Every Madison float switch has a float containing a magnet and a dry reed switch encapsulated within astem. The float travel in the liquid magnetically actuates the reed switch, providing an “on” or “off” function.
NORMALLY CLOSEDNORMALLY OPEN
Float Switch Technology
Operation (NO/NC)
Every Madison float switch contains a dry reed switch encapsulated within a stem. Reed switches are highly reliableand able to deliver more than 5 million switching cycles when operated at their rated electrical load. To ensure manyyears of operation, it is important to consider the electrical load conditions to which the switch will be subjected.
All reed switches are rated for resistive loads or steady state current. Devices such as motors, solenoids, coils, strobesor tungsten lights are capable of producing a capacitive or inductive electrical load. When power is applied or removed,these devices can produce a current spike that is four to ten times the steady state current. The resulting exposure tohigh current can burn the reed switch contacts or fuse the reeds together, causing a shortened switch life or failure.
We recommend that a circuit be used to protect a reed switch from current overload caused by a capacitive orinductive device. The commonly-used circuits shown below will allow the switch to function while preventing highcurrent from damaging the reed switch contacts.
—+
Ind. Load
DC Contact Protection/Load Drain
1N4004
Note: For AC loads, the diode can be replaced with a varistor.
—+
Ind. Load
100‰ .1 F 600V
Reed Protection
V
R
Is
R = Current limiting resistor("R" should be selected to give "Is" less than the rated carrying current.)
Lamp Loads
Switch operation is determined while theswitch is in the dry position with theinstallation fitting up.
Normally Closed: Switch will open on therise of liquid and close on the fall of liquid.
Normally Open: Switch will close on therise of liquid and open on the fall of liquid.
Madison switches are supplied in thenormally closed (NC) position, unlessotherwise specified.
Reed Contact Protection
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
The first consideration is the type of liquid, temperature and pressure to which the switch will be subjected. Madisonmanufactures liquid level switches in various styles, in a variety of materials, to cover a broad range of conditions.Following are some basic recommendations for selecting the proper liquid level switch material for your application.
Madison Company also manufactures selected switch models in a combination of materials that are available fromstock or in a custom, build-to-order configuration.
Once a suitable material has been selected, the type of switch and configuration of actuation points, fittings and wireterminations are the next considerations. Madison Company stocks a full line of standard products that can meet therequirements of many applications. For specific designs, Madison can custom build, to order, switches with an infinitenumber of variations and options.
Material
316 StainlessSteel
Polypropylene
Brass & Buna-NPBT & Buna-N
Kynar
Application
For high-temperature (to 200˚C), high-pressure (to 300 PSIG) andcorrosive conditions. Commonly used in food processing, medical, heating and cooling equipment.
For acidic conditions, such as found in electroplating and metal cleaning.Another choice for lower-temperature (to 105˚C) food processingapplications (Madison Company uses only polypropylene that is FDA-approved for food contact). Also a good choice for general-purposeapplications in commercial or consumer appliances and equipment.
The selection for petroleum-based liquids, such as lubricating oils,gasoline and diesel fuels. Widely used in storage tanks of vehicles,generators, transmissions and hydraulic systems. Other uses are inlubrication, recovery, refining and fuel processing equipment.Please note: PBT is not suitable for use in water above 65°C.
Chemical- and solvent-resistant properties make this material a problem solver for many applications. Its high purity nature is ideal for food handling and sensitive laboratory or test equipment.
Material Selection Guide
Environmental Considerations
Intensive agitation of liquid, boiling fluids andsurging due to large inflows of liquid can all causeturbulence and erratic float switch operation. Thisproblem can be eliminated by the use of sloshshields with adequately-sized fluid and vent holes,as illustrated here. Available for vertical, horizontal(side-mounted) and multi-level switches with full-size or miniature floats, these slosh shields can besupplied in stainless steel, brass, polypropylene,PBT or Kynar.
Turbulence
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Material Type
316 Stainless Steel
Brass & Buna-N
PBT & Buna-N
Kynar
Polypropylene
PBT (PolybutyleneTerephthalate)
N/A - Not AvailableSlosh Shields for turbulence protection available on most switches.Other material combinations, submersibles and specialty switches are available.
