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50A55-438
Integrated Furnace Control
WHITE-RODGERS
INSTALLATION INSTRUCTIONS
Operator: Save these instructions for future use!
FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY BEFORE
INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL
INJURY AND/OR PROPERTY DAMAGE.
DESCRIPTION
The 50A55-438 is an automatic gas interrupted ignition control These controls incorporate system fault analysis for quick gas
that employs a microprocessor to continually monitor, analyze, flow shut-off, coupled
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SPECIFICATIONS ELECTRICAL RATINGS [@ 77°F (25°C)]: TIMING SPECIFICATIONS (All times are in seconds, unless noted otherwise) Input Voltage: 25 VAC, 50/60 Hz Max. Input Current @ 25 VAC: 0.45 amp 50A55-438 Relay Load Ratings: PRE-PURGE 0 Valve Relay: 1.5 amp @ 25 VAC, 50/60 Hz, 0.6 pf TRIAL FOR IGNITION Ignitor