White Rodgers 50M56-743 Installation Instructions Manual Download Page 2

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SPECIFICATIONS 

 

ELECTRICAL RATINGS [@ 77°F (25°C)]:

Input Voltage:

 25 VAC 50/60 Hz

Max. Input Current @ 25 VAC:

 0.45 amp

Relay Load Ratings:
Valve Relay:  1.5 amp @ 25 VAC 50/60 Hz 0.6 pf
Ignitor Relay: 6.0 amp @ 120 VAC 50/60 Hz (resistive)
Inducer Relay:      2.2 FLA–3.5 LRA @ 120 VAC
Circulator Relay:  14.5 FLA–25.0 LRA @ 120 VAC

Flame Current Requirements:

Minimum current to insure flame detection: 1 µa DC*
Maximum current for non-detection: 0.1 µa DC*
Maximum allowable leakage resistance: 100 M ohms

*Measured with a DC microammeter in the flame probe lead

TIMING SPECIFICATIONS

(All times are in seconds, unless noted otherwise

Event

Definition

50M56-743

Pre-Purge

The period of time intended to allow for the dissipation of any unburned 
gas or residual products of combustion at the beginning of a furnace 
operating cycle prior to initiating ignition

30

Trial for Ignition 
Period (TFI)

The period of time between initiation of gas flow and the action to 
shut off the gas flow in the event of failure to establish proof of the 
supervised ignition source or the supervised main burner flame.

4

Ignition Activation 
Period (IAP)

The period of time between energizing the main gas valve and 
deactivation of the ignition means prior to the end of TFI

2

Retries

The additional attempts within the same thermostat cycle for ignition 
when the supervised main burner flame is not proven within the first 
trial for ignition period.

2 times

Recycles

The additional attempts within the same thermostat cycle for ignition 
after loss of the supervised ignition source or the supervised main 
burner flame.

3

Valve Sequence 
Period

Valve sequence period equals 4 seconds trial for ignition period x 
(1 initial try + 2 retries) + 12 seconds.

12

Interpurge

The period of time intended to allow for the dissipation of any unburned 
gas or residual products of combustion between the failed trial for 
ignition and the retry period.

60

Post-Purge

The period of time intended to allow for the dissipation of any unburned 
gas or residual products of combustion at the end of a furnace burner 
operating cycle. Post-purge begins at the loss of flame sense.

25

Lockout Time

ANSI standard rated module timing.

275

Heat Delay-To-Fan-On

The period of time between proof of the supervised main burner flame 
and the activation of the blower motor at Heat speed.

30

Heat Delay-To-Fan-Off*

The period of time between the loss of a call for heat and the 
deactivation of the blower motor at Heat speed.

100/150*

Cool Delay-To-Fan-On

The period of time after a thermostat demand for cool before energizing 
the circulator blower motor at Cool speed.

6

Cool Delay-To-Fan-Off*

The period of time between the loss of a call for cool and the 
deactivation of the blower motor at Cool speed.

45

Ignitor Warm-up
(1st 64 attempts)

The length of time allowed for the igniter to heat up prior to the initiation 
of gas flow.

17

Maximum Ignitor 
Warm-up

In the event of a retry, the warm-up time will be increased by one 
second, up to a maximum of 19 seconds, and locked at that duration

19

Auto Reset

After one (1) hour of internal or external lockout, the control will auto-
matically reset itself and go into an auto restart purge for 60 seconds.

60 minutes

Electronic Air Cleaner

Yes

*This time will vary depending on option switch position. The control is factory set at 150 seconds HEAT 

delay-to-fan-off. See OPERATION section for further information

OPERATING TEMPERATURE RANGE:

-40° to 176°F (-40° to 80°C)

HUMIDITY RANGE:

MOUNTING:

Surface mount multipoise

Timing Specs:

 (@ 60 Hz)

 

maximum

Flame Establishing Time: 

0.8 sec

Flame Failure Response Time: 

 2.0 sec

Gases Approved: Natural, Manufactured, Mixed, Liquified 
Petroleum, and LP Gas Air Mixtures are all approved for use.

Summary of Contents for 50M56-743

Page 1: ...instructions to ensure proper operation PRECAUTIONS CAUTION Do not short out terminals on gas valve or primary control Short or incorrect wiring may damage the thermostat Failure to comply with the fo...

Page 2: ...to allow for the dissipation of any unburned gas or residual products of combustion between the failed trial for ignition and the retry period 60 Post Purge The period of time intended to allow for th...

Page 3: ...ire is recommended for all line voltage connections Afterinstallationorreplacement followappliancemanufacturer s recommended installation or service instructions to ensure proper operation Do not shor...

Page 4: ...NSFORMER HOT LINE NEUTRAL LINE FS FLAME SENSOR PROBE TH TR RO OUT RO IN TYPICAL SYSTEM WIRING DIAGRAM Low Voltage 24 VAC Line Voltage 120 VAC LEGEND N C Normally closed switch N O Normally open switch...

Page 5: ...de ignitor NEUTRAL side W G R Y C HLO Pin 1 MV LO Pin 2 TH Pin 3 PSO Pin 4 RO OUT Pin 5 TR Pin 6 HLI Pin 7 GND Pin 8 MV COM Pin 9 PSI Pin 10 RO IN Pin 11 MV HI Pin 12 IND Pin 1 IGN Pin 2 IND N Pin 3 I...

Page 6: ...ges for comfort Auto will adapt the delay to energize MV HI from instantly to up to 12 minutes When the thermostat is satisfied the gas valve is de energized After proof of flame loss the heat delay t...

Page 7: ...fault codes stored can be displayed on the diagnostic LED When the control is in standby mode no call for heat or cool press the FAULT RECALL switch for approximately two seconds or until the diagnost...

Page 8: ...fficient vacuum to engage switch Refer to wiring diagram terminals PSI PSO 4 Open high temperature limit switch Verify continuity through limit switch circuit Refer to wiring diagram terminals HLI HLO...

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