TypicalApplications
High temperatureHigh pressure
Corrosive conditions
Lubricating oilsHydraulic fluids
Gasoline and diesel fuels
All plasticLubricating oils Hydraulic fluids
Gasoline and diesel fuels
Chemical resistantHigh purity applications
General purposeFDA approved for food use
Acidic conditions
All plasticLubricating oilsHydraulic fluids
Gasoline and diesel fuels
Mounting:Build to Order
Side Mount
Full-Size Float
Vertical Mount
SingleThread
M5010M5970
M4010
N/A
N/A
M8750M8790M8725
M7750M7790M7725
DualThread
M5900M5910M5920
N/A
N/A
M9700
M8700M8740
M7700M7740
StandardSwitch
M5600M5917
(others)
M4300(others)
M7800(others)
M9800
M8800(others)
N/A
Power ReedSwitch
M5600PR(others)
N/A
N/A
N/A
M8800PR(others)
N/A
MiniatureFloat
M5000(others)
M4500(others)
M7000
M9000
M8000(others)
N/A
SubminiatureSwitch
N/A
N/A
N/A
N/A
M3326
N/A
Multi-LevelSwitch
M5602M5002
(w/ options)
M4302M4402
(w/ options)
N/A
M9802M9090
(w/ options)
M8802M8080
(w/ options)
N/A
IN STOCK
General Product Guide
Selected Switches
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com © Copyright Madison Company – 2/03
Nominal VA
360
100
60
30
25
15
Amperes(resistive)at 220 VAC
1.50
0.40
0.40
0.14
–
0.07
Amperes(resistive)at 110 VAC
3.00
1.00
0.50
0.28
0.28
0.15
Amperes(resistive)at 120 VDC
0.75
0.40
0.20
0.07
–
0.03
Amperes(resistive)at 24 VDC
3.00
1.00
0.50
0.28
0.28
0.14
Above ratings are for resistive loads only.Maximum voltage ratings: SPST Switches – 220 VAC
SPDT Switches – 120 VAC
Electrical Data
UL Current & Voltage Ratings
Madison has extensive experience in the design and production of tank level controls. Level switches with two or more floats are often used as part of a control system forpumps and other filling devices. For single-phase devices, such as solenoids and pumps with fractional horsepower motors, a single relay circuit may be incorporated in an enclosure for either filling or draining operations. For larger pumps, where three-phase operation is required, the same relay circuit can be used to control the three-phase contactor in the motor control circuit. Consult Madison's fluid control engineers for assistance with these applications. Typical circuits for this type of control are illustrated here.
TopSwitch
BottomSwitch
Relay
Relay
Single Phase Pump Motoror 3-Phase Contactor Coil
or Solenoid Valve
BottomSwitch
TopSwitch
Relay
Relay
Single Phase Pump Motoror 3-Phase Contactor Coil
or Solenoid Valve
For Pump-Up Applications
For Pump-Down Applications
Tank Level Control
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Wire Color Guide
Wire Colors forStandard Switches
Wire Colors for Full-Size Multi-Level Switches with SPDT Switches
Note: Maximum of four levels with SPDT switches
WireColor
White
Black
Yellow
Brown
Red
Switch Materialor Model No.
Polypropylene
Stainless Steel,Brass/Buna-N, PBT
Kynar
M3326
M3326-NO
Number ofSwitches
1
2
3
4
Color Code(Top to Bottom)
C - Black, NO - Green, NC - Yellow
C - Blue, NO - White, NC - RedC - Black, NO - Green, NC - YellowC - Blue, NO - White, NC - RedC - Brown, NO - Orange, NC - VioletC - Black, NO - Green, NC - Yellow
C - Blue, NO - White, NC - RedC - Brown, NO - Orange, NC - VioletC - Grey, NO - Red/White, NC Yellow/WhiteC - Black, NO - Green, NC - Yellow
Electrical Data
Note:Custom colors are available at customer request.
Wire Colors forFull-Size and Miniature
Multi-Level Switcheswith SPST Switches
Number of Switches
2
3
4
5
6
Color Code (Top to Bottom)
RedBlack
RedWhiteBlack
RedWhiteBlueBlack
RedWhiteBlue
GreenBlack
RedWhiteBlue
GreenYellowBlack
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Pipe Plug Flange Male Thread Bulkhead
Madison multi-level switches areavailable with bulkhead, male thread,male pipe plug or flange mounting.These switches may be mounted withthe stem at up to a 30° angle from thevertical position.
