithm (PI)as used in the normal Economizer operation.
The algorithm will be activated to do this function in followingconditions:
• Economizer is “not suitable” (i.e. we are not in a normal Economizer mode)
• The programmable option “Economizer Loading to Con-trol SAT” is ON
• Only compressor #1 is running
The PI control algorithm in this case has a capability to auto-matically change from direct to reverse acting in response todifference between OAT and RAT. When OAT is less thanRAT, the algorithm is direct acting, for OAT & RAT, the algo-rithm changes to reverse acting. This way, the ”loading” of theDX coil is correctly done with return, or outdoor air, as appro-priate, and there is no need to activate this “loading” functiononly at higher outdoor air temperatures (e.g. OAT > 60°F).
The algorithm controls SAT to its specified setpoint (whenapplicable, e.g. in VAV operation), or, in control modes whereno SAT setpoint is specified (such as in Excessive SAT con-trol state in cooling), to a fixed temperature deadband of 50°Fto 55°F.
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NOTE: As opposed to the PI algorithm used in economizercontrol, the PI algorithm used here for economizerloading function does not need to utilize the Highsaturation state for any additional control functions.Therefore no complications arise when switchingbetween direct and reverse acting modes.
Economizer loading option in heating:
In heating, this function uses additional outside air (as modu-lated by the economizer dampers) in order to decrease SATwhen only the first stage of heating is running and keep theSAT below the programmed ”Economizer Loading Setpoint inHeating”. This prevents heating stage from cycling on itsinternal temperature limit safety switch (which is typically setabout 10°F above the Economizer Loading Setpoint). A needfor economizer loading arises in Communicating Zoning Sys-tem applications (“VVT” systems) using supply air bypasswhen heating load in the zones is low and a large amount ofhot supply air is bypassed back into return and mixed air tem-perature is very high. Economizer loading may also beneeded when supply air flow across the heat exchanger islower than expected (e.g. wrong setting of fan speed,plugged air filters). A secondary benefit of economizer load-ing is an improvement in comfort as the supply air tempera-ture is more stable and cycling of the unit is minimized.
The economizer loading option in heating is not implementedin VAV applications as these do not use supply air bypassand (in case of using a zone thermostat) run all heatingstages during heating (economizer loading applies to only the1st heating stage).
The economizer loading minimizes cycling of heating stage#1 and makes a trade-off between energy and the benefitsdescribed above.
The Economizer Loading in heating option requires a SATsensor that can sense SAT in heating mode (a sensor placeddownstream of the heating stages). Such a sensor is pro-vided only as a field-installed accessory, on units equippedwith heating stages. The SAT sensor that is factory-installedcan be used for cooling mode only. If a field-installed sensoris added, it will replace the factory-installed one and will thenbe usable for both heating and cooling modes.
The loading is done by the similar control algorithm as usedin the normal economizer operation. The algorithm is acti-vated to do this function in following conditions:
• Heating mode• The programmable option “Economizer Loading to Con-
trol SAT” is ON• Only heating stage #1 is running
The PI control algorithm in this case has a capability to auto-matically change from direct to reverse acting in response todifference between OAT and RAT. When OAT is less thanRAT the algorithm is direct acting, when OAT is greater thanRAT the algorithm is reverse acting.
This way, the “loading” of the heating stage is correctly donewith return, or outdoor air, as appropriate, and there is noneed to activate this ”loading” function only in some specificrange of outdoor air temperatures (e.g. OAT > programmedfirst heating stage trip point minus 50°F).
NOTE: In this case, the provision for direct vs. reverse act-ing switching is not essential feature of the controlalgorithm and the algorithm could be implementedas direct acting only in order to simplify implementa-tion and save code space. The situation when econ-omizer loading in heating is required while OATgreater than RAT is unlikely and if it should occur,the difference between OAT and RAT is negligible incomparison to the SAT control setpoint. The Econo-mizer Loading function in heating controls SAT to afixed temperature deadband of programmed “Econ-omizer Loading Setpoint in Heating” and 5°F belowthis setpoint (the setpoint is programmable between100°F - 195°F, default is 160°F).
In units that use hydronic heat, the Economizer Loading func-tion may be enabled in order to be used for cooling (the on/offprogramming choice for this function is common to both cool-ing and heating). In this case, it is important to ensure that theprogrammed value of the “Economizer Loading Setpoint inHeating” is set higher than the value of “Hydronic Heat FirstStage Setpoint”. That, in normal conditions, assures that theEconomizer Loading function in heating is effectively disabledand the economizer is closed to its minimum position duringheating.
VAV
When is the Economizer operation used? If the rooftop unit isequipped with an economizer and free cooling is availablethen the Economizer Operation as specified in this section isused in the following operation modes:
VAV cooling (except the programmed Economizer First StageSetpoint and Economizer Second Stage Setpoint arereplaced by the programmed VAV Upper Cooling SAT Set-point and VAV Lower Cooling SAT Setpoint)
DEMAND VENTILATION
Demand Ventilation Operation control mode is self-configur-ing for the use of an Indoor Air Quality (IAQ) sensor - it willautomatically detect that an IAQ sensor is connected and useit any time the IAQ sensor input indicates an IAQ level of 200ppm, or higher.
NOTE: Due to the self-configuration operation, an error dueto IAQ sensor failure can be indicated only in casethe IAQ sensor fails during normal controller opera-tion. If the IAQ sensor fails, or is removed / discon-nected during a power-off condition (e.g. duringservicing of the unit while the control is not pow-ered), the control will, on power up, self configurewithout the IAQ sensor and no error indication isprovided.
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When the IAQ sensor is detected as available, the control willuse the Demand Ventilation Setpoint to control the IAQ levelsin the building by modulating the Economizer more open.
The Demand Ventilation will operate in units equipped with anEconomizer (Economizer option is turned ON) any time thecontrol is in Occupied mode. The Demand Ventilation Opera-tion is applicable in heating, or cooling mode, and will modu-late the Economizer damper more open, if necessary, from itsprogrammed minimum position (in heating, or in coolingwhen economizer is not "suitable"), or from its modulatedposition determined as defined in the Economizer Operationsection (in cooling, when economizer is "suitable").
An appropriate control algorithm is used to accomplish thiscontrol. Preferably, this algorithm is a "step-and-wait" type,with the step size calculated as a function of offset betweenthe Demand Ventilation Setpoint and the current IAQ level,and with a fixed "wait", or sampling time. This algorithm isactivated whenever the IAQ level exceeds the setpoint andwill override the economizer position more open, as needed,up to a pre programmed Maximum Economizer Position forDemand Ventilation. The algorithm is deactivated, and theprevious, normal mode of economizer position controlresumed when the IAQ level becomes 50 ppm lower than thesetpoint.
The programmed "Maximum Economizer Position forDemand Ventilation" is used to minimize the possibility thatthe Demand Ventilation may open the Economizer dampertoo much, such that at fairly high OA temperatures, evencombined cooling output of all compressors would not pro-vide sufficient cooling (as a rule of thumb, all compressorscombined achieve approx. 20°F SAT decrease). Similarly, atfairly low OA temperatures, the combined output of all heat-ing stages may not be able to provide sufficient heating. ThisEconomizer max. position limit is simpler to implement than aclosed loop SAT low-limit control that would operate with aprogrammed high-limit for cooling and a programmed lowlimit for heating.
NOTE: An added measure of protection against excessiveSAT during Demand Ventilation Operation is pro-vided by Supply Air Alarm Setpoint for Cooling andSupply Air Alarm Setpoint for Heating, and the con-trol function associated with these setpoints (seethe respective paragraphs in the Option Operationsection earlier in this document).
EXHAUST OPERATION
Building static pressure is controlled through one of threemethods. One method incorporates a fixed speed fan that iscontrolled from the position of the Economizer dampers. Asecond method uses proportional control that modulates theexhaust damper and operates the fan based on the positionof the dampers. A third method uses a variable speed fancontrol that looks at building static pressure. All are depen-dent on the supply fan being ON.
TWO-POSITION CONTROL (NON MODULATING POWER EXHAUST)
This mode is a fixed speed, ON/OFF Power exhaust fan, witha barometric relief damper, controlled from position of theEconomizer damper. The Power Exhaust and the Econo-mizer options must be ON.
This mode is a fixed speed, ON/OFF Power exhaust fan, witha barometric relief damper, controlled from position of theEconomizer damper. The Power Exhaust and the Econo-mizer options must be ON.
The Exhaust Fan (EF) is controlled with a relay output of thecontroller and "slaved" to the Economizer damper positionvalue.
The EF relay is energized whenever the Supply Fan is run-ning and the Economizer (Outdoor Air Damper) is com-manded open more than the programmed EconomizerDamper Position for Exhaust Fan to turn ON.
The EF will be de-energized when supply fan is off or whenthe OAD opening is less than the EF Turn OFF set point or10% open, whichever is greater. Default Setpoint settings forthe EF to turn ON at Economizer 60% open, turn OFF atEconomizer 20% open. The EF has a minimum run time of10 seconds and a minimum off time of 60 seconds.
PROPORTIONAL CONTROL (FAN WITH MODULATING EXHAUST AIR DAMPER (EAD) CONTROLLED FROM BUILDING STATIC PRESSURE)
In this mode the Power Exhaust, Modulating Exhaust, Econo-mizer and Building Pressure Sensor Enable options must beON and the Supply Fan must be running. The EAD actuatoris modulated to maintain building static pressure to a pro-grammed Building Pressure Setpoint. An appropriate closedloop control algorithm is used to accomplish this control.
The control will modulate from full closed to full open over a2-minute period. The proportional band is from 0.015 in w.g.(3.7 Pa) below the Building Pressure Setpoint to 0.015-in.w.g. (3.7 Pa) above the set point.
The control algorithm is disabled and exhaust air dampercommanded closed whenever the supply fan is off. Buildingpressure is sensed with a -0.250 to +0.250 in. w.g. (-31 to +31 Pa) 0 - 5V output pressure differential transducer. Thetransducer senses the building pressure as referenced to anappropriate reference point outside the building. Transduceroutput signal is filtered (e.g. time averaged over 15 secondperiod) to compensate for wind gusts.
The Exhaust Fan (EF) is controlled with a relay output of thecontroller and "slaved" to the Exhaust Air Damper position.The EF relay is energized whenever the Supply fan is runningand the EAD is open more than the programmed ExhaustDamper Position for Exhaust Fan to turn ON. The EF relay is
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de-energized when Supply fan is off or when the EAD open-ing is less than the programmed Exhaust Damper Position forExhaust Fan to turn OFF, or 10% open, whichever is greater.The minimum run time is 10 seconds and minimum off time is60 seconds. (Non-adjustable). Default Setpoint settings arefor the EF to turn ON at Exhaust Air Damper 80% open andturn OFF at Exhaust Air Damper 20% open. The BuildingPressure Setpoint default is 0.100" w.g.
PROPORTIONAL CONTROL WITH VFD FAN
This is similar to the proportional EAD option, except that thedamper signal is used to control motor speed using a variablefrequency drive.
TWO-POSITION CONTROL (POWER EXHAUST WITH BAROMETRIC RELIEF, CONTROLLED FROM BUILDING STATIC PRESSURE)
In this mode the Power Exhaust, Economizer and BuildingPressure Sensor Enable options must be ON. The ExhaustFan (EF) is controlled with a relay output of the controller. TheEF relay is energized whenever Supply fan is running andbuilding static pressure is above a programmed Building Pres-sure Setpoint + 0.015 “ w.g. (3.7 Pa). The EF relay is de-ener-gized when supply fan is off, or when building static pressure isless than a programmed Building Pressure Setpoint - 0.015”w.g. (3.7 Pa). The minimum run time is 10 seconds and mini-mum off time 60 seconds (Non-adjustable). With this type ofcontrol, the Power Exhaust fan cycle, as its operation directlyinfluences the building static pressure that controls it. Thecycling rate is limited by these minimum ON and OFF time set-tings. The Building Pressure Setpoint default is 0.100" w.g.
ERV
During operation, the ERV [Energy Recovery Ventilation]exhausts return air from the building, but it is not a 'powerexhaust'; the system is NOT controlled by building pressure.If building pressure control is required, it must be done byother means - standalone power exhaust, or power exhaustin another unit serving the same space.
The ERV forces high volume fresh air exchange, but capturesthe heat energy of the outgoing air and transfers it to theincoming stream. ERV blower operation is NOT modulated toa pressure setting; there is no building pressure transducer inthe system. The unit's supply fan pulls air through the inletside of the ERV wheel.
