Telstra 007 Doc Current

TELSTRA CORPORATION LIMITED (ABN 33 01 775 556) | ISSUED: 9 MAY. 2011

FINAL | TELSTRA UNRESTRICTED | 007338 E10-2 |ISSUE NUMBER: 1.0

AUTHOR‟S NAME: MICHAEL WILLIAMS

BUSINESS UNIT: TELSTRA OPERATIONS

SUB BUSINESS UNIT: NETWORKS AND ACCESS TECHNOLOGIES

ISSUE DATE: 9 MAY. 2011| ISSUE NUMBER: 1.0

DOCUMENT NO: 007338 E10-2

INNOTECH DDC APPROVED CONTROL STRATEGY

BUILDING SERVICES

007338 - Power & Engineering Services

DESIGN STANDARD

SUB DOMAIN: BUILDING SERVICES

This Power & Engineering Services document is to be used by network designers and

constructors to design and install infrastructure approved for Network under 007338 Part

D and in accordance with the deployment criteria specified in 007338 Part C in order to

meet Telstra‟s Business Objectives.

SUMMARY: The Purpose of this document is to provide a framework for programmers of

Innotech Direct Digital Controls (DDC) which details the minimum requirements for

functions and concepts to be incorporated and how those functions are to be programmed

in a standard manner.

VERSION LABEL: Final

SECURITY CLASSIFICATION: Telstra Unrestricted

TELSTRA CORPORATION LIMITED (ABN 33 051 775 556) | ISSUED: 9 MAY. 2011 PAGE 2 OF 16

FINAL | TELSTRA UNRESTRICTED | 007338 E10-2 | ISSUE NUMBER: 1.0

TABLE OF CONTENTS

1. PURPOSE ....................................................................................................................... 3

2. SCOPE........................................................................................................................... 3

3. KEY STAKEHOLDERS....................................................................................................... 3

4. PROGRAMMING FUNCTIONAL REQUIREMENTS .................................................................. 4

4.1. GENERAL ................................................................................................................ 4

4.2. HVAC ENABLE.......................................................................................................... 4

4.3. TEMPERATURE CONTROL .......................................................................................... 5

4.4. ECONOMY CYCLE ..................................................................................................... 6

4.4.1. ECONOMY CYCLE ENABLE – ENTHALPY .......................................................... 6

4.4.2. ECONOMY CYCLE ENABLE – SENSIBLE TEMPERATURE ..................................... 7

4.4.3. ECONOMY CYCLE CONTROL .......................................................................... 8

4.5. SENSOR ALARMS ..................................................................................................... 9

4.6. COMFORT CONTROLLED AREAS............................................................................... 10

4.7. HEATING CONTROL ................................................................................................ 10

4.8. FAULT HANDLING .................................................................................................. 10

4.9. WATCH PAGES ...................................................................................................... 10

4.10. DATA LOGGING ..................................................................................................... 11

4.11. LEAD / LAG AND DUTY / STANDBY CHANGEOVER ..................................................... 12

5. APPROVED SOFTWARE AVAILABILITY ............................................................................. 13

6. APPLICATION RULES ..................................................................................................... 14

7. REFERENCES ............................................................................................................... 14

7.1. 007338 ................................................................................................................. 14

7.2. OTHER INTERNAL .................................................................................................. 14

7.3. EXTERNAL ............................................................................................................. 14

8. DEFINITIONS ............................................................................................................... 14

9. ATTACHMENTS ............................................................................................................. 15

10. DOCUMENT CONTROL SHEET ........................................................................................ 16

PAGE 3 OF 16 TELSTRA CORPORATION LIMITED (ABN 33 051 775 556) |ISSUED: 9 MAY. 2011


1. PURPOSE

The Purpose of this document is to provide a framework for programmers of Innotech Direct

Digital Controls (DDC) which details the minimum requirements for functions and concepts to

be incorporated and how those functions are to be programmed in a standard manner.

2. SCOPE

This document applies to all new Innotech DDC control strategies. Individual site and HVAC

plant specific requirements may necessitate the addition of some functions such as lead / lag

changeovers etc., however, the programming methodology, minimum required functions and

standard “look and feel” should not require significant change. Retro upgrading of existing

DDC programs should be considered at such times when this can be undertaken cost

effectively. Note that in some cases existing older controls and system resources may not

allow for full retro implementation.