Obstructions in tanks and difficultmountings often require bending the tube to allow proper installation.Madison's engineering staff can design switches with offset stems to solve many types of installationproblems. All metal stems areavailable with offset configurations.
Multi-Level Switches
Typical Installation Fittings
Offset Stems
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Many Madison switches can befurnished in adjustable form,permitting installation personnelto set any desired level of switchactuation. A male pipe plug withintegral compression fitting isinstalled in the tank. The tube containing the reed switch can then be adjusted to actuate at anydesired level. All metal multi-levelswitches are available with the adjustable feature.
Mounting Plug
Compression Fittingfor Adjusting Length
1/2" NPTConduit Connector
Multi-Level Switches
Adjustable Liquid Level Switches
Madison Company uses special floats, stems, fittings and construction techniques to produce level switcheswhich will operate properly under conditions of severely high pressure. Two high pressure ranges are available:HP (750 PSIG maximum) and VHP (1500 PSIG maximum).
The M5602 switch with 2" NPT pipe plug mounting is available for use under high-pressure conditions.
High-Pressure Applications
Switch Set Up Criteria
Special OptionsPlease consult factory concerning available options such as the following:
• TERMINATIONS • TEMPERATURE SENSORS • OTHER FITTINGS • ADJUSTABLE FITTINGS
• OFFSET SWITCHES • JUNCTION BOXES • EXTRA CABLE LENGTHS • CABLE • FLOATS
For M5002, M5042, M8080, M8002, M8042,M4402, M4502, M9090
L (Total) = L4 + 1" (25.4mm) Min.
Distance from mounting fitting to first switch = 5/8" (15.8mm) Min.
Minimum distance between floats:1-1/2" (38.1mm)
Minimum LH = 1-1/2" (38.1mm)
* Note: 3 levels maximum on models M8080 and M9090.
For M8802, M9802
L (Total) = L5 + 2" (50.8mm) Min.
Distance from mounting fitting to first switch = 1-3/4" (44.4mm) Min.
Minimum distance between floats: 3" (76.2mm)
For M5602, M5402, M8602, M8402, M4602, M4302
L (Total) = L5 + 1-1/2" (38.1mm) Min.
Distance from mounting fitting to first switch = 1-1/4" (31.7mm) Min.
Minimum distance between floats: 2-1/2” (63.5mm)
Minimum LH = 2-1/2" (63.5mm)
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
1. How can I connect my float level switch to a pump or valve while protecting it from thehigh current that these devices use?
1a. How can I control my pump to maintain a range of fluid in my application?
2. How can I tell if my switch is set for normally open (NO) or normally closed (NC)operation? How can I change from NO to NC (or vice versa)?
3. How can I determine the current and voltage rating for my switch?
4. Is there a way to sense between two liquids?
5. How do I know what the Specific Gravity of my switch is?
6. Which switch material is best suited for my liquid level application?
7. Can I order directly through Madison, or should I go through a distributor?
8. How can I ensure that my switch's performance will not be affected by turbulence?
9. Can I customize a standard switch?
10. Which Madison switches are explosion-proof?
11. Are liquid level switches affected by semi-solid particles or magnetic particles in the liquid?
12. What industry ratings do Madison's switches have?
13. What types of testing do Madison switches undergo?
14. What type of warranty does Madison offer on its sensors? What is the return policy?
15. Does Madison offer special packaging and/or labeling?
16. How does Madison keep such a large variety of sensors in stock?
17. What kind of lead time can I expect once I order my switch? Is there a difference whenordering standard or custom switches?
18. Can I order a Madison switch with more than one level?
Level Sensors
Frequently-Asked Questions
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Level Sensors
Frequently-Asked Questions
1. How can I connect my float level switch to a pump or valve while protecting it from the highcurrent that these devices use?
In most applications, a relay is required to isolate the float switch from the device. The float switchwill be connected in series with the relay input coil that typically draws less than 500milliAmps.When the switch is closed, the relay coil is activated and closes the output contacts. These contactsturn on or off the high current required by the device.
1a. How can I control my pump to maintain a range of fluid in my application?