Ducting and demand will vary from one installation to another.Adjusting the unit to achieve fresh air requirements and'exhaust-neutral' air flow must be done by the installer, usingthe manual dampers in the unit.
If the unit is variable air volume, the ERV exhaust motors willbe controlled by a variable frequency drive in the Millennium,using the same signal voltage that modulates supply air,either by inlet guide vane or variable frequency drive. This isdone to keep supply and exhaust air flow in balance.
The exhaust blowers in the ERV use the power and controlhardware that otherwise would run the power exhaust. TheEXH output from the Simplicity runs the ERV motors; if theunit is VAV, the EXD+/- terminals provide the ERV variablefrequency drive speed signal.
Where a unit has both ERV and an economizer, the ERV willstop wheel rotation when the economizer dampers open farenough to trigger the user-settable switch in the damper actu-ator. If free cooling is available, the heat exchange wheeldoes not need to rotate; the wheel will cycle on schedule tokeep the air passages blown clean.
Also refer to the ERV Installation Instructions packaged withthe ERV.
SCHEDULING OPERATION
The Millennium Simplicity refers to its clock and internal cal-endar.
COMPRESSOR STATUS MONITORING
Compressor status is monitored using three separate 24 VACcircuits.
Monitoring: low pressure, high pressure, and compressormodules.
The corresponding compressor status is monitored. If any ofthe three safeties is in error, the trip is noted in the alarm his-tory and the next available compressor will be used ifneeded.
The Low Refrigerant Pressure Switch is Normally Open,pressure closed. When the compressor is off and refrigerantpressure equalized, the switch under normal conditions isexpected to be closed. However, in cold ambient operation, itmay stay open and close only after the compressor starts up.
If an error is detected for a compressor, that compressor’soutput is turned off (note that the controller executes theapplication code once every 32ms, with a 30 second startupdelay and 5 second minimum error time on low pressure. Thecontrol then declares a "Compressor Locked Out on [ ] Trip"alarm. The alarm is written to the Error History Buffer.
NOTE: The compressor lockout works as an override of theoutput of the staging algorithm for cooling control.For example, the cooling control may ask for com-pressor #2 that is locked out, and as this requestdoes not generate additional cooling, will ask for thenext compressor, #3, to satisfy the cooling demand.If, after 10 minutes, the requested compressor #2does start up, the cooling output now may beexceeding demand, and the control will turn offcompressor #3, etc.
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TABLE 46: ALARM DEFAULT CODES
Code Cause
1 Compressor number one locked out on High Pressure Control
2 Compressor number two locked out on High Pressure Control
3 Compressor number three locked out on High Pressure Control
4 Compressor number four locked out on High Pressure Control
5 Compressor number one locked out on Low Pressure Control
6 Compressor number two locked out on Low Pressure Control
7 Compressor number three locked out on Low Pressure Control
8 Compressor number four locked out on Low Pressure Control
9 Compressor number one locked out on excessive motor trips
10 Compressor number two locked out on excessive motor trips
11 Compressor number three locked out on excessive motor trips
12 Compressor number four locked out on excessive motor trips
13 First stage heating is locked out due to excessive Limit Switch Trips
14 Second stage heating is locked out due to excessive Limit Switch Trips
15 Third stage heating is locked out due to excessive Limit Switch Trips
16First stage of heating is locked out because the ignition board failed to turn on the gas valve after 5 minutes of operation or the gas valve has voltage on it and the control is not calling for this stage of heating
17Second stage of heating is locked out because the ignition board failed to turn on the gas valve after 5 minutes of operation or the gas valve has voltage on it and the control is not calling for this stage of heating
18Third stage of heating is locked out because the ignition board failed to turn on the gas valve after 5 minutes of operation or the gas valve has voltage on it and the control is not calling for this stage of heating
19 Space Temperature Sensor has failed open or shorted
20 Supply Air Temperature Sensor has failed open or shorted
21 Return Air Temperature Sensor has failed open or shorted
22 Outside Air Temperature Sensor has failed open or shorted
23 Dirty Filter Switch has tripped
24 Unit has locked out on the APS. Air Pressure Switch.
25 The APS is stuck closed.
26 A microelectronics failure has occurred and the control is operating on defaults
27 A microelectronics failure has occurred and the control is down due to a fatal fault.
28 The control is locked out due to Fan Overload Trips
29 Outside Humidity Sensor is out of Range
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30 Return Air Humidity Sensor is out of Range
31 IAQ Sensor is out of Range
32 Real Time Clock cannot be read and has a hardware failure
33 Space Temperature Offset is greater than 20K Ohms
34 CV/VAV input is out of range and the unit is locked out
35 Unit is locked out due to low voltage on the 24 VAC supply
36 Smoke Purge
37 Duct Static has Exceeded Limit
38 Supply Air Temperature Cooling
39 Supply Air Temperature Heating
40 Economizer Minimum Position
41 Space Temperature
TABLE 46: ALARM DEFAULT CODES (Continued)
Code Cause
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TROUBLESHOOTING A MILLENNIUM SIM-PLICITY CONTROL
STATUS LED CHART
The Status LED mounted on the controller PC board will flashspecified flash patterns to indicate rooftop unit status. SeeTable 47.
Flash Times:
• Off: The power is Off, or the control has failed• On 250ms Off 250ms: The Control is operating but an
Alarm is active.• (The Number of the Alarm will be displayed on the char-
acter display.)• On one second, Off one second: This will be the "Heat
Beat"; The Control is operating normally with no Alarms.• On Steady: The Control has Failed• Two flashes On, then two seconds Off: The Control is
waiting for an ASCD Timer to finish.
FAILURE MODES AND DEFAULT OPERATION
ERROR HISTORIES
Error data storage: The control will store the latest five errorsin a FIFO manner in EEPROM, for later display. It will storestatus information ("active" vs. "inactive") for all error types toprovide for situations when an error snapshot is triggered bymultiple errors occurring at the same time. As the control col-lects errors, it will overwrite the oldest error after the historybuffer becomes full.
Errors that are entered into the error history buffer:
• Compressor locked out on safety chain trip• Supply fan failure• Heating SAT failure• Cooling SAT failure• SAT,RAT,OAT,IAQ, ST, or RH failure• Duct static or Bldg. Pressure sensor failure• Dirty Filter alarm• High duct static alarm• Hot Water Coil Freeze alarm• External alarm input• Bad Air Proving Switch
SENSOR FAILURES AND DEFAULT OPERATION
A failure of SAT RAT, OAT, IAQ, Space Temperature, or anoutside or return air Relative Humidity sensor will generate acommon error. A failure of the Duct Static or Building Pres-sure sensor will generate another common error. The errorswill be indicated by a Status LED (see Status LED Chart ear-lier in this chapter). The errors will be written to the Error His-tory Buffer. In networked application, the error flag will bereadable by the network. The error indication of a sensor fail-ure will continue until the problem is corrected and will auto-matically terminate when the sensor is again detected asreliable. If the unit is shut down as a result of a sensor failure,the alarm must be reset (after the sensor problem has beencorrected) by resetting the controller (power cycle, or resetcommand issued by the Palm Pilot Configuration Tool).
SAT SENSOR
CV operation: If the SAT sensor fails, the Economizer,excessive SAT control and predicted SAT drop checking willbe disabled. The Control will then continue a "limp along"operation under zone thermostat, or zone sensor control. ForVAV operation the unit will be shut down.
RAT SENSOR
If the RAT sensor fails, Morning Warm Up mode and VAVOccupied Heating are disabled. For Economizer Loadingfunction, the control will default to estimated RAT of 75°F (forthis function only).
OAT SENSOR
Units without Economizer: If there is no Economizer, thecontrol will lockout Cooling on an OAT sensor failure. This isbecause the controller can not determine when cooling needsto be locked out at low OAT to prevent damage to compres-sors. Heating operation will continue normally.
Units with Economizer: All Economizer Operation will bedisabled. This is because OAT sensor is the most essentialsensor in determining availability of free cooling. Even if theunit is equipped with Outside RH sensor and controller couldcalculate Outdoor Enthalpy, the OAT sensor is still essentialin that calculation. The Economizer will only modulate to theMinimum Position when the Fan is operating and the controlis Occupied.
OUTSIDE AIR RELATIVE HUMIDITY SENSOR
If the OAH sensor fails, the control will only use the OAT sen-sor to decide if Free Cooling is available. The control will self-configure to Outside Temperature Method (see also Econo-mizer Operation section earlier in this document).
RETURN AIR RELATIVE HUMIDITY SENSOR
The control will self-configure to Outside Enthalpy Operation.
TABLE 47: STATUS LED CHARTFlash Codes Decription
On Steady Control Failure
1 Flash (Not Applicable)
2 Flashes Control waiting ASCD
OFF No Power or Control Failure
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SPACE TEMPERATURE SENSOR
CV operation with a zone sensor: When this sensor failsthe control will see if it has a RAT sensor. If it has a RAT sen-sor, the control will use it as a backup and continue tempera-ture control to the active space temperature setpoint. If thereis no RAT Sensor, the control will shut down all outputs. If thedetected sensor failure is a short circuit, the error can bedeclared only if the short persists for several minutes, in orderto distinguish a sensor failure from a short caused by some-body pushing on Unoccupied Override button.
VAV operation: If the space temperature sensor fails, thecontrol will continue normal function, only SAT reset fromspace temperature will be disabled.
BUILDING PRESSURE SENSOR
If this sensor fails, the Power Exhaust control will default tooperate as a two position Power Exhaust. The PowerExhaust Fan will be controlled as a fixed speed, ON/OFFPower exhaust fan, controlled from position of the Econo-mizer damper. If the unit is equipped with a ModulatingExhaust Air Damper, this damper will be closed.
DUCT STATIC PRESSURE SENSOR
If this sensor fails, all outputs are turned off and the unit isshut down.
IAQ SENSOR
If the IAQ sensor fails, Demand Ventilation mode is de-acti-vated.
SYSTEM ERRORS
HEATING SAT FAILURE
In Heating mode and all stages of heating energized, the SATmust drive above the Supply Air Alarm Setpoint for Heatingwithin ten minutes or this SAT failure error will be activated.The error will be written to the Error History Buffer. In net-worked application, the error flag will be readable by the net-work.
COOLING SAT FAILURE
In Cooling mode and all stages of compression are ener-gized, the SAT must drive below the Supply Air Alarm Set-point for Cooling within ten minutes or this SAT failure errorwill be activated. The error will be written to the Error HistoryBuffer.. In networked application, the error flag will be read-able by the network.
SUPPLY FAN FAILURE
The conditions under which this failure is declared, and thefollow-up actions of the control when this error occurs aredescribed in a paragraph on Air Proving Switch Operationearlier in this document. The error will be written to the Error
History Buffer. In networked application, the error flag will bereadable by the network.
COMPRESSOR SAFETY CHAIN TRIP
The conditions under which this failure is declared, and thefollow-up actions of the control when this error occurs aredescribed in a paragraph on Compressor Status Monitoringearlier in this document. The error will be written to the ErrorHistory Buffer. In networked application, the error flag will bereadable by the network.
DIRTY FILTER ALARM
The conditions under which this failure is declared, and thefollow-up actions of the control when this error occurs aredescribed in a paragraph on Dirty Filter Switch (DFS) optionearlier in this document. The error will be written to the ErrorHistory Buffer. In networked application, the error flag will bereadable by the network.
HIGH DUCT STATIC ALARM
The conditions under which this failure is declared, and thefollow-up actions of the control when this error occurs aredescribed in a paragraph on Duct Static High Limit Setpointoption earlier in this document. The error will be written to theError History Buffer. In networked application, the error flagwill be readable by the network.
HOT WATER COIL FREEZE ALARM
The conditions under which this failure is declared, and thefollow-up actions of the control when this error occurs aredescribed in a paragraph on FSI (Hot Water Freeze Protec-tion) option earlier in this document. The error will be writtento the Error History Buffer. In networked application, the errorflag will be readable by the network.
THE MILLENNIUM SIMPLICITY CONTROL
INTRODUCTION AND OVERVIEW
Welcome to the new Millennium Simplicity control, a digitalcontrol system designed specifically for the Millennium 25 to40 Ton single package rooftop unit. The Simplicity is composedof 72 monitored and controlled input and output points. Thecontrol logic of the Simplicity extends on the rules built in to theSynthesys control, and provides character displays in additionto LED flashes to display information to the technician.