The document uses hyperlinks and colour.

3. KEY STAKEHOLDERS

The following stakeholders (listed alphabetically) have reviewed and agreed to the content of

this document before issue:

NAME TITLE

George Bakogianis Senior Capacity Planner, Network Planning Studies, Telstra

Chris Baran-Kamp 007338 Technical Editor - Network & Facilities Mgmt, Telstra

George Bradilovic General Manager – Network and Facilities Management, Telstra

Greg Dendle Senior Technology Specialist, Building Network Design, Telstra

Pat Fitzgerald Strategic Facilities Mgmt, Network Services, Telstra

Allan Gontar National Energy Manager – Telstra Property

Mark Kelly Snr Capacity Planner Network Standards & Compliance, Telstra

Anthony Price Strategic Planning Manager, Network Group, Telstra Property

David Roach Technology Team Manager – Power, Telstra

Ron Roberts National Contract & Service Mgr, Network & IT Ops, Telstra

Aurecon (Represented by Paul Brown)

Silcar (O&M) (Represented by G. McIntyre)

Silcar (D&C) (Represented by G. Mullen)

Table 1: Key Stakeholders



4. PROGRAMMING FUNCTIONAL REQUIREMENTS

4.1. GENERAL

For conceptual illustration, the control system described is based on a networkable Direct

Digital Controller (DDC) serving a 4 stage HVAC system with Economy Cycle Cooling (ECC).

This control strategy concept can be applied to other DDC systems and plant configurations.

Where Economy Cycle Cooling is not employed, the description of mechanical cooling control

is still applicable and can be adapted to systems incorporating fewer or greater than four

cooling stages as described here.

Some functions included for illustration (such as Fire and VESDA status inputs and alarms)

may be applicable to specific projects or required by regulatory code or Telstra Standards on

an individual installation basis. Where these functions are not required by specification they

should be deleted from the final control strategy. Ensure all control strategies are compliant

with Fire & VESDA standards C9-2 & E10-1.

Note that all program blocks are to be discretely named and a printed copy of the „as

installed‟ control program, block details and wiring diagram must be included in O&M

manuals.

Text blocks should be used to label programming functions and provide detail regarding any

variation to standard such as inclusion of time delays etc.

4.2. HVAC ENABLE

Generally, the Air-conditioning Unit will run continuously. A Master On/Off switch accessed

via the front panel of the Controller (Watch page 1) can be used to stop the unit from

running. An airflow switch in the supply air ductwork confirms the supply air fan status. Once

the fan is requested and the status is confirmed as running, the automatic control functions

are enabled (Control Enable). If the fan status is lost, the control functions are disabled. If

the supply air fan is called to run and no fan status has been received by the duct mounted

air-flow switch after a 60 second delay period, a Supply Air Fan fault will be displayed on the

LCD of the Controller. This fault will be displayed as SAF Fault.



Figure 1: HVAC Enable Logic Diagram

4.3. TEMPERATURE CONTROL

If the automatic control functions are enabled, the controller responds to its discrete

temperature sensor (or the averaged value or high signal select input as appropriate where

multiple sensors are specified and installed) to maintain a target long term average room

temperature of 250C.

As the space temperature rises above a nominal 24.50C set-point, the four compressors will

be cycled through a single Cooling PID loop with a nominal proportional band of 2.50C. For all

cases Integral and Derivative values will both be 0%

Individual Hysteresis blocks and values as below are provided for each cooling stage. With

nominal set-point and proportional band values as above, the four compressors will be cycled

in the following manner to maintain conditions –

i. Compressor 1 On – 25.1ºC (25% output) Off - 24.6ºC (5% Output)

ii. Compressor 2 On - 25.7ºC (50% Output) Off - 25.1 ºC (25% Output)

iii. Compressor 3 On - 26.3ºC (75% Output) Off - 25.7ºC (50% Output)

iv. Compressor 4 On - 26.8ºC (95% Output) Off - 26.3ºC (75% Output)

Figure 2: Temperature Control Compressor Cycling

Time delay blocks are not incorporated into the temperature controlled cooling sequence

unless these are a necessary replacement for absent electrical / mechanical start delay or

short cycle timers within the HVAC plant.