Madison offers several solutions to control fluid levels in custom applications. The most common isby using a Double Pole Double Throw (DPDT) relay combined with a custom two-level float switchor two independent Normally Open float switches placed at the levels to turn the pump on and off.
The diagrams shown on the fourth page of this Reference section illustrate typical circuits for these"pump-up" or "pump-down" applications.
Madison also stocks an R2 pump controller that can be used with float switches or conductivityprobes. Madison stocks relays and controllers to activate pumps, solenoid valves, motors andalarms. Our fluid control engineers are on-hand to assist you with these applications.
2. How can I tell if my switch is set for Normally Open (NO) or Normally Closed (NC) operation?How can I change from NO to NC (or vice versa)?
Each style switch is equipped with a means to identify which type of operation to which the switch is set.
Vertical: NO/NC operation is indicated by the position of the witness mark (stainless steel models)or magnets (plastic models). NO is indicated by circle up (stainless steel) or magnets down plastic); NC is indicated by circle down (stainless steel) or magnets up (plastic).
Horizontal: NO/NC operation is indicated by the direction of the arrow on the float. NO is indicatedby arrow up; NC is indicated by arrow down. An ohmmeter or continuity meter can be used toverify the switch setting and operation. Simply connect the meter to the leads and, with the floathanging down away from the fitting, measure the switch. If the meter reads a short, then the switchis normally closed and will open on rise.
All switches are shipped in the Normally Closed (NC) position, unless otherwise specified. Tochange the contact operation, simply remove the retaining ring and float and reverse the float onthe stem. The only exception to this is the subminiature switch (M3326/M3326-NO), for whichoperation must be specified when ordered, since the float is not reversible on this switch.
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Level Sensors
Frequently-Asked Questions
3. How can I determine the current and voltage rating for my switch?
We recommend that switches stay below these ratings for non-resistive loads.
Current and Voltage ratings are for resistive loads only. For inductive loads, maximum life will beachieved if appropriate arc suppression is used.Maximum voltage ratings: SPST Switches — 220 VAC
SPDT Switches — 120 VAC
Each switch has a power rating in watts. These power ratings are for resistive loads that are atsteady state and are calculated as Power (Watts) = Voltage (AC/DC) * Current (Amps-resistiveload). Most devices have other things to consider, such as current or voltage spikes caused whenpowering up or shutting down. Common devices such as pumps, coils and light bulbs can createthese types of spikes. For these more complex cases, one must remember to stay within themaximum current and voltage ratings of the switch regardless of the power rating.
For example, our 30-watt standard switches have a maximum switching current of 1 Amp and acarrying current of 2.5 Amps. If the switch is connected to a 12 V circuit that spikes to 2 Amps andruns at steady state at 1 Amp, the power spike exceeds the switch rating although the steady staterunning power is 12 Watts. Due to the heat and type of power dissipated during the spike, thecontact may be damaged or even welded together, causing switch failure.
Custom designs have other elements to consider and even alternative ground paths that mayaffect the power delivered to a switch. It is important to consult your engineering departmentbefore assuming the system's power requirements. Contact the factory for additional assistance.
Nominal VA
360
100
60
30
25
15
Amperes(resistive)at 220 VAC
1.50
0.40
0.40
0.14
–
0.07
Amperes(resistive)at 110 VAC
3.00
1.00
0.50
0.28
0.28
0.15
Amperes(resistive)at 120 VDC
0.75
0.40
0.20
0.07
–
0.03
Amperes(resistive)at 24 VDC
3.00
1.00
0.50
0.28
0.28
0.14
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
UL Current and Voltage Ratings
Level Sensors
4. Is there a way to sense between two liquids?
Madison can furnish an Interface Float that, given two mediums, is designed to sink in one mediumand float in the other. A typical application would be one where oil and water accumulate in onetank, and sensing of only a fall in water level is required (oil level is not an issue). Since a standardfloat of any material will float in any liquid with a specific gravity higher than the specific gravity ofthe float, Madison would “weight” the float to a specific gravity of 0.95. Since the specific gravity ofthe oil is 0.8-0.9 and that of the water is 1.0, the float will sink in the oil and float in the water. Bothfull-size Buna-N and polypropylene floats can be modified in this manner.