The Simplicity digital control performs all of the control andmonitoring functions that were originally done by separatediscrete relays, controls, and interlocking hardware. Thisreduces manufacturing, service, and maintenance costs. TheSimplicity digital controller includes sophisticated control ofthe individual components of the HVAC cooling/heating unit,and has built-in rules that protect those components and opti-mize the control to its environment. The cooling and heating
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modes are protected against frequent cycling, slugging, mul-tiple restarts, etc.
One result is that the system may not immediately respondas you expect. For example, internal digital timers may delaythe start of a compressor even though the thermostat calls forcooling. The control may be in the middle of a timingsequence; without the observer knowing what has alreadyhappened and the status of current inputs, the system maytake action not expected by the tech.
In the Simplicity control, there are:• a list of user-selected option settings and setpoints
recorded within the control;
• inputs monitored by the Simplicity;
• specific fixed rules and timings built in to the control
• outputs to compressors, heat, economizers, and other options.
The Simplicity has a real-time clock function, with minimum often hours ‘Time-of-day retention’ with unit power off.
The Millennium Simplicity control is resistor-configured forConstant Volume (CV) units or Variable Air Volume (VAV)units. The option settings for a specific option configurationwill be made as part of unit test at the factory; however, ifthere is doubt about how a unit is responding in the field,check the option setting for the unexplained action.
If connected to a network, the control requests an address bya press of the Address/Down button.
DIAGNOSTICS VIA LED
There is an LED on the board that shows the status of thecontrol and alarms (see Status LED Table). There are twocharacter displays, one 2-digit and one 4-digit, to indicatedetails of run conditions and alarms (see Alarms Table in theTrouble Shooting section of this manual).
When the Alarm / Change Data button (See Figure 2 Simplic-ity Controller Push Buttons) is pushed and released one timewithin five seconds, it will re-enunciate the last five alarms onthe Display.
When this button is pushed and released two times within fiveseconds, it will clear all stored alarms.
The error details for most conditions are stored in summary inthe Simplicity Control and can be accessed by the digital dis-play, personal computer interface, or Palm Pilot (Some inter-faces still in development).
Diagnosing requires patience because of internal timings.Normal observable conditions are the same - contactor 1Mpulled in, compressor 1 running - but the control does notidentify what it has just done or is about to do. The Simplicitycontrol will take action according to its internal rules eventhough action requests come from smart thermostats. A callfor cooling, for example, will be compared with supply airtemperature before energizing a cooling stage.
ERROR HISTORY
The Simplicity control stores up to 5 of the most recentalarms in a First In, First Out (FIFO) manner. As the controlcollects alarms, it will overwrite the oldest alarm after the his-tory buffer becomes full.
Some system errors will initiate a controlling response as wellas being stored in the error memory buffer. See the “Trouble-shooting” chapter in this manual for a detailed description ofhow controller errors are handled.
Data items stored for maintenance / run history, in addition toAlarms:
• Accumulated run times for each compressor and heat stage
FIGURE 31 -SIMPLICITY CONTROLLER
FIGURE 32 -SIMPLICITY CONTROLS PUSH BUTTONS
Program
Alarms / Change Data Address / Down
Test / Reset / Up
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• Unit model number• Unit serial number• Unit Name
DIGITAL LINGO
This training manual is intended to help you with the commis-sioning process by illustrating the use of tools like the con-trol’s digital input and software engineered specifically forstarting up and servicing a Millennium rooftop unit.
You should become familiar with some common terminologyand lingo used in the digital controls industry. [If you are famil-iar with the Synthesys controller, the logic of the Simplicity willbe familiar territory.]
If this is your first exposure to the world of digital controls youmay experience a lot of new terms, acronyms and technicallingo commonly used in the controls industry. For example,the Simplicity input and output hardware points are describedas analog, relating to a continuous scale of value readingssuch as a temperature sensor ranging from -400F to 1600Frange, or binary, meaning 2-states, either on or off, open orclosed, true or false, one or zero. The term “digital” alsomeans two states and its use is often interchanged with“binary”. These points may be either factory- or field-set.
THE PI ALGORITHM
Another common “digital controls” term is the PI algorithm orProportional-Integral control loop. The PI algorithm is a con-tinuously updated math calculation that the controller uses tomodulate an analog output point. For example, a variablespeed drive uses a PI loop to maintain a desired setpoint (inthis case, a duct static pressure value). The algorithm takesinto account several parameters to calculate the output. ThePI loop needs parameters such as the proportional operatingbandwidth, integral time constant, deadband, desired set-point value, sensed input value(s), start up ramp time, initialstart value, maximum output control value, a status point toinitiate the control action (i.e. a fan ON status), Direct orReverse Controlling Action, and several other parameters tocalculate a simple 0 to 100% analog output control. The PIalgorithm is also called a PI loop because it “loops” the outputback to the input (feedback) and determines a new outputvalue based on the “error” or difference between the setpointvalue and the sensed input value, and how that differencerelates proportionally to the 0 to 100% output value. Time isthe ”integral” constant that is factored in to increase ordecrease the controlling output action depending on how longthe sensed value remains away from its desired setpoint.
Fortunately, you do not have to determine all of these param-eters since they are pre-programmed at the factory. You needonly to set a desired setpoint and ensure that the inputs andoutputs are properly wired and working. This is referred to ascommissioning a system.
ANALOG TO DIGITAL CONVERTER
Computers can only understand a simple binary language.Remember, “binary” means two states - ON or OFF. Analog(continuous) values of voltages, currents, and resistances aresupplied by sensors and transducers to the control. Thesevalues must be converted in to a binary code so that the com-puter can understand them. This conversion process is per-formed through a combination of hardware and software. Forexample, the 0-5VDC analog value from a static pressuretransducer is divided into thousands of steps with a binarycoded number, often called “counts”, assigned to each step.
SOFTWARE TERMINOLOGY
A digital controller handles its control functions through soft-ware programming rather than with interlocking hardware andwiring. The software then becomes key to how controlledfunctions are handled. Software is a set of statements(referred to as the “program”) that define the function of thecontroller’s internal microprocessor computer.
Software procedurally tells the computer the sequence andorder of tasks that need to be performed using a languagethat the computer can understand.
Software is stored in a computer’s memory. There are severaltypes of memory in a computer. Each type has a specificfunction to perform.
EPROM - This is “nonvolatile” memory, meaning it will not beerased on a power loss. This memory is usually programmedprior to assembly of the controller. Since this memory is notchanged during normal operation of the Simplicity control,only basic operation instructions are stored in this type ofmemory.
FIGURE 33 -ANALOG TO DIGITAL CONVERTER
BINARY NUMBER EQUIVALENT
0 1 2 3 4 5 6 7------------- n
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EEPROM (Double “E” Prom) - Is also non-volatile, but thistype of memory requires a special process to be written to.This memory can be written to and changed by the micropro-cessor. This is the type of memory that the control program isstored in the Simplicity control.
ROM - Read Only Memory is non-volatile but can not be writ-ten to. This memory is programmed only once before the con-troller is assembled. ROM contains instructions specifically forthe internal microprocessor computer in the controller.
FIRMWARE - “Firmware” is software, program instructions orapplications, but stored in EPROM or ROM memory.
RAM - Random Access Memory is a volatile memory. It will beerased when a power fail occurs. This memory is used as akind of “scratch pad” for the controller. Temporary instructionsand information such as an output controlling action like drivingthe economizer dampers open is stored here. When a powerloss occurs or if the controller is sent a manual reset using acontrol push button, this memory is cleared and initialized.
Other filtered inputs include temperature and humidity sen-sors. You should be aware of this filtering effect because itwill appear the controller is not acting as fast as you maythink it should. In reality, it is acting and controlling on thesetime-averaged and weighted values.
FAULT TOLERANCE - Fault Tolerance of the Simplicity con-trol involves two issues: Hardware fault tolerance deals spe-cifically with the electrical characteristics of the controller -how much over voltage or power surge the controller canwithstand before damage occurs, and whether internal com-parisons are verifying that the control is calculating and com-municating properly. Software fault tolerance in thistechnology consists of comparing results to previous valuesand to reasonable values.
COMMUNICATIONS BUS
Networked communications may also be new to you. Itrelates to connecting several Millennium rooftop units to anetwork that can be monitored and controlled remotely fromnetwork computer workstations. You will find this typically onlarge installations where central control, monitoring, andenergy management issues become a critical factor in oper-ating a large complex such as a manufacturing facility.
The Simplicity Control has the ability to be networked into alarger system using the MODBUS communication protocol. Acommunication protocol is simply a set of rules that deter-mine how two systems communicate with each other oversome medium such as a pair of wires, phone line, radiowaves, etc. The transmission medium may also be called agateway, pathway, or bus. An “open” protocol such as MOD-BUS is a publicly published set of rules that any equipmentmanufacturer can use to network into another manufacturersequipment.
OPTIONAL ModLINC TRANSLATOR
Overview
The ModLINC translator operates as a Modbus® Client pro-viding an interface between a BACnet® control system anddevices that communicate using the Modbus® RTU protocol.The ModLINC is preconfigured to provide an interface toYORK UPG products equipped with an Intelli-Comfort or Sim-plicity-Elite controller and allows monitoring and control by anISN ConneXsys or third-party BACnet® Building AutomationSystem (BAS).
The ModLINC communicates using the Modbus® RTU proto-col on one port and BACnet® MS/TP, which is the protocolused by ISN ConneXsys devices, on the other port. By pro-viding different communication protocols on the two ports,data can be retrieved from and provided to two different sys-tems.
The ModLINC mounts inside the control panel of the UPGunit and utilizes 24 VAC power from the unit's control trans-former. One port is connected to the UPG controller. Theother port must be connected to the ISN ConneXsys/BAC-net® network.
The ModLINC translator is preconfigured to obtain opera-tional data points from the controller and expose them on anISN ConneXsys/BACnet® network. The data can be trans-ferred to any network device, including an ISN ConneXsysOWS.
"The ModLINC device is primary a control offered and config-ured by York's ESG (Engineering Systems Group). Thedevice is designed to tie into and function with the ISN Con-neXsys system. The device can be used with other BACnet®MS/TP systems, but a qualified controls contractor must beinvolved. UPG cannot support the ModLINC device beyondits hardware functionality and cannot guarantee functionalitywith the ISN or other third party BAS device."
Please refer to the ModLINC Installation/Application manualPart Number 126367-UIM-A-0305.
COMPONENT DESCRIPTION
This section describes the main components of MillenniumSimplicity control. These components consist primarily ofcontrollers, hardware to handle signal input and control out-put and the Tstat interface terminals.
THE SIMPLICITY CONTROLLER
Simplicity is a proprietary, microprocessor-based controller foruse in HVAC applications. The controller provides monitoringand control for either VAV or CAV for a total of 22 outputs.
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WIRING AND TERMINATION, COMMUNICATIONS
Most connections to the Simplicity Control are by wiring har-nesses. There are also screw terminal connections for ther-mostat inputs and for communications via an RS-485 port.
COMMUNICATION ADDRESS:
The communication address button (lower right of the dis-play) is used to identify a Millennium rooftop unit to a network,and “capture” the next available network address for that unit.Millenniums can be networked together for centralized moni-toring and control. Much like we need a unique street addressin our homes so we can receive our postal mail or emergencyservices, these units also need a unique address so the cen-tral Facilities Management System (FMS) can “talk” to eachunit individually. The Simplicity board has the model andserial number of the specific unit and has a memory space fora customer name to be applied. So the entire identification fora specific unit available to the network could be, for example,Y2AC04M3KDGABA, NCNM123456, SOUTH OFFICE.
The one-time commands to Override ASCD timers and/or tostart Run Test can be issued by the Test/Reset/Up pushbut-ton. When this button is pushed and released within five sec-onds, the control will zero all ASCD’s for one cycle.
ACRONYMS
A number of acronyms are used throughout this training man-ual. These are specific to the Simplicity control. They are alsoused in the Technical Guide and Installation and Operationmanuals. Acronyms are used to refer to input and outputhardware points and software parameters such as timingdelays and setpoints.
The acronyms used throughout this training manual are listedin the Acronym Table 48. They are described in much moredetail below.