For systems incorporating fewer or greater than 4 stages, the above staging schedule and

proportional band should be amended as required to maintain an average long term

temperature of 250C while maintaining the main control point values e.g. 2 stage cooling –

Compressor 1 on at 50% output and Off at 5% output, Compressor 2 On at 95% output and

Off at 50% output.

Limits are placed on the User Temperature Set-point so this cannot be adjusted below 24ºC

or above 28ºC.

For maintenance purposes a “Unit Test Mode” soft switch (User Variable) is provided via

Watch Page 1, which operates the plant at a reduced control set-point between 18°C and

22°C (User adjustable) for a set time of 20 minutes.

TEMPERATURE

24.5°C 25°C 25.5°C 26°C 26.5°C 27°C

(C1 on)

(C2 off)

(C2 on)

(C3 off)

(C3 on)

(C4 off)

(C4 on)

(C1 off)

OUTPUT



Figure 3: Temperature Control Logic Diagram

Figure 4: Temperature Control Test Logic Diagram

4.4. ECONOMY CYCLE

4.4.1. ECONOMY CYCLE ENABLE – ENTHALPY

(Where specified for inclusion)

The Economy Cycle is enabled by an Enthalpy Comparator mode. If the Ambient Enthalpy is

1 KJ/Kg below the Return Air Enthalpy the economy cycle will be enabled to operate. If the

Ambient Enthalpy rises to equal the Return Air Enthalpy then the Economy Cycle will be

disabled. Where specified, a VESDA or Fire Alert will inhibit operation of the economy cycle.

Further interlocks for the economy cycle to be enabled are as follows:

Ambient Humidity Low Limit > 20% High Limit < 80%

Ambient Temperature Low Limit >5ºC High Limit <25ºC

These operating parameters are established through the use of Hysteresis blocks.



Figure 5: Economy Cycle Enable (Enthalpy Comparison) Logic Diagram

4.4.2. ECONOMY CYCLE ENABLE – SENSIBLE TEMPERATURE

(Where specified for inclusion)

The Economy Cycle is enabled by a Temperature comparison mode. When the ambient

temperature is a minimum 1ºC below return air or conditioned space temperature the

economy cycle will be enabled to operate. If the ambient temperature rises to equal the

return air or conditioned space temperature then the Economy Cycle will be disabled. No

Relative Humidity sensing or limits are included in a sensible temperature enabled Economy

Cycle system.

Further interlocks for the economy cycle to be enabled are as follows:

Ambient Temperature Low Limit >5ºC High Limit <18ºC (to a maximum of 23 ºC in some

nominated colder climates)

These operating parameters are established through the use of Hysteresis blocks.



Figure 6: Economy Cycle Enable (Sensible Temperature) Logic Diagram

4.4.3. ECONOMY CYCLE CONTROL

(Enthalpy or Sensible temperature models)

When enabled by the above conditions, the economy cycle is ready to be controlled. If the

Return Air Temperature rises above a nominal set-point (named ECC Low Limit), of 20ºC the

economy cycle dampers will modulate through a proportional band of 3ºC. That is, at a room

temperature of 20ºC the ECC fresh air make-up and spill air dampers would have modulated

to the fully closed position with the return air damper fully open. At 23ºC the ECC fresh air

make up and spill air dampers would have modulated to the fully open position and return air

dampers would be fully closed.

Limits are placed on this Set-point (ECC Low Limit) so this cannot be adjusted below 18ºC or

above 20ºC.

The control strategy shall also include a Test Mode Function of 5 minutes duration operated

via a soft switch grouped with other ECC functions. This test mode will operate all ECC

dampers to their fully on position.

An automatic timer function (ECC Damper maintenance) will operate all ECC dampers to

their fully functioning positions each Monday from 2:00 am to 2:05 am. This is to reduce the

incidence of dampers seizing after long periods of inactivity.



Figure 7: Economy Cycle Control Logic Diagram

4.5. SENSOR ALARMS

If any outside air sensor output is below 1% or above 85% of normal full scale output and if

this condition is sustained for a continuous period of greater than 168 hours, a latched alarm

within the DDC is to output the warning “Check OA Sensor” to the display panel. This latched

alarm should not lock out the economy cycle as under some conditions e.g. prolonged rain

periods, a “false alarm” might be generated. The purpose of this flag alarm is to alert

maintenance operators that the outside air sensors should be checked for operation /

accuracy. A soft switch alarm reset must be provided within the DDC.