5. How do I make sure the switch I choose has the correct specific gravity?
One of the main considerations when choosing a switch is the specific gravity of the float. To makesure the float will function properly in the application, the specific gravity of the fluid must be greaterthan the float's specific gravity at the maximum temperature range of the application. For reference,below are specific gravities of some of our floats.See our Standard Floats page for details.
Full size floats:Stainless steel — 0.55 SG, except M5600-PR float is 0.70 SGPolypropylene — 0.60 SGBuna-N — 0.45 SGKynar — 0.75 SG
Miniature floats:Stainless steel — 0.60 SGPolypropylene — 0.60 SG, except M3326 is 0.80 SGBuna-N — 0.45 SGKynar — 0.80 SG.
Side-mounted floats:M5900 series (stainless steel) — 0.60 SGM5970 — 0.70 SGM5010 — 0.60 SGM4010 — 0.45 SGPolypropylene — 0.60 SGPBT — 0.75 SGKynar — 0.75 SG
Frequently-Asked Questions
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Level Sensors
Frequently-Asked Questions
6. Which switch material is best suited for my liquid level application?
316 Stainless Steel: For high-temperature (to 200°C), high-pressure (to 300 PSIG) and corrosiveconditions. Commonly used in food processing, medical, heating and cooling equipment.
Polypropylene: For acidic conditions, such as found in electroplating and metal cleaning. Anotherchoice for lower-temperature (to 105°C) food processing applications (Madison Company uses onlypolypropylene that is FDA-approved for food contact). Also a good choice for general-purposeapplications in commercial or consumer appliances and equipment.
Brass & Buna-N, PBT & Buna-N: The selection for petroleum-based liquids, such as lubricatingoils, gasoline and diesel fuels. Widely used in storage tanks of vehicles, generators, transmissionsand hydraulic systems. Other uses are in lubrication, recovery, refining and fuel processingequipment. PBT is not suitable for use in water at temperatures above 65°C.
Kynar: Chemical- and solvent-resistant properties make this material a problem solver for manyapplications. Its high-purity nature is ideal for food handling and sensitive laboratory or testequipment.
7. Can I order directly from Madison, or should I go through a distributor?
Madison products can be ordered direct from the factory. Minimum order is $300.We accept payment by credit card (Visa, MasterCard and American Express) or COD. Please contact Madison to set up an account on open terms.
We also have a network of distributors located in various regions across the U.S. and Europe.Please visit http://www.madisonco.com/reference/reps.htm.
8. How can I ensure that my switch's performance will not be affected by turbulence?
Turbulence, which can be caused by a vibrating tank, intensive mixer agitation or surging of liquidduring tank filling, can result in premature failure of both the switch and the relay, due to chattering.A very low-cost, reliable solution to this problem is the use of a slosh shield. This device is equippedwith fluid and vent holes and surrounds the switch float to prevent erratic switch operation.
Madison stocks a complete selection of slosh shields for vertical and horizontal switches in stainlesssteel, polypropylene, PBT, brass or Kynar.
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Level Sensors
Frequently-Asked Questions
9. Can I customize a standard switch?
Madison Company offers a full range of value-added options, including terminations andconnectors; extra-long or -short lead lengths; special cable or wire, other than standard; shrinktubing for wire protection; and special sealing materials, such as Viton or Buna-N gaskets and O-rings. We can also meet special requirements with our temperature switches, slosh shields andweather-proof or explosion-proof junction boxes.
10. Which Madison switches are explosion-proof?
Our vertical M5600 series and our horizontal M5900 series are rated explosion-proof by UL andCSA for use in Hazardous Locations, Class I, Groups A, B, C, D; Class II, Groups E, F, G; Class I.These switches are also approved by DEMKO for use in potentially explosive atmospheresEEx d IIC T2 and carry the Ex mark.
11. Are liquid level switches affected by semi-solid particles or magnetic particles in the liquid?
Yes, standard float switches may be affected by these conditions because such particles cancause a float to stick or to not operate at all. Instead, we recommend using a conductivity switch,such as our multi-level model M3784 or single level model M3850. Because our conductivityswitches have no moving parts, operation of these switches is not interrupted. Furthermore, theM3827 side-mounted switch is engineered such that the magnetically actuated reed switch will notcome in contact with the fluid being monitored. The float is attached to an extended pivot arm that,when moved, triggers the switch function. This switch is ideal for use in heavy-bodied liquids or influids containing metal particles that would otherwise be attracted to a conventional style float.