INPUTS
There are two types of hardwired input points on the Simplic-ity control: Analog and Binary. These may be sensors, feed-back, or adjustable setpoints. Typical analog inputs [AI]
TABLE 48: ACRONYMSINPUTS DESCRIPTION
APS Air Proving SwitchIAQ Air Quality (CO2 Sensor)
BAS Economizer Passes BAS economizer command through to Economizer output
BPS Building Pressure SensorC1O-C4O Compressor Status
DF Dirty Filter StatusDPS Duct Pressure SensorFSI Hot Water Coil Freeze InputG Thermostat input for Fan
GV1-3 Monitors gas valve actuation call
HPS1-4 High pressure switch monitored forcompressor discharge
LPS1-4 Low pressure switch monitored for compres-sor suction
Lim 1-3 Over-temperature limit switch from heat stages
OAT Outside Air TemperatureOCC Building Occupied StatusPurge Building Purge input
RAT Return Air TemperatureSAT Supply Air TemperatureSD System Shutdown Connector
OAH Outside Air EnthalpyRAH Return Air EnthalpySSA Setpoint AdjustST Space Temperature
W1, 2, 3 Heating Stages from TstatY1,2 3, 4 Cooling Stages from Tstat
PUSHBUTTONS DESCRIPTIONTest/Reset / 'Up 'Test / control reset / Data value incrementAddress / 'Down 'Change data / Data value decrement
Alarms / Advance data Show alarms / go to next data pointProgram Go to program mode
Real Time Clock Incorporated on the boardOUTPUTS DESCRIPTION
Status LED Flash to indicate alarm, otherwise'heartbeat'
Digital displays One 2-character and one 4-characterC1-C4 Cooling Outputs 1 through 4CF1, 2 Cond Fan Bank 1, 2ECO Economizer damper outputEXH Exhaust Fan relay output
EXD Exhaust Air Damper / Exhaust VFD Signal Output
Fan Supply Fan relay output [contactor orpermission relay]
H1, 2, 3 Heating Stages 1, 2, and 3 outputHGR Hot gas reheat [future]HWV Hot Water Valve output VFD Supply Fan IGV or VFD Signal Output
X Alarm signalMiscellaneous Description
AI Analog InputAO Analog OutputBI Binary Input same asBO Binary OutputCAV Constant Air VolumeVAV Variable Air VolumeVFD Variable Frequency DriveIGV Inlet Guide VaneIAQ Indoor Air QualityPI Proportional-Integral Control
ASCD Anti Short Cycle Timer (Compressor)
TABLE 48: ACRONYMS (Continued)
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include Space Temperature (ST), Supply and Return Air Tem-peratures (SAT, RAT), and Building Pressure Sensor (BPS).The binary inputs (BI) on the Millennium Simplicity use a drycontact input to determine the status of a monitored point.Typical BI points are Fan Status (APS), Filter Status (DFS),and Compressor Status (HPS1-4, LPS1-4, C1O-4O).
ANALOG INPUTS (AI):
Analog inputs require parameters that define the input’s char-acteristics. Attributes of an AI include the linear range, alarmlimits, alarm differential, change of state (COS) enable, andfilter weight. The input values may be overridden by a exter-nal system command or by using the input buttons on theSimplicity board. This is useful to override current conditionsto test certain control functions or modes.
BAS - Economizer override; if this option is enabled, anexternal BAS system will control the economizer 2-10 VDCsignal through this pair of terminals.
ST - Space Temperature sensor is a field installed sensor(PN: 025-38928-000 - w/ Override Button). The sequence ofcontrol for space temperature is different depending onwhether the system is a VAV or CAV. See chapter onSequence of Operation for a detailed description of the STcontrol modes.
SSA - Space Temperature Adjust is field installed. It is a slideadjustment located on a space sensor (PN: 025-38927-000)with a slide bar potentiometer. It is used to offset the spacetemperature setpoint. This slide-bar is a 10K ohm potentiom-eter. The programmable range for the Setpoint adjust is +/-5°F. For example, if the Space Temperature setpoint is set to74°F, the SSA is programmed to +/- 3°F and the SSA isadjusted fully to the + position, the new controlling space set-point will be 78°F.
OAT - The outside air temperature sensor (PN: 031-01916-000A) is a factory-installed 10 K NTC sensor. Its linear rang-ing is from -50°F to 250°F.
OAH - Outside Air Humidity (PN: 031-09127-000-A) is a fac-tory-installed sensor manufactured by MAMAO. The OAHsensor, installed only with enthalpy economizer, provides a 0-10 VDC signal to the controller over a range of 0 to 100% rel-ative humidity. This input is used for the economizer calcula-tion to determine whether free cooling is available and toswitch between minimum outside air and using outside air asthe first stage of cooling.
SAT - Supply Air Temperature sensor (PN: 031-01915-000A)is a factory-installed -50°F to 250°F, 10 K NTC sensor.
RAT - Return Air Temperature sensor (PN: 031-01917-000A)is a factory-installed -50°F to 250°F, 10 K NTC sensor.
RAH - Return Air Humidity (PN: 031-09127-000-A) is a fac-tory-installed sensor manufactured by MAMAO, installed only
with dual enthalpy economizer. The control will calculate thereturn air enthalpy using the relative humidity and return tem-perature inputs.
LOW VOLTAGE DETECTION - This input monitors the 24VAC for low voltage conditions. The input has two thresholds,one at 16 VAC and one at 19.2 VAC. If the control needs toturn on a contactor, it will look to see if the voltage isabove19.2 VAC before it will turn it on. If the voltage is notabove 19.2 VAC, it will hold off the contactor and flash theappropriate flash code. This flash code is not an alarm. If thecontrol already has contactors pulled in, it will monitor thevoltage and drop the contactors and shut down if the voltagedrops below 16 VAC and flash the appropriate flash code.
REMOTE - the control will use 0-10 VDC from third-partyBAS to control SAT setpoints. Thermostat inputs override if inconflict with Remote Control voltage input.
SPC TEMP - offset value from the space sensor offset poten-tiometer.
CV/VAV - resistive value across terminals, to determinewhich supply fan rules the control will follow.
Demand Ventilation / IAQ - Indoor Air Quality. The IAQexpects a 0-10 VDC signal to the control from a field suppliedand installed Carbon Dioxide (CO2) sensor. Indoor air qualityis monitored for adequate ventilation. In Demand VentilationMode, as the CO2 levels in the building rise above the pro-grammed setpoint, more fresh air must be brought in. Theeconomizer is therefore adjusted to a more open position asnecessary. The linear ranging for IAQ sensor input is from 0to 10,000 ppm. The Demand Ventilation setpoint is adjustablefrom 0 to 2000 ppm and is set at the factory at 1000 ppm.
DPS - Duct Pressure Sensor is monitored by a factory-installed 0-5 VDC transducer (PN: 031-01209-000A). Thehigh-pressure port sensing tube is installed in the field. Thesense tube should be located approximately two thirds of theway down the duct plenum. To prevent an unstable signaldue to air turbulence, there should be no obstructions, turnsor VAV terminal boxes up or down-stream of the sense tubelocation for at least 6 to 10 times the diameter of the duct.The sensor is located in the control box just below the Millen-nium Simplicity control.
BPS - The Building Pressure Sensor (PN: 031-01262-000A)is a factory-installed Johnson Controls DPT-2640-522 trans-ducer that provides a 0 to 5 VDC signal to the controller overa range from -0.25”WC to +0.25”WC. The transducer islocated in the control box just below the Millennium Simplicitycontrol. The sense tubes are field installed with the outsidepressure being sensed external to the unit. To avoid anerratic pressure reading, the building pressure sense tubeshould be mounted in an area away from the return air grill,discharge diffusers, doors and windows.
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BINARY INPUTS (BI):
APS - Supply Fan status is monitored by an Air Proving Sta-tus switch (PN: 024-27557-000A) installed at the factory. TheAPS monitors the difference in pressure between the suctionand discharge of the fan.
C1O through C4O - These four binary inputs report the statusof the Compressors 1 through 4 overload modules.
FOVR - Monitoring loop through the supply fan overloadmodule.
HPS1-4, LPS1-4 - The refrigerant high pressure (HP) and lowpressure (LP) safety switches, are independently monitoredby the Millennium Simplicity. If any switch opens, the controlvoltage from the control binary output is interrupted and thestatus is monitored by the control.
G, OCC, P - These signals represent Fan (G), Building Occu-pancy (OCC), and Building Purge (P) calls from the thermo-stat. If a thermostat is installed on the system, these inputsare connected to the thermostat interface board just as arethe cooling/heating calls. These inputs are connected throughthe Tstat Interface board directly to the respective binaryinputs of the Controller. These signals are, however, eachloaded with a resistor to maintain voltage levels and to pre-vent “floating” of signals. Thermostat wiring is typically notshielded and may have induced voltages that could causeerrant signal readings by the controller.
FILT - Dirty Filter switch [customer supplied, field installed onfactory-provided harness connections] input to provide a filterstatus to the control. The control will alarm only after 24V hasbeen sensed for ten minutes.
GV1-3 - Monitoring that voltage is being supplied to gasvalves on optional heat stages.
LIM1-3 - Overtemperature inputs from optional heat stages.
FSI - Freeze Stat is a customer installed temperature switchon the FSI input to the controller to tell the control that a tem-perature has occurred that risks the hot water or steam coil.
Y1-4, W1-3 - If a thermostat is installed on the system, theseinputs will take priority over software programmed setpointsand limits.
SD - This terminal set allows attachment of an external shut-down NC contact. 24VAC power is supplied to the board atSD2; a factory installed jumper passes that power to terminalR to power the Simplicity Elite board. If an external shutdownsignal is required at a particular installation, remove thejumper and connect the NC shutdown circuit between SD1and R.
OUTPUTS
Analog Outputs (AO) - Analog outputs provide a 2-10 VDCsignal to operate controlled devices. The Simplicity is cur-rently configured to use only 2-10 VDC outputs to the Vari-able Frequency Drive, Inlet Guide Vane, EconomizerDamper, Power Exhaust Dampers or VFD, and Heating watervalves. Since these outputs are analog, they are continuousbetween 2 and 10 Volts and are proportional to the 0 to 100%drive position of the device.
ECO - Economizer Actuator - The modulating Economizeruses a Belimo AF24-SR.9 spring-return actuator (PN: 025-30869-000A). This actuator uses a 2-10 VDC signal to drivethe dampers open. The actuator drives 95 degree rotation.Note the chart below for a correlation between the input drivesignal at terminal 3 (Y1) of the Belimo actuator and the corre-sponding output drive position of the damper:
VFD - Inlet Guide Vane or VFD. The Inlet Guide Vane usesa Belimo GM24-SR spring-return actuator. This actuator usesthe 2-10 VDC signal from VFD+/- terminals to drive thedampers open. The actuator drives 95 degree rotation. Notethe chart below for a correlation between the input drive sig-nal at terminal 3 (Y1) and the corresponding output driveposition of the guide vane. If the unit has a factory-installedVariable Frequency Drive, the 2 to 10 VDC signal is wiredfrom VFD+/- output directly to the VFD’s signal input termi-nals to control fan motor speed.
TABLE 49:INPUT SIGNAL TO Y1 ACTUATOR POSITION
Input Signal to Y1 Actuator Position10 VDC 90 degrees
9 788 677 566 455 334 223 112 00 -5
8VDC over a 90 degree Span = 11.25 degrees/VDC
FIGURE 34 - VFD CONTROL WIRING
VFDFR
FRFan
VFD +
VFD -
Simplicity12
18
53
55
P13-1
P14-1
P14-2
Wht
Blk
TB2
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EXD - Power Exhaust Damper Vane or VFD - PowerExhaust Damper Actuator is a BELIMO AF24-3-S 24VAC. Ituses a full open/ Full Closed scheme and operates a 95degree rotation. If VFD Power Exhaust is configured, thesame signal controls the exhaust fan motor drive frequency.
HWV - Heating Water Valve - Customer supplied andinstalled, connect to factory-provided harness.
BINARY OUTPUTS (BO)
FAN - Fan Start/Stop Relay, VFD “permission” relay FR
H1-3 - HEAT STAGES 1 TO 3 [OPTIONAL]
C1 through C4 - Cooling Stages 1 through 4
CF1 & CF2 - Condenser Fan Banks 1 and 2
X - Controller Alarm is field-wired from the thermostat inter-face board to signify a controller alarm has occurred.