Figure 8: Ambient Conditions Logic Diagram



Figure 9: Ambient Sensor Fault Alarm Logic Diagram

4.6. COMFORT CONTROLLED AREAS

(Offices, Lunch rooms etc.)

Where controlled supply air dampers or stand alone HVAC plant are provided to office or

other areas conditioned for human comfort only, then for each independently conditioned

space, an “On/Off” user variable soft switch will be provided and HVAC will be enabled via

individual discrete time control functions activating operation during normal business hours

only (nominally 7:30 am – 5:00 pm Mon–Fri). A physical push button will be provided which

enables cooling for a 1 hour period outside normal business hours. A separate independent

cooling set point and PID block will be provided with a limited user input range of 23ºC to

28ºC. The controlled dampers or mechanical cooling will modulate though a 1 deg

proportional band.

4.7. HEATING CONTROL

In limited cases where heating is provided for human comfort in office spaces etc. for each

independent conditioned space, a “Heating Enable” on/off user variable soft switch will also

be incorporated. Heating will be controlled via a discrete time control block activating the

heating function during normal business hours only (nominally 7:30 am – 5:00 pm Mon –

Fri). A separate independent heating PID block will be enabled after confirmation of Supply

Air Fan Status (Control enable). The user input set-point range will be limited to 18ºC to

22ºC. Note that this provides a minimum 1ºC difference between the maximum heating and

minimum cooling independent set-points to avoid heat/cool conflicts.

4.8. FAULT HANDLING

System faults within the DDC should be logged and display if in alarm but should not latch

(with the exception described under Economy Cycle). DDC configurations should inhibit the

running of any component in fault condition but automatically reset when a fault clears

without requiring a hard reset. This does not apply to hardware faults such as HP/LP and

motor contactor overloads etc. Treatment of these faults should be specified elsewhere.

4.9. WATCH PAGES

The following system data is displayed via the DDC watch pages. Any repetitive display is

deliberate in order to maintain logical grouping of data. Flash page and Watch page 1 are

mandatory but some additions or deletions to subsequent pages may be necessary

dependant on the program configuration. The assignment of all data should follow a logical

grouping. Where a watch page is left totally blank through deletions then all subsequent

watch pages move up 1 designation. Typical Layout –

Flash Page –

Control Enable Status

Supply Fan Status

Return Air or Room Temp (Controlling temperature point)



Cooling Demand %

Economy Cycle Demand % (For ECC installed systems only)

Page 1 –

Master (Unit) On / Off switch ( User variable)

Test Mode Set-point ( User variable)

Test Mode On/Off (Cooling Test mode User Variable)

Return Air or Room Temp (Controlling temperature point)

Cooling Set Point (User variable)

Page 2 –

Cooling Demand %

Compressor or Cooling Stage 1 enable Status




Page 3 –

Outside Air Temp (For all ECC installed systems only)

Outside Air Humidity (For Enthalpy ECC installed systems only)

Outside Air Sensor Alarm reset (For all ECC installed systems only)

Return or Room Air Temp (Controlling temperature point)

Return or Room Air Humidity (Controlling RH point) (For Enthalpy ECC installed

systems only)

Page 4 –

Economy Cycle Enabled Status (For all ECC installed systems only)

Outside Air Enthalpy or Temperature (specific to the type of ECC installed)

Return Air Enthalpy or Temperature (specific to the type of ECC installed)

Economy Test On/Off (For all ECC installed systems only)

Economy Cycle Low Limit (User Variable) (For all ECC installed systems only)

Subsequent Watch Pages –

All other data points specific to the installation

4.10. DATA LOGGING

All available points should be logged and grouped together on a common program page. This

necessitates that each logged point be assigned and individual label. If system resources are

limited, the following points are to be logged as a minimum -

Supply Fan Fault.



Return Air and or Room Air Temperature/s. (all sensor points and averaged or high

select values as specific to the installation)

Return Air and or Room Air Humidity (For Economy Cycle installations)

Cooling Set-point.