12. What industry ratings do Madison's switches have?
We have a continuing program to upgrade our list of UL and CSA approvals. Madison Company'sliquid level switches have general-purpose approval as recognized components granted by ULunder file number E54633 and CSA file number LR56150.
Madison switches are also NSF-certified for food applications.
In addition, we are self-certified for CE under the following directives:
EN60730-1 — Automatic Electric Controls for Household and Similar Use - Part 1: GeneralRequirements (1995)
EN60730-2 — Automatic Electric Controls for Household and Similar Use - Part 2: ParticularRequirements - Section 2-15: Automatic Electrical Water Level Sensing of the Float or Electrode-Sensor Type used in Boiler Applications (1996)
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
Level Sensors
Frequently-Asked Questions
Low Voltage Directive (72/73/EEC)
Our M5600 and M5900 switches are certified explosion proof by DEMKONo. 99E.126064X EEx d IIC T2: Protected for use in potentially explosive atmospheres.Click here for details on Madison's approvals.
13. What types of testing do Madison switches undergo?
Madison Company periodically life tests the reed switches used in its liquid level switches. This isdone to ensure that the reed switches, as obtained from our vendors, have not had a shift inoperating characteristics. The reed switches are tested, rather than the complete assembly,because they are the principal electrical component of the liquid level switch.
The testing is performed by cycling the switch, using a standard coil, one million times. The load onthe switch is an incandescent light bulb rated for the maximum wattage of the reed switch (i.e., a60-watt bulb is used to test a reed switch rated at 60 watts maximum).
A resistive load (light bulb) is used because it provides a uniform standard against whichcomparisons can be made. Inductive loads vary greatly from device to device, making comparativeanalysis very difficult.
The degree of deterioration of a reed switch after life cycle testing is measured by determining thechanges in contact resistance, pull-in force and drop-out force as compared to those samemeasurements made before testing commenced.
Madison Company has the capability of doing life-cycle testing of reed switches using specificelectrical loads, such as relays or solenoids supplied by our customers. Please contact the factoryfor more information.
14. What type of warranty does Madison offer on its sensors? What is the return policy?
Our sensors are warranted for one year from date of manufacture. We only accept returns that areauthorized by the factory. Please contact the Sales Department for a Return Authorization Number.
15. Does Madison offer special packaging and/or labeling?
Yes, we offer a variety of custom packaging — bar coding, special unit packs, etc. Please contactthe factory for more information.
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
16. How does Madison keep such a large variety of sensors in stock?
In order to better serve our customers, we continually review our Lean Manufacturing techniquesand Kanban systems to meet demands. These systems eliminate both overstocks and stockoutsand allow us to maintain the proper level of inventory for both standard switches and custom fittings.
17. What kind of lead time can I expect once I order my switch? Is there a difference when orderingstandard or custom switches?
Standard switches have a lead time of one to two weeks. Custom switches have a three-weeklead time.
18. Can I order a Madison switch with more than one level?
Yes, Madison offers multi-level switches in many configurations. Our full-size multi-level switchescan be set for up to six levels, and our miniature switches can be set for up to four levels. They canbe mounted within any vessel, utilizing male pipe threads, pipe plugs, flanges or bulkhead fittings.The length of each switch, as well as the location of the floats, can be established by the designer.For those users who want to design and install their own systems, multi-level switch kits areavailable in three different materials. Click here for the multi-level switch specification sheet for easyconfiguration and ordering.
Level Sensors
Frequently-Asked Questions
Madison Company • (203) 488-4477 • Fax (203) 481-5036 • E-mail: [email protected] • www.madisonco.com
© Copyright Madison Company – 2/03
C - CE
Approval Reference
A - Underwriter’s Laboratories
Underwriter’s Laboratories is one of the world’s premier safety testing andcertification sources. Many applications require UL approval for insuranceand/or other compliance purposes. There are several areas of interest,
but the most applicable is UL 508, the Standard for Industrial Control Equipment. For moreinformation on UL, check their Web site at www.ul.com.