TABLE 50: SIMPLICITY CONTROL INPUTSName Range Resolution Precision Description
Y1 18 - 30 VAC On - Off +/- .5 VAC Request for the first stage of Cooling (24 VAC sense) Tstat Screw Terminal
Y2 18 - 30 VAC On - Off +/- .5 VAC Request for the second stage of Cooling (24 VAC sense) Tstat Screw Terminal
Y3 18 - 30 VAC On - Off +/- .5 VAC Request for the third stage of Cooling (24 VAC sense) Tstat Screw Terminal
Y4 18 - 30 VAC On - Off +/- .5 VAC Request for the fourth stage of Cooling (24 VAC sense) Tstat Screw Terminal
W1 18 - 30 VAC On - Off +/- .5 VAC Request for the first Stage of Heating (24 VAC sense) Tstat Screw Terminal
W2 18 - 30 VAC On - Off +/- .5 VAC Request for the second Stage of Heating (24 VAC sense) Tstat Screw Terminal
W3 18 - 30 VAC On - Off +/- .5 VAC Request for the third Stage of Heating (24 VAC sense) Tstat Screw Terminal
G 18 - 30 VAC On - Off +/- .5 VAC Request for the Fan (24 VAC sense) Tstat Screw Terminal
R 18 - 30 VAC - - These terminals are a ¼' Female Faston and a Thermostat Screw terminal connected to the power supply of the board.
C Earth Ground - - These terminals are a ¼' Faston and a Thermostat Screw termi-nal.
OCC 18 - 30 VAC On - Off +/- .5 VAC Occupied input (24 VAC sense) Tstat Screw Terminal
C1 Class 1 Relay Contacts - - Compressor number one contactor output (Relay Contacts - 24
VAC/120 VAC)
C2 Class 1 Relay Contacts - - Compressor number two contactor output (Relay Contacts - 24
VAC/120 VAC)
C3 Class 1 Relay Contacts - - Compressor number three contactor output (Relay Contacts - 24
VAC/120 VAC)
C4 Class 1 Relay Contacts - - Compressor number four contactor output (Relay Contacts - 24
VAC/120 VAC)
CF1 Class 1 Relay Contacts - - Condenser Fan contactor output (Relay Contacts - 24 VAC/120
VAC)
CF2 Class 1 Relay Contacts - - Condenser Fan contactor output (Relay Contacts - 24 VAC/120
VAC)
Fan Class 1 Relay Contacts - - Fan contactor output (Relay Contacts - 24 VAC/120 VAC)
Exhaust Fan (EXH) Class 1 Relay Contacts - - Exhaust Fan contactor output (Relay Contacts - 24 VAC/120
VAC)
Supply Fan VFD 2 - 10 VDC - - This is a 2 - 10 volt output capable of 10 ma
Exhaust Fan Damper (EXD) 2 - 10 VDC .1 VDC .1 VDC This is a 2 - 10 volt output capable of 10 ma
Hot Water Valve (HWV) 2 - 10 VDC .1 VDC .1 VDC This is a 2 - 10 volt output capable of 10 ma
Hot Gas Reheat 2 - 10 VDC .1 VDC .1 VDC This is a 2 - 10 volt output capable of 10 ma
Economizer (ECO) 2 - 10 VDC .1 VDC .1 VDC This is a 2 - 10 volt output capable of 10 ma
X 24VDC - - This is a 24VDC output for Alarms
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SIMPLICITY PROGRAMMING OPTIONSThe paragraphs below provide a definition of, and specify thefunction related to, each of the parameters that are field-adjustable using the interfaces available. The Millennium Unitis shipped from the factory with the necessary options pre-programmed as indicated by the model nomenclature. It isalways a good practice, though, to verify that the correctparameters are properly configured for the unit you are com-missioning. You can find a complete list of field-adjustableparameters in the “Settable System Parameters”.
For a description of the parameters, see the Settable Sys-tem Parameters below and Table 52.
INTERACTING THROUGH THE MILLENNIUM SIM-PLICITY
SET THE CLOCK
• Power up the unit.• Press the Program button [upper left].• Press the Test/Up button [upper right]. Hold it in and it
will step through the parameters, or push in to advance one parameter at a time. Advance to parameter 63, Hours.
• Press Change [lower left] Press Up [upper right] or Down [lower right] to the correct hour [24 hour time].
• Press Change to enter the new value.• Press Up to get to parameter 64, Minutes.• Press Change.• Press Up or Down to get to the correct minute value.
Press Change to enter the new value.• If you are done changing parameters, press Program to
exit the program mode.
PARAMETER SETTING
The buttons allow the operator to go to a specific parameterand to view and change the data in that parameter.
• To enter the parameter setting mode, press the Pro-gram button. The control will display the current parameter number in the two-digit display, and the present value of that parameter in the four-digit dis-play.
• To change to another parameter, press the /Up or /Down button to move to the address of the desired parameter. The present value of that parameter will display.
• To change the data, press the /Change button. The value will flash. While it is flashing, press the /Up or /Down button to increase or decrease the value.
• When the desired new value is showing, press the /Change Data button again to tell the control to store the new value. You can verify that the new value is in place when the value stops flashing.
• To exit Program mode, press the Program button again.
INITIAL STARTUP OPTIONS
Commissioning a new Millennium installation requires somefield adjustments to the Simplicity control program. Most ofthese adjustments simply involve setting up the various set-points that are specific to your customer’s needs (i.e. buildingpressure) or enabling some extended options that are inte-grated into the Simplicity control. Also, if there are fieldchanges, i.e. a modulating power exhaust option, the controlconfiguration will need to be modified for the new option.
METRIC OPERATION (ENGLISH)
The factory default for this option is OFF. The metric (SI) con-versions are part of the controller software; when the Metricparameter is selected, temperature setpoints and readingswill convert to Centigrade (°C).
SETTABLE SYSTEM PARAMETERS The following headings list each parameter’s name and itsdefault setting. The control is set at the factory for the optionsof the specific unit; if a replacement control is being installed,the entire parameter set must be matched to the unit. Thenumber in (parentheses) is the value of a parameter in an un-configured control.
Compressors - (2) - This tells the control the number of com-pressors available. The Factory Default [the value in anunconfigured replacement control] is 2 and can be adjustedfrom 1 to 4.
Heat Stages - (2) - This tells the control the number of heat-ing stages available. This parameter may be set from 0 to 3.The default setting is 2 stages of heat.
Hydronic Heat - (OFF) - This tells the control that a HotWater Coil is installed. If the control is going to modulate theHot Water Valve it will also turn on the Heat One output. Thisis to energize the VAV heat relay for the VAV boxes. Thedefault is OFF for this option. If this parameter is enabled,remember to set the Hydronic Heat First and Second StageSetpoints and the Economizer Loading Setpoint found in the”Simplicity Setpoints”.
Stage 1 Hydronic Heat SAT Setpoint - (120°F) - When theHydronic Heat option is enabled, the control will maintain thisSAT setpoint for a call for first stage Heating, by modulatingthe Hot Water Valve. This is the reset temperature whenoperating a VAV unit in the Heating mode. The reset rangefor SAT setpoint is from 80°F to 180°F with 120°F shipped asthe default.
Hydronic Heat Reverse Actuated Valve - (OFF) - This set-ting is to allow convenient use of reverse acting water valves;setting this parameter to (ON) will change the signal to 2VDC= open, 10 VDC = closed.
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SAT Control for Cooling - (ON) - This tells the control if it isgoing to do excessive SAT monitoring and tripping or not, forCooling. The SAT should be maintained in an acceptablerange in order to achieve reliable compressor operation. Thecompressor trip limits are user adjustable between 40°F and65°F in one degree increments. The default cooling trip limitsare 50°F for stages 2-4, and 45°F for stage 1. When the SATdrops below the trip limit for each respective compressor, thatcompressor is locked out and a 5 minute ASCD is initiated forthat compressor. If this option is enabled, remember to setthe compressor cooling limits for low limit trip.
Power Exhaust - (ON) - This tells the control if it has thePower Exhaust option installed.
Economizer Damper Position for Exhaust Fan to turn ON(Non-Modulating PE Only) - (60%) - This tells the controlthe Economizer Damper position to turn on the Exhaust Fan.This value is based on the 0%-100% output drive signal fromthe controller to the economizer damper actuator.
Economizer Damper Position for Exhaust Fan to turnOFF (Non-Modulating PE only) - (20%) - This tells the con-trol the Economizer Damper position to turn off the ExhaustFan. This value is based on the 0%-100% output drive signalfrom the controller to the economizer damper actuator.
Modulating Exhaust - (OFF) - This tells the control if thePower Exhaust is Modulating or not. A modulating exhaustwill be equipped with a Building Pressure Sensor [BPS]. ANon-Modulating exhaust will look to the economizer damperposition to energize the EXD output. If the sensor gets dis-connected, or fails, an alarm is set. The alarm can be turnedoff by correcting the sensor problem (or; by turning off thisoption). The control is not in this case self-configuring. It willnot automatically use the Building Pressure Sensor if thesensor is connected.
Exhaust VFD Installed - (OFF) - If the unit has a VFD, theEXD output will be enabled when the supply fan is ON.
Exhaust Damper Position For The Exhaust Fan To TurnOn (Modulating Only) - (80%) - This tells the control theExhaust Damper position at which to turn on the ExhaustFan. This value is based on the 0%-100% output drive signalfrom the controller to the damper actuator.
Exhaust Damper Position For Exhaust Fan To Turn Off(Modulating Only) - (20%) - This tells the control theExhaust Damper position to turn off the Exhaust Fan. Thisvalue is based on the 0%-100% output drive signal from thecontroller to the damper actuator.
Building Pressure Setpoint - (+0.100”WG) - This is thepressure setpoint the control will maintain when operating aPower Exhaust. The Building Pressure Setpoint is adjustablefrom -0.200”WG to +0.200”WG. The factory programmeddefault is +0.100”WC. This setpoint is used when the exhaustcontrol is implemented as Proportional Control (with a Modu-
lating Exhaust Air Damper or VFD controlled from buildingstatic pressure), or as a Two-position Control using buildingstatic (Power Exhaust Fan controlled on-off from buildingstatic pressure).
Economizer - (ON) - This tells the control that there is anEconomizer Installed.
Economizer Min Position - (20%) - This tells the controlwhat the minimum outdoor damper position will be for theOccupied mode. Adjustable from 0-100%, the EconomizerMinimum Position default is 20%.
Economizer First Stage Setpoint - (55°F) - This tells thecontrol what Supply Air Temperature to maintain for a call forfirst stage of cooling. This is used only during Constant Vol-ume cooling mode with Economizer operation. The setpointis set at 55°F with an adjustable range from 40°F to 65°F.
Economizer Second Stage Setpoint - (50°F) - This tells thecontrol what Supply Air Temperature to maintain for a call forsecond stage of cooling. This is used only during ConstantVolume cooling mode with Economizer operation. This set-point is set at 50°F with a range from 40°F to 65°F.
Outside Air Humidity (OAH) Sensor Enable - (OFF) - Thissetting tells the control that it is expected to use Outside AirEnthalpy (calculated from Outside Air Temperature and Out-side Air Relative Humidity sensed values) to decide if OutsideAir can be used for cooling.
The control is self-configuring to the best available decisionstrategy for free cooling availability. For example, if it detectsthat OAT and OAH and RAT and RAH sensors are all con-nected and reliable, will self-configure for Differential Enthalpyoperation. If one of the return air sensors should fail, the con-trol will reconfigure for Outside Enthalpy operation, etc.
If the OAH Sensor Enable option is turned ON, it means thatthe Outside Enthalpy Operation, or better decision strategy, isexpected (and supported by installed sensors). If the appro-priate sensors are not installed, or one of them failed, a sen-sor failure alarm is set. The alarm can be turned off by turningoff the OAH Sensor Enable option. Thus, the option setting isused to reflect the desired operation and mainly to controlsensor failure alarms.
The option setting can be viewed as specifying that (the self-configured economizer decision strategy has to be at leastthis, or better, otherwise an alarm is set). If the option is OFF,the control still may self configure to Outside Enthalpy Opera-tion, or even to Differential Enthalpy Operation (if all neededsensors are available), but this option setting will allow alsothe decision strategy based on only OAT (in case other sen-sors fail, or are not installed) without setting an alarm.
Outside Air Enthalpy Setpoint - (27 BTU/LB) - This tells thecontrol an outside air enthalpy limit. Below this limit, outsideair is available for cooling. See enthalpy chart. This parame-
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ter uses a one BTU/LB hysteresis on each side of the limit.The limit is preset to 27 BTU/ LB with an adjustable rangefrom 10 to 50 BTU/LB.
Return Air Humidity (RAH) Sensor enable - (OFF) - Thistells the control that it will compare Outside Air Enthalpy (cal-culated from Outside Air Temperature and Outside Air Rela-tive Humidity sensed values) and Return Air Enthalpy(calculated from Return Air Temperature and Return Air Rela-tive Humidity sensed values). The control will use the airstream with the lower enthalpy for cooling.