Unit Test Mode function

Heating Set-point if heating is provided

Return Air Enthalpy. (For Enthalpy Economy Cycle installations)

Ambient Air Temperature. (For all Economy Cycle installations)

Ambient Air Relative Humidity. (For Enthalpy Economy Cycle installations)

Ambient Enthalpy. (For Enthalpy Economy Cycle installations)

Economy Damper Actuators. (For all Economy Cycle installations)

All Cooling Stages

Economy Cycle Test Mode function (For all Economy Cycle installations)

Other points specific to a particular configuration such as VESDA Alert, Fire Alarm

shut down, Standby Generator status etc. where these are specified to form an

integral part of a control strategy

Figure 10: Typical Data Logging Layout (for illustration only - not all required points included)

4.11. LEAD / LAG AND DUTY / STANDBY CHANGEOVER

Where lead/lag and duty/standby changeover is required, this should be achieved through a

calendar block and counter function with an automatic reset and user manual advance.



Figure 11: Lead / Lag and Duty / Standby Changeover Logic Diagram

5. APPROVED SOFTWARE AVAILABILITY

Software and HVAC control strategy programming is available from

Innotech Control Systems –

Global Headquarters and Manufacturing

Innotech Control Systems - Brisbane

Office Address:

Brisbane Technology Park, 6 McKechnie Drive

Eight Mile Plains, QLD, 4113, Australia

Postal Address:

PO Box 292

Sunnybank, QLD, 4109, Australia

Phone: +61 7 3841 1388

Fax: +61 7 3841 1644

Office Hours: 7:30 AM - 5:00 PM (EST) Monday - Friday

E-Mail: [email protected]

Web: www.innotech.com.au

mailto:[email protected]

http://www.innotech.com.au/Default.aspx



6. APPLICATION RULES

The control strategy and functions described are applicable to Innotech Maxim and Genesis

series direct digital controllers.

Individual site and HVAC plant specific requirements may necessitate the addition of some

functions such as Supply Air Fan damper control, Toilet Exhaust Fan control or load shedding

of some mechanical cooling capacity during Emergency Power Plant operation etc. However,

the programming methodology, minimum required functions and standard “look and feel”

should not require significant change.

This document applies to all Telstra sites where any HVAC plant is controlled by an Innotech

DDC. This does not apply to small individual modular HVAC plant such as IVTRES or Emerson

TEX plant which is delivered and installed with an integrated pre programmed Innotech DDC.

7. REFERENCES

7.1. 007338

DOCUMENT NUMBER TITLE

C3-1 Network Building Environmental Standards

C3-3 Air Conditioning Services

C3-4 Environmental Controls

C3-5 Economy Cycle

C9-2 Provision of Fire Detection & Alarm Systems and Portable Fire

Extinguishers

E10-1 Multi-Point Aspirated Smoke Detection Systems for Network Sites

7.2. OTHER INTERNAL


Nil

7.3. EXTERNAL


Nil

8. DEFINITIONS

TERM DEFINITION

DDC Direct Digital Controller



TERM DEFINITION

DUTY / STANDBY Two or more HVAC plant controlled in such a manner that only the

duty plant operates and the standby plant is called into operation if

the duty plant fails. The plant designated as duty can be rotated on

a time based schedule

ECC Economy Cycle Cooling. The introduction of up to 100% fresh air

into the HVAC air distribution system when the outside air condition

is suitable.

HVAC Heating, Ventilation and Air Conditioning plant

LEAD /LAG Two or more HVAC plant controlled in such a manner that if heat

load cannot be satisfied by the primary “Lead” plant, then the

cooling strategy will call the additional “Lagging” plant to operate in

unison. The plant designated as leading can be rotated on a time

schedule or fault condition basis.

WATCH PAGE A group of data or controlled point status values viewed via an LCD

front panel of the DDC

9. ATTACHMENTS


Nil



10. DOCUMENT CONTROL SHEET

Contact for Enquiries and Proposed Changes

If you have any questions regarding this document contact:

NAME: MICHAEL WILLIAMS

DESIGNATION: TECHNOLOGY SPECIALIST

PHONE: (03) 8647 5425

EMAIL: [email protected]

If you have a suggestion for improving this document, please contact the person listed above or complete the

online Change Proposal Form at http://www.in.telstra.com.au/ism/007338/feedback.asp

ISSUE

NO.

ISSUE DATE APPROVED NATURE OF AMENDMENT

1.0 May 9, 2011 Chris Baran-Kamp

007338 Technical

Editor

http://www.in.telstra.com.au/ism/007338/feedback.asp

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