Madison Company offers many sensors with UL approval. Those product approvals are to aspecific design. Some modifications to an approved design may cause the approval to beinvalid. Should that be a critical issue for you, contact us to determine what course of actionwould be best.
B - Canadian Standards Association
Canadian Standards Association (CSA) tests products for compliance to nationaland international standards and issues certification marks for qualified products.Certification marks tell potential users that a product has been evaluated by aformal process involving examination, testing and followup inspection, and that it
complies with applicable standards for safety and performance. CSA is recognizedthroughout Canada as the premier certification organization for electrical products. Formore information on CSA, visit their Web site at www.csa-international.org.
As with UL approval, CSA certification is design-specific. Therefore, modifications to acertified design may cause the certification to be invalid. Please confer with MadisonCompany if this certification is crucial for your application.
The 15 member nations of the European Union (EU) have created a set ofproduct-specific regulations with which those companies doing business in thosenations must comply. The EU’s “New Approach Directives” constitute its unified set
of health and safety regulations, symbolized by the CE mark. The mark is required for abroad range of products, including machinery, medical devices and electrical/electronicproducts. Madison Company self-certifies all of its level switches to CE specificationsEN60730-1 and EN60730-2, and Low Voltage Directive (72/73/EEC).
Continued on next page
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Approval Reference
E - Explosion-Proof
Danish DEMKO A/S has been testing and certifying electrical products for morethan 65 years. The DEMKO mark is recognized and accepted throughout theworld. DEMKO participates in all relevant national and international agreements,and testing at DEMKO provides the basis for national certification marks
throughout the world – Global Certification. One such agreement, which includes theEuropean Union countries only, pertains to explosion-proof products. The DEMKO Ex mark(Epsilon X) can only be used for products that have been approved by a recognized testingstation to carry it. Madison Company’s M5900 series and M5600 are approved for use inpotentially explosive atmospheres EEx d IIC T2 and therefore carry the Ex mark. TheM5600 is also rated explosion-proof to CSA standard LR26414, For Hazardous LocationsClass I, Groups A, B, C, D; Class II Groups E, F, G; Class III. For more information onDEMKO, visit their Web site at www.demko.dk.
Continued on next page
D - NSF International
NSF International sets standards for products and systems related to publichealth, safety and the environment with focus on the essential elements of water,food environment and air. The NSF Certification programs are accepted and
frequently mandated by public health regulators throughout the United States, as well asinternationally. Madison Company offers over 30 NSF-approved sensors which meet NSFStandard C-2 – Food Equipment and Related Products, Components and Materials. Formore information on NSF, visit their Web site at www.nsf.org.
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International Protection Codes (IP)An IP number is used to specify the environmental protection of enclosures aroundelectronic equipment.
First Number0 - No protection (sometimes X)1 - Protected against solid objects up to 50mm2
2 - Protected against solid objects up to 12mm2
3 - Protected against solid objects up to 2.5mm2
4 - Protected against solid objects up to 1mm2
5 - Protected against dust, limited ingress(no harmful deposit)
6 - Totally protected against dust
Second Number0 - No protection (sometimes X)1 - Protected against vertically falling drops of water (i.e. condensation)2 - Protected against direct sprays of water up to 15˚ from vertical3 - Protected against direct sprays of water up to 60˚ from vertical4 - Protected against water sprayed from all directions - limited ingress permitted5 - Protected against low-pressure jets of water from all directions - limited ingress
permitted6 - Protected against low-pressure jets of water, limited ingress permitted (i.e. ship deck)7 - Protected against the effect of immersion between 15cm and 1m 8 - Protected against long periods of immersion under pressure
Approval Reference
NEMA 1 Indoor Use Protects against accidental contact by personneland falling dirt
NEMA 2 Indoor Use Protects against falling dirt, liquid and light splash
NEMA 3 Outdoor Use Protects against rain, sleet, snow, dirt and dust
NEMA 3A Outdoor Use Protects against rain, sleet, snow, dirt and ice buildup
NEMA 4 In- or Outdoor Protects against dirt, dust, hosedown andheavy splash
NEMA 4X In- or Outdoor Protects against dirt, dust, hosedown and prolonged submersion
NEMA 6 In- or Outdoor Protects against dirt, dust, hosedown andoccasional submersion
NEMA 6P In- or Outdoor Protects against dirt, dust, hosedown and prolonged submersion
NEMA 7 Indoor Use For use in areas of explosive gases or vaporsor combustible dust
NEMA 9 Indoor Use For use in areas of atmospheres containingcombustible dust
NEMA 12 Indoor Use Protects against dirt, dust, light splash and oilor coolant seepage
NEMA 13 Indoor Use Protects against dirt, dust, light splash and oil orcoolant spray
National Electrical Manufacturers Association (NEMA) Standards Publication No. 250guidelines are as follows:
NEMA
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National Standards
Thermocouple Wire Color CodesColor codes have been adopted by various national and international standard agencies for identification of thermocouplewire and thermocouple products. In the United States, thermocouple-grade wire normally has a brown overall jacket. ForTypes B, R and S, the color codes relate to the compensating cable normally used.