The control is self-configuring to the best available decisionstrategy for free cooling availability. For example, if it detectsthat OAT and OAH and RAT and RAH sensors are all con-nected and reliable, will self-configure for DifferentialEnthalpy operation. If one of the return air sensors should fail,the control will stop using rules that involve RAH and set analarm.
If the RAH Sensor Enable option is turned ON (and sup-ported by installed sensors), Differential Enthalpy Operationcan be enabled. If the appropriate sensors are not installed,or one of them failed, a sensor failure alarm is set. The RAHalarm can be turned off by turning off the RAH Sensor Enableoption. Thus, the option setting is used to reflect the desiredoperation and mainly to control sensor failure alarms.
Economizer Loading to Control SAT - (ON) - This tells thecontrol if it is going to use Economizer Loading to controlexcessive SAT [supplying warmer outside air to keep SATfrom going too low]. This parameter is only applicable outsidethe normal Economizer operation. During the Economizeroperation, the loading function is always performed and is anintegral part of the control algorithm.
Duct Static Setpoint - (1.5”WG) - This parameter is applica-ble only to VAV mode of operation. This is the pressure set-point that the control will maintain when operating the fan in aVAV unit. This setpoint is adjustable between 0”WG and5”WG with the default set to 1.5”WG.
Duct Static High Limit Setpoint - (4.5”WG) - This parame-ter is applicable only to VAV mode of operation. This tells thecontrol at what Static Pressure to shut down the unit due to aFan control failure. This setpoint is to insure that we don'tcontinue to operate the Fan with an Inlet Guide Vane or VFDproblem that could cause the ductwork to fail from duct pres-sure. When the Static Pressure reaches this setpoint(4.5”WG default), the control will drive the supply fan controloutput to zero. If the static pressure does decrease below the“Duct Static High Limit Setpoint” within 3 seconds afterdecreasing the supply fan control output to zero, the controlwill resume normal operation. If there is no change in staticpressure after 3 seconds, the control will generate a HighDuct Static alarm, shut down all the outputs including the Fanand shut down the unit. The alarm is written to the Error His-tory Buffer and will trigger storing a snapshot of Points
Screen data along with a date and time stamp. In networkedapplications, the alarm flag is readable by the network. Thisparameter can be adjusted from 0”WG to 5”WG with the fac-tory default set to 4.5”WG.
The customer must be aware of the duct pressure designlimit, and what the duct pressure sensor will be reading whenthe peak pressure is reached [the pressure pickup tube maynot have been located at the place of highest pressure in thesystem].
The alarm must be reset (after the problem that caused thealarm is corrected) by resetting the controller by turningpower to the unit off and back on, or by reset commandissued by an external connection.
Morning Warm Up - Is inferred from the entries in Occu-pied/Unoccupied
Occupied - (from settings in Weekly Schedule and Holi-day Schedule Tables 44 and 45.) - See discussion inSequence of Operation.
Unoccupied - (from settings in Weekly Schedule and Hol-iday Schedule Tables 44 and 45.) - See discussion inSequence of Operation.
VAV High Temperature SAT Setpoint for Cooling - (60°F) -The control will maintain this SAT when operating in VAVmode with a thermostat that is calling for first stage cooling.This parameter may be adjusted from 40°F to 70°F with 60°Fset as the default value.
VAV Low Temperature SAT Setpoint for Cooling - (55°F) -The control will maintain this SAT when operating in VAVmode with a thermostat that is calling for second stagecooling. This parameter may also be adjusted from 40°F to70°F with 55°F set as the default value.
VAV SAT Reset Setpoint - (72°F) - This parameter is usedonly in VAV mode with a Space Sensor. The control willswitch from the VAV Lower Cooling SAT Setpoint to the VAVUpper Cooling SAT Setpoint when this Space TemperatureSetpoint minus 0.5°F is reached. The control will switch fromHigh setpoint back to Low setpoint when the space tempera-ture gets 2°F above this setpoint. This is SAT reset based onSpace Temperature. The reset occurs in both Occupied andUnoccupied modes and may be adjusted from 40°F to 85°F.The factory default is 72°F.
VAV Occupied Heating - (OFF) - This option applies in VAVmode with a Space Sensor and does not affect VAV Occu-pied heating if requested by a thermostat. When this option istoggled on, a VAV unit is able to operate heating in the occu-pied mode as long as it is operating with a Space Sensor. Ifthe Space Temperature drops to 2°F below the VAV SATReset Setpoint the control will read the RAT. If the RAT isbelow the Morning Warm Up RAT Setpoint the unit will enter
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the Occupied Heating mode. Operation is the same as Morn-ing Warm Up. This parameter is factory set to OFF.
Comfort Ventilation Mode - (OFF) - Comfort Ventilation is aSAT control mode that controls SAT during “satisfied” periodsin a fairly wide temperature band, using mostly Outside Air,and also cooling and heating stages as necessary. It is avail-able only on the Constant Volume unit.
To enable Comfort Ventilation, the programmable parameter“Comfort Ventilation Mode” must be set to ON (default settingis OFF).
For a detailed explanation of Comfort Ventilation, refer to theSequence of Operation in this manual.
Comfort Ventilation High Supply Air Setpoint - (80°F) -This is the High Limit Setpoint for the Comfort Ventilationmode. For a stable operation of Comfort Ventilation function,the High Supply Air Setpoint should be set 10.0°F or moreabove the Low Setpoint.
Comfort Ventilation Low Supply Air Setpoint - (70°F) -This is the Low Limit Setpoint for the Comfort Ventilationmode. For a stable operation of Comfort Ventilation function,the Low Supply Air Setpoint should be set 10.0°F or morebelow the High Setpoint.
Dirty Filter Switch - (OFF) - This tells the control that a DirtyFilter Switch is connected to it. The control will wait for tenminutes after the switch has closed before declaring a DirtyFilter Alarm. The alarm is written to the Error History Buffer. Innetworked applications, the error flag is readable by the net-work. The alarm will automatically reset when the error condi-tion is corrected.
The default is OFF.
Heating Lockout on OAT - (75°F) - This is the Outside AirTemperature Setpoint that the control will use to lock outHeating when the OAT is above this setpoint. There is a one-degree hysteresis on each side of the setpoint. This parame-ter is adjustable between 0°F and 100°F with the default setto 75°F.
Heating Lockout on OAT affects only staged heating, it doesnot affect hydronic heat. If the heating is energized when OATreaches this setpoint, the Status LED will indicate the lockoutcondition immediately, but the control will finish the heatingmode and then lock out the heating.
Note that a Heating Lockout on OAT may occur while the con-trol is in a heating mode and there is a demand for heating.
If the OAT then decreases below the lockout setting while thecall for several heat stages exists, the heat stages will turn onsimultaneously. This is considered acceptable as this situa-tion is not expected to occur frequently.
Cooling Lockout on OAT - (45°F) - This is the Outside AirTemperature Setpoint that the control uses to lock out Cool-ing when the OAT is below this setpoint. Adjustable from 0°Fto 100°F, the default is 45°F.
Unoccupied Heating Setpoint - (60°F) - This value is theUnoccupied Heating Setpoint. It is used in both CV and VAVmode of operation (in VAV, it controls Unoccupied heatingwith a Space Sensor).
The control will attempt to correct wrong temperature overlapsettings; for example, if a change is made that would putOccupied Heating above Occupied Cooling, the OccupiedCooling setting will change to stay above the heating set-point.
Occupied Heating Setpoint - (68°F) - This value is theOccupied Heating Setpoint. It is used only in CV mode ofoperation. Its relationship to the related setpoints is asdefined in the Unoccupied Heating Setpoint paragraphabove.
Unoccupied Cooling Setpoint - (85°F) - This value is theUnoccupied Cooling Setpoint. It is used in both CV and VAVmode of operation (in VAV, it controls Unoccupied coolingwith a Space Sensor).
Occupied Cooling Setpoint - (72°F) - This value is theOccupied Cooling Setpoint. It is used only in CV mode ofoperation. Its relationship to the related setpoints is asdefined in the Unoccupied Heating Setpoint paragraphabove.
[Input] FSI (Hot Water Freeze Protection) - (OFF) - Thisoption is used only on rooftop units with hydronic heat(Hydronic Heat Option is turned ON). Freeze protectionshould always be placed on units that use hydronic heating.When the control senses 24VAC, the control will turn on theHot Water valve to 100%. The control will continue to drivethe valve at 100% until five minutes after the switch hasopened. Then the valve will revert to normal operation. If thecontrol is operating the Fan, it will close the Economizer fullyuntil the freeze condition is over. If the fan is off and the RATdrops below 40°F, the Hot Water Valve will turn on 100%.
FIGURE 35 -SEQUENCE OF SETTING THE SET POINTS
UnOcc.
Htg.
Occ.
Htg.
UnOcc.
Clg.Occ.
Clg.
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Supply AirTemp (SAT) Alarm Setpoint for Cooling - (0°F) -If the SAT does not drive below this setpoint when all stagesof compression are operating and 10 minutes has elapsedsince the last compressor was energized, the control willdeclare a Cooling SAT Failure Alarm.
The alarm is written to the Error History Buffer. In networkedapplications, the alarm flag is readable by the network.
The alarm will reset automatically if the SAT does decreasebelow the setpoint (the alarm condition no longer exists), orwhen a compressor is turned off (the control does not requestall compressors operate). The SAT Alarm Setpoint for Cool-ing can be adjusted from 50°F - 80°F. If the value is set to 0°F(default) this feature is disabled.
Before the control declares an error, it will read the OAT andthe Economizer position. If the OAT is more than 20°Fwarmer than the setpoint and the Economizer is open morethan 20%, the control will close the Economizer for 10 min-utes and then read the SAT. If the SAT falls below the set-point, the control will declare an Economizer MinimumPosition alarm. The control will keep the Economizer closedand finish the Cooling mode. After the Cooling mode hasbeen satisfied, the control will move the Economizer back tothe minimum position.
Supply Air Temp (SAT) Alarm Setpoint for Heating - (0°F) -The SAT must drive above this setpoint when all stages ofheating are operating and 10 minutes has elapsed since thelast stage was energized. If this does not happen, the controlwill declare a Heating SAT Failure Alarm. The alarm is writtento the Error History Buffer. In networked applications, the alarmflag is readable by the network. The alarm will reset automati-cally if the SAT does increase above the setpoint (the alarmcondition no longer exists), or when a heating stage is turnedoff (the control does not request all heat stages to operate).
The SAT Alarm Setpoint for Cooling can be adjusted from70°F - 120°F. If the value is set to 0°F (default) this feature isdisabled.
Before the control declares an error, it will read the OAT andthe Economizer position. If the OAT is more than 20°F colderthan the setpoint and the Economizer is open more than20%, the control will close the Economizer for 10 minutes andthen read the SAT. If the SAT rises above the setpoint, thecontrol will declare an Economizer Minimum Position alarm.The control will keep the Economizer closed and finish theHeating mode. After the Heating mode has been satisfied,the control will move the Economizer back to the minimumposition.
Unoccupied Override Time Period - (60 min) - The Unoc-cupied Override Time Limit function will determine how longthe unit will operate in the Unoccupied Override mode whenthe Override button is pressed on the Space Sensor.
Once the Unoccupied Override mode is initiated, it will con-tinue until the programmed Unoccupied Override Time Limitis reached. The Override mode can not be cancelled by, forexample, a change of state of the Occupied input to ON(occupied) and then back to OFF (unoccupied).
This parameter is adjustable from 0 to 240 minutes. Thedefault is 60 minutes.
Fan Delays (ON) & (OFF) - Any time the control starts acompressor it will load the Fan On Delay for Cool with theprogrammed value. Any time the control turns off all the com-pressors it will load the Fan Off Delay for Cool with the pro-grammed value.
When the control turns on a gas heat stage, it will begin mon-itoring the gas valve and load the Fan On Delay For Heat withthe programmed value when it senses gas valve voltage.
When the thermostat terminates the call for W1 the controlwill turn off H1 output and load the Fan Off Delay for Heatwith the programmed value.
After the control has turned on heat, it will start monitoring theGas Valve. If at any time the Gas Valve (24 VAC) is notpresent for five minutes while H1 is on, the control will flag anAlarm. Anytime GV1/H1 goes off during the fan on delay, thecontrol will force the fan on, for the fan off delay period. Thecontrol will wait for GV1 to be on at least 15 seconds beforeforcing the fan on. If GV1 has been on for at least 15 sec-onds, and then goes away before the Fan On Delay has fin-ished, the fan will turn on anyway far a length of time equal tothe Fan Off Delay period.
If the control senses this input along with a Y signal, it will notturn on the compressors and it will run the Heating mode.Heating takes priority.
Fan ON Mode with the Sensor Option - (ON) - When thisoption is turned ON, the supply fan will continue runningwhen the zone sensor based temperature control is satisfied.This option applies only in systems using a zone sensor andonly in Occupied mode. With this option turned OFF, or inUnoccupied mode, the fan will go off when the zone sensorbased temperature control is satisfied and will go on onlywhen there is a call for heating or cooling. Turning this optionON is an equivalent of selecting fan ON (rather than AUTO)in systems with a thermostat. In a thermostat system, the fancontrol follows the thermostat's G signal. In sensor systemsand in the Occupied mode, the fan control follows the FanON Mode option.
Space Sensor Enable - (OFF) (INTERNALLY SET) - Thecontrol will use this input if it detects the device.
RAT Sensor Enable - (OFF) (INTERNALLY SET) - The con-trol will use this input if it detects the device.
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Demand Ventilation (ON) - Setting this parameter on tellsthe control to expect a signal from a 0-10VDC CO2 sensor.The default setting for CO2 is 1,000 ppm.
Demand Ventilation Setpoint - (1000 ppm) - This Setpointis the maximum Indoor Air Quality (IAQ) level that the controlwill allow. It is adjustable from 700 ppm to 1500 ppm.
IAQ Sensor Range - (5,000 ppm) - This tells the controlwhat the full range is for a specific IAQ sensor. It can bechanged from 0 to 10,000 ppm.
Cooling Mode Enable (ON) - This tells the control if it hasCooling Available (Mode Switch). If this option is turned off,cooling operation is disabled. Note that this parameter doesnot affect cooling operation in Comfort Ventilation mode.
Heating Mode Enable - (ON) - This tells the control if it hasHeating Available (Mode Switch). If this option is turned off,heating operation is disabled. Note that this parameter doesnot affect heating operation in Comfort Ventilation mode.
Space Setpoint Offset - (3°F) - The Space Setpoint Offset isthe +/- value the control will use to offset the Space Setpointwhen the slidebar Space Sensor is used. For example, if theSpace Setpoint Offset value is set to 3.0°F, shifting the slide-bar all the way in minus direction will decrease the SpaceSetpoint by 3.0°F and shifting it all the way in plus directionwill increase the Space Setpoint by 3.0°F. It is adjustable from0°F to 5°F.
ASCD Override - This is not an option parameter but rather aone-time command issued by pressing the Test / Reset / Upbutton pressed and released within five seconds; the ASCD’swill be set to zero for one cycle.
Run Test (Commissioning Test) - This is not an optionparameter but rather a one-time command, activated by set-ting parameter 1 ON.
When the Run Test command is issued, the control will shutthe unit down if it is running and then start a Run testsequence:
1. Turn on the Fan and then turn on all the compressors, one at a time, with a 15-second delay between them. Condenser fan #1 turns on with compressor #1, con-denser fan #2 turns on with compressor #2. After the last compressor has been turned on, the control will run the compressors for the programmed minimum run time and then turn them all off. Condenser fans are also turned off.
2. The control will then turn on the Heat stages, one at a time, with a 15 second delay between them. The control will run each Heat stage for three minutes and then turn all the Heat off.
3. The control will then open the Economizer to the 100% open position and wait five minutes before closing it to the Minimum Position. When the economizer is at 100%, the exhaust damper will be open to 100% and the exhaust fan runs for 5 minutes, then shuts down.
4. During this Run Test operation the control will read all the installed sensors and verify that their readings are good. If any error is detected the control will display the appro-priate error. During the Run Test, the supply fan contin-ues to be monitored via the Air Proving Switch, and a fan failure will cause a unit shutdown.
After the control is finished with the Run Test the normal oper-ation will resume. This command is a good method to use toensure the control is operating and all input and output pointsare functional.
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TABLE 52: SETTABLE SYSTEM PARAMETERSADDRESS FUNCTION UNIT RANGE DEFAULT YOUR SETTINGS
1 Run test ON-OFF OFF
2 Fan on delay-Heating Sec 0-30 30
3 Fan off delay-Heating Sec 0-255 60
4 Fan on delay-Cooling Sec 0-30 0
5 Fan off delay-Cooling Sec 0-255 30
6 Factory setting - - 1 Do not change
7 Suspend Cont Fan when starting Heating ON-OFF OFF
8 Factory setting - ON-OFF 0 Do not change
9 Unoccupied Override Time Period Minutes 0-240 60
10 Occupied Cooling Setpoint Degrees 45-99 72
11 Occupied Heating Setpoint Degrees 45-99 68
12 Unoccupied Cooling Setpoint Degrees 45-99 85
13 Unoccupied Heating Setpoint Degrees 45-99 60
14 SAT Control-Cooling ON-OFF ON-OFF ON
15 Cooling SAT Control Setpoint Degrees 40-65 50
16 SAT Control for Heating ON-OFF ON-OFF ON
17 Heating SAT Control Setpoint Degrees 100-180 135
18 Hydronic Heating ON-OFF ON-OFF OFF
19 First Stage Hydronic Heating SAT Setpoint Degrees 80-180 120
20 Second Stage Hydronic Heating SAT Setpoint Degrees 80-180 150
21 Hydronic Heating Reverse Actuated Valve ON-OFF ON-OFF OFF
22 Remote Control ON-OFF ON-OFF OFF
23 VAV Upper Cooling SAT Degrees 40-70 60
24 VAV Lower Cooling SAT Degrees 40-70 55
25 VAV SAT Reset Setpoint Degrees 40-85 72
26 VAV Occupied Setpoing ON-OFF ON-OFF OFF
27 VAV Occupied Heating Degrees 40-85 68
28 VAV Stand Alone Operation ON-OFF ON-OFF ON
29 Morning Warm-Up RAT Degrees 50-85 70
30 Duct Static Setpoint " H2O 0 – 5” 1.5”
31 Building Pressure Setpoint " H2O neg .25 to .25 .1”
32 Economizer ON-OFF ON-OFF ON
33 Economizer First Stage Degrees 40-65 55
34 Economizer Second Stage Degrees 40-65 50
35 Economizer Minimum Position Percent 0 to 100% 20
36 Outside Air Humidity Sensor ON-OFF ON-OFF OFF
37 Economizer Outside Air Enthalpy Setpoint BTUs Per Pound Oct-50 27
38 Return Air Humidity Sensor ON-OFF ON-OFF OFF
39 Economizer OAT Enable Degrees 40-80 55
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40 Demand Ventilation ON-OFF ON-OFF OFF
41 IAQ Sensor Range PPM 0-5000 2000
42 Demand Ventilation Setpoint PPM 0-5000 1000
43 Power Exhaust ON-OFF ON-OFF ON
44 Modulating Exhaust ON-OFF ON-OFF OFF
45 Exhaust VFD Installed ON-OFF ON-OFF OFF
46 Exhaust Damper Position for Exhaust Fan to Turn On (Modulating Only) % Of Damper Position 0-100 80%
47 Exhaust Damper Position for Exhaust Fan to Turn Off (Modulating Only) % Of Damper Position 0-100 20%
48Economizer Damper Position for
Exhaust Fan to Turn On (Non-Modu-lating Only)
% Of Damper Position 0-100 60%
49Economizer Damper Position for
Exhaust Fan to Turn Off (Non-Modu-lating Only)
Percent of Economizer Position 0-100% 20%
50 APS Data Open-Closed Open-Closed Open
51 Dirty Filter Switch ON-OFF ON-OFF OFF
52 Dirty Filter Switch Data Open-Closed Open-Closed Open
53 Cooling Mode Enable ON-OFF ON-OFF ON
54 Heating Mode Enable ON-OFF ON-OFF ON
55 Fan On Mode with the Sensor Option ON-OFF ON-OFF ON
56 Space Setpoint Offset Degrees -5 to 5 0 degrees
57 Metric Operation ON-OFF ON-OFF OFF
58 BAS Economizer ON-OFF ON-OFF OFF
59 Year Year 00-99 4
60 Month Month Number 1
61 Day of Month Day Number 1
62 Day of Week Day Number 1
63 Hour Hour 0-23 0
64 Minute Minutes 0-59 0
65 SAT (Supply Air Temp) Degrees -40 to 180 Read Only Read Only
66 RAT (Return Air Temp) Degrees -40 to 180 Read Only Read Only
67 OAT (Outside Air Temp) Degrees -40 to 180 Read Only Read Only
68 ST (Space Temp) Degrees -40 to 180 Read Only Read Only
69 OAH (Outside Air Hum) %RH 0 to 100% Read Only Read Only
70 RAH (Return Air Hum) %RH 0 to 100% Read Only Read Only
71 Occupied Input Enable ON-OFF ON-OFF OFF
72 Alarm Array
These values represent the last 5 alarm codes in memory. 72 is latest & 76 oldest.
Read Only Read Only
73 Alarm Array Read Only Read Only
74 Alarm Array Read Only Read Only
75 Alarm Array Read Only Read Only
76 Alarm Array Read Only Read Only
77 CV/VAV Mode Read Only Flag CV=0 VAV=1 Read Only Read Only
78 Hot Gas Reheat ON-OFF ON-OFF OFF
TABLE 52: SETTABLE SYSTEM PARAMETERS (Continued)ADDRESS FUNCTION UNIT RANGE DEFAULT YOUR SETTINGS
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NOTES:For On/Off functions, 1 is ON and 0 is OFFRead only items are readings from sensors which only change as the measured condition changes.
SERVICE
REFRIGERATION SYSTEM
CHARGE: Each system is fully factory charged with R-22.The correct charge appears on the unit nameplate.
Thermal Expansion Valves: The 30 ton unit has 3 and the 40ton unit has 4 independent refrigeration systems. TheseTXVs are set to maintain 15°F superheat leaving the evapo-rator coil. The superheat on each valve is adjustable, how-ever, adjustments should only be made if absolutelynecessary.
MOISTURE/LIQUID SIGHT GLASS: Each system has amoisture/liquid sight glass. These are located on the liquidlines in the condenser section.
A clear flow of liquid indicates the unit is properly charged.Any bubbles indicates the system is undercharged or non-condensables may exist. Corrective action should be taken.
A change in color of the moisture indicator shows the approx-imate moisture content of the system in parts per million. Ifmoisture is indicated, corrective action should be taken.
FILTER DRIER: Each system is equipped with a filter drier.The drier should be replaced whenever moisture is indicatedin the system.
COMPRESSORS
Each compressor is inherently protected from over currentand over temperature. High and low pressure switches areinstalled on the discharge and suction lines respectively forhigh and low pressure protection. Scroll compressors operatein only one direction. If the compressor is experiencing lowamperage draw, similar discharge and suction pressure orincreased noise level, it is operating in reverse. Switch twoline voltage connections to correct (See Compressor Rotationpage 63).
MOTORS
INDOOR BLOWER MOTORS
All indoor blower motors are non-inherently protected threephase motors. Overcurrent protection is provided by a man-ual reset starter/overload relay and short circuit protection isprovided by fuses.
POWER EXHAUST OR RETURN AIR FAN MOTORS
All motors are non-inherently protected three phase motors.Overcurrent protection is provided by a manual resetstarter/overload relay and short circuit protection is providedby fuses.
CONDENSER FAN MOTORS
All condenser fan motors are inherently protected threephase motors. Short circuit protection is provided by fuses.
DRAFT MOTOR (GAS FURNACE)
All draft motors are line voltage, inherently protected, singlephase PSC motors. Short circuit protection is provided byfuses.