Type
E
J
K
N
B
R
S
T
United StatesANSI96.1
Purple+ Purple- Red
Black + White- Red
Yellow + Yellow- Red
Orange+ Orange- Red
Grey+ Grey- Red
Green+ Black- Red
Green+ Black- Red
Blue+ Blue- Red
United KingdomBS
1843
Brown+ Brown- Blue
Black + Yellow- Blue
Red + Brown- Blue
—
—
Green+ White- Blue
Green+ White- Blue
Blue+ White- Blue
West GermanyDIN
43714
Black+ Red- Black
Blue + Red- Blue
Green + Red- Green
—
Grey+ Red- Grey
—
White+ Red- White
Brown+ Red- Brown
JapanJIS
C1610-1981
Purple+ Red- White
Yellow + Red- White
Blue + Red- White
—
Grey+ Red- White
Black+ Red- White
Black+ Red- White
Brown+ Red- White
FranceNF
C42-323
—
Black + Yellow- Black
Yellow + Yellow- Purple
—
—
—
Green+ Yellow- Green
Blue+ Yellow- Blue
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Comparison of Temperature Transducers
Thermocouple Reference
Time Constants
The time constant of any sensor isdefined as the time required for thatsensor to respond to 63.2% of its totaloutput signal when subjected to a stepchange. The step change can be eitheran increase or decrease in theparameter being measured. Fiveconstants are required for a sensor toreach 99% of its total change. Thegraph to the right illustrates thisrelationship.
Type
Advantages
Disadvantages
Thermocouple
Self-powered
Simple, rugged
Lower cost
Wide temperature range
Nonlinear
Low voltage
Least stable
Least sensitive
Reference required
RTD
Most stable
Most accurate
Better linearity
Expensive
Current source required
Small resistance change
Low absolute resistance
Self-heating
Thermistor
High output
Fast
Nonlinear
Limited temperature range
Fragile
Current source required
Self-heating
0 1 2 3 4 5
63
100
Per
cen
t o
f C
han
ge
Time Constant
99%
Type
Material
Temperature Range
J
Iron (+)vs.
Constantan (-)
0˚C to 760˚C
K
Nickel (10%) Chromium (+)vs.
Nickel (5%) AluminumSilicon (-)
0˚C to 1370˚C
T
Copper (+)vs.
Constantan (-)
-160˚C to 400˚C
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Time Constants and Radiation Error
Time Constant of Exposed Thermocouples
Time Constant as a Function ofWire Size for Exposed Wire
Thermocouples in Air T=200°F
Radiation Error of Exposed Thermocouples
Radiation Error as a Function ofWire Sizes for Thermocouples inAir at 2000°F, at 1 Atmosphere
and Mach 0.3
0
0
0.5
1.0
1.5
2.0
.004 .008 .012 .016 .020 .024
Tim
e C
on
stan
t, se
c.
Wire Diameter, in.
MICRO-MINIATURE THERMOCOUPLE
40 GAUGE
36 GAUGE
30 GAUGE
28 GAUGE
26 GAUGE
24 GAUGE
22 GAUGE
400
300
200
100
00 .02 .04 .06 .08 .10 .12
Rad
iati
on
Err
or,
˚F
Wire Diameter, in.
40 GAUGE
36 GAUGE32 GAUGE30 GAUGE
26 GAUGE
24 GAUGE
20 GAUGE
16 GAUGE
10 GAUGE
8 GAUGE
MICRO-MINIATURE THERMOCOUPLE
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