79 Hot Gas Bypass ON-OFF ON-OFF OFF
80 Duct Static Reading Inches Water 0 to 5.0” Read Only Read Only
81 Building Pressure Reading Inches Water 0 to 5.0” Read Only Read Only
82 Number Of Compressors Number 1 to 4 Factory Set
83 Number Of Heating Stages Number 1 to 3
TABLE 52: SETTABLE SYSTEM PARAMETERS (Continued)ADDRESS FUNCTION UNIT RANGE DEFAULT YOUR SETTINGS
TABLE 53: SYSTEM MOISTURE INDICATOR
INDICATOR COLOR 75° 100° 125°
Green (Dry) Below 30 Below 45 Below 60
Chartreuse 30 - 90 45 - 130 60 - 180
Yellow (Wet) Above 90 Above 130 Above 180
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TABLE 54: STEAM COIL (1 ROW, 25 & 30 TON)1
1. Based on 60°F entering air temperature, 2.00” maxi-mum air pressure drop across the coil.
CFMCapacity (MBH) at Steam Pressure (PSI)
2 6 10 15
6000 194.1 207.9 219.8 232.6
8000 221.1 236.9 250.4 265.0
10000 243.2 260.5 275.4 291.4
12000 261.9 280.6 296.6 313.9
15000 285.6 306.0 323.5 342.4
TABLE 55: STEAM COIL (1 ROW, 40 TON)1
1. Based on 60°F entering air temperature, 2.00” maxi-mum air pressure drop across the coil.
1. Based on 60°F entering air temperature, 2.00” maximum pressure drop across the hot water coil.
GPM CFM
Capacity (MBH) at Entering Water Temperature
140 °F 160 °F 180 °F 200 °F
10
6000 91.4 115.3 139.3 163.6
8000 102 128.8 155.8 182.9
10000 110.4 139.5 168.8 198.4
12000 117.3 148.4 179.6 211.2
15000 125.9 159.2 192.9 226.9
20
6000 103 129.4 156 182.7
8000 116.8 147 177.2 207.7
10000 128.2 161.3 194.7 228.2
12000 137.8 173.6 209.5 245.6
15000 150 189 228.2 267.8
30
6000 107.6 135 162.5 190.1
8000 122.8 154.3 185.8 217.5
10000 135.5 170.3 205.1 240.2
12000 146.4 184 221.8 259.7
15000 160.3 201.6 243 284.8
40
6000 110.1 138 166 194.1
8000 126.1 158.2 190.5 222.8
10000 139.6 175.2 210.9 246.8
12000 151.2 189.8 228.5 267.5
15000 166.1 208.6 251.3 294.1
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TABLE 59: HOT WATER COIL (1 ROW, 40 TON)1
1. Based on 60°F entering air temperature, 2.00” maximum pressure drop across the hot water coil.
GPM CFM
Capacity (MBH) at Entering Water Temperature
140 °F 160 °F 180 °F 200 °F
10
8000 102 128.8 155.8 182.9
11000 114 144.1 174.4 205.1
14000 123.2 155.9 188.8 222.1
17000 130.6 165.4 200.4 235.8
20000 136.8 173.3 210.1 247.3
20
8000 116.8 147 177.2 207.7
11000 133.2 167.7 202.3 237.2
14000 146.2 184.2 222.4 260.8
17000 157 197.9 239 280.5
20000 166.2 209.6 253.2 297.3
30
8000 122.8 154.3 185.8 217.5
11000 141.2 177.4 213.8 250.3
14000 155.9 196.1 236.4 276.9
17000 168.3 211.8 255.4 299.3
20000 179.1 225.3 271.8 318.6
40
8000 126.1 158.2 190.5 222.8
11000 145.6 182.7 220 257.5
14000 161.4 202.6 244.1 285.8
17000 174.7 219.5 264.5 309.7
20000 186.3 234.2 282.3 330.6
TABLE 60: WATER PRESSURE DROP (1 ROW, 25 & 30 TON)
GPM 10 20 30 40
Water Pressure
Drop0.9 3.0 6.0 10.0
TABLE 61: WATER PRESSURE DROP (1 ROW, 40 TONS)
GPM 10 20 30 40
Water Pressure
Drop0.9 3.0 6.0 10.0
TABLE 62: HOT WATER COIL (2 ROW, 25 & 30 TON)1
1. Based on 60°F entering air temperature, 2.00” maximum pressure drop across the hot water coil.
GPM CFM
Capacity (MBH) at Entering Water Temperature
140 °F 160 °F 180 °F 200 °F
20
6000 177.5 223.8 270.4 317.3
8000 203.8 257.2 311.1 365.5
10000 224.8 284.1 343.9 404.2
12000 242.2 306.4 371.1 436.4
15000 263.6 333.8 404.6 476.1
40
6000 198.1 248.9 300.0 351.3
8000 232.2 292.0 352.2 412.7
10000 260.7 328.1 395.9 464.1
12000 285.0 359.0 433.4 508.3
15000 316.0 398.4 481.3 564.8
60
6000 206.1 258.7 311.4 364.2
8000 243.6 305.9 368.4 431.1
10000 275.3 345.9 416.8 488.0
12000 302.9 380.7 458.9 537.6
15000 338.4 425.7 513.4 601.7
80
6000 210.5 263.9 317.4 371.1
8000 249.8 313.3 377.1 441.1
10000 283.3 355.6 428.2 501.0
12000 312.7 392.7 473.0 553.6
15000 351.0 440.9 531.3 622.1
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NOTE: Water pressure drop numbers are based on 60°Fentering air temperature, 2.00” maximum air pres-sure drop across the hot water coil(s). ARI certifiedratings at covering other conditions are availableupon request. Hot water coils are approved for usewith glycol (rates available upon request.
TABLE 63: WATER PRESSURE DROP (2 ROW, 25 & 30 TON)
GPM 20 40 60 80
Water Pressure
Drop0.9 3.0 6.0 10.0
TABLE 64: WATER PRESSURE DROP (2 ROW, 40 TON)
GPM 20 40 60 80
Water Pressure
Drop0.9 3.0 6.0 10.0
TABLE 65: STATIC RESISTANCE HOT WATER COIL (25 & 30 TON)
CFM 6000 8000 10000 15000
Air Pressure Drop 1 Row 0.07 0.11 0.16 0.32
Air Pressure Drop 2 Row 0.14 0.23 0.33 0.65
TABLE 66: STATIC RESISTANCE HOT WATER COIL (40 TON)
CFM 8000 11000 14000 20000
Air Pressure Drop 1 Row 0.11 0.19 0.29 0.52
Air Pressure Drop 2 Row 0.23 0.39 0.58 1.06
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FIGURE 36 - HOT WATER COIL - 25 & 30 TON, 1 ROW, AT 10 GPM
Combustion air proving is provided by a pressure switch. Asthe motor approaches full speed, this switch closes beforeany other circuit or gas component can be energized.
ROLLOUT
Rollout protection is provided by a switch mounted on theheat shield of each furnace module. The switch senses anyflame or excessive heat in the burner compartment. Whenthe switch opens, the furnace module is immediately lockedout until there is a break in power to the specific furnace mod-ule and the manual itch is reset. Note that only the modulewith the open rollout switch will be locked out, the remainingmodules will continue to operate although all should beinspected.
A trip of the rollout switch likely indicates a flue restriction, anopening in the flue passageway, defective pressure switch ora loose combustion blower wheel. Corrective action shouldbe taken accordingly.
MAINTENANCE
NORMAL MAINTENANCE
Periodic maintenance normally consists of changing or clean-ing filters and (under some conditions) cleaning the mainburners.
FILTERS
Inspect once a month. Replace disposable or clean perma-nent type as necessary. The dimensional size of the replace-ment filter must be the same as the replaced filter (Refer toTable 11).
MOTORS
Outdoor fan motors are permanently lubricated and requireno maintenance. Lubrication, if desired, is to be performed bya qualified service agency.
Ventor motors are factory lubricated for an estimated 10-yearlife.
Indoor Fan Motors - The indoor blower motor features ball-bearings that do not require periodic lubrication. Periodiclubrication of the motor bearings can extend the life but isoptional.
To go to bypass mode, the bypass VFD as installed in thisunit must be switched by hand on the front of the bypassenclosure in the fan cabinet of the rooftop unit. It does notautomatically go to bypass mode if the drive fails.
The switches on the front of the bypass box control its runmode. For normal running:
• The ON/OFF rotary power switch must be in the ON position.
• The BYPASS/OFF/DRIVE switch S1 should be in the DRIVE position.
• The HAND/STOP/AUTO switch S2 should be in the AUTO position, so that the unit control will properly run the fan and control the speed.
• The TEST/NORMAL switch S3 should be in the NOR-MAL position.
If the drive fails:
• Switch the BYPASS/OFF/DRIVE switch to BYPASS. If there is a call for the fan, it will go to full speed.
• If there are VAV boxes, connect them to the circuit at TB1/6 and they will be driven open in bypass mode.
Prior to any of the following maintenance proce-dures, shut off all power to the unit. Failure to doso could cause personal injury.
Label all wires prior to disconnection when servic-ing controls. Wiring errors can cause improper anddangerous operation. Verify proper operation afterservicing.
Damage can occur if the bearings are over lubri-cated. Use grease sparingly.
Perform all maintenance operations on the blowermotor with power disconnected from the unit. Donot attempt to lubricate bearings with the unit inoperation.
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On an annual basis, check the motor for accumulations ofdust, etc. That may block the cooling slots in the motor shell.Check for loose, damaged or misaligned drive components.Check that all mounting bolts are tight. Replace defectiveparts as required.
If desired, every three years remove both pipe plugs at eachend shell and clean out any hardened grease or foreign mat-ter. Replace one plug on each end with a clean grease fitting.Using a low pressure grease gun, pump grease (ChevronSRI-2 or equivalent) into the bearing cavity until new greaseshows at the open port. Do not over-lubricate. Run the motorfor ten minutes until excess grease is purged from the cavity.Replace the plugs.
FAN DRIVES
Units are supplied with fan shaft bearings that do not requiremaintenance but may be relubricated per Table 67.
Lubricate with a premium quality NLGI 2 grade multi-purposeroller bearing grease having corrosion inhibitors, anti-oxidantadditives and mechanical stability for high speed operation.The grease should also have a minimum base oil viscosity of500 SUS at 100°F. Do not use a heavy, long fibered grease.
The presents of dirt, moisture or chemical fumes around thebearings requires more frequent lubrication.
Fill bearings with lubricant prior to extended shutdown or stor-age. Rotate the shaft monthly during idle periods.
Avoid excessive grease purging from seals during lubrication,this reduces the life of the bearing.
OUTDOOR COIL
Dirt should not be allowed to accumulate on the outdoor coilsurface or other parts in the air circuit. Cleaning should be asoften as necessary to keep coil clean. Use a brush, vacuumcleaner attachment, or other suitable means. If water is used
to clean coil, be sure power to the unit is shut off prior tocleaning.
NOTE: Exercise care when cleaning the coil so that the coilfins are not damaged.
Do not permit the hot condenser air discharge to beobstructed by overhanging structures or shrubs.
GAS BURNER
Periodically (at least annually at the beginning of each heat-ing season) make a visual check of the main burner flame. Ifnecessary, adjust main burner primary air shutters to give adistinct, sharp blue flame as explained under BURNERINSTRUCTIONS.
TO CLEAN BURNERS
Remove them from the furnace as explained in BURNERINSTRUCTIONS. Clean burners with hot water applied alongtop of the burner.
COMBUSTION AIR DISCHARGE
Visually inspect discharge outlet periodically to make surethat the buildup of soot and dirt is not excessive. If necessary,clean to maintain adequate combustion air discharge.
CLEANING FLUE PASSAGES AND HEATING ELEMENTS
With proper combustion adjustment, the heating element of agas fired furnace will seldom need cleaning. If the elementshould become sooted, it can be cleaned as follows:
1. Remove the burner assembly as outlined in BURNER INSTRUCTIONS.
2. Remove the screws holding the top of the flue collector box. Carefully remove the top of the flue collector box. The draft wheel, housing, and draft motor can remain assembled to the flue box top, if cleaning of these com-ponents is not required.
3. This will provide access to flue baffles, then remove the flue baffles from the tube interiors. To remove, the flue baffles, remove the stainless steel screws from the vest panel. Refer to Figure 57.
4. Using a wire brush on a flexible wand, brush out the inside of each heat exchanger from the burner inlet and flue outlet ends.
5. Brush out the inside of the flue collector box, and the flue baffles.
6. Run the wire brush down the vent hoods from the flue collector end.
7. If soot build-up is particularly bad, remove the vent motor and clean the wheels and housings. Run the wire brush
down the flue extension at the outlet of the vent hous-ings.
8. After brushing is complete, blow all brushed areas with air or nitrogen. Vacuum as needed.
9. Replace parts in the order they were moved in steps 1 to 4.
10. Assure that all seams on the vent side of the combustion systems are air tight. Apply a high temperature (+500°F) sealing compound where needed (Dow Corning, Silastic 736, Loctite Superflex 596 or equivalent).
The restrictor plate must also be sealed to furnace tube sheet.
SECURE OWNERS APPROVAL
When the system is functioning properly, secure the owner’sapproval. Show him the location of all disconnect switchesand the room temperature sensors. Teach him how to startand stop the unit and how to adjust the temperature settingswithin the limitations of the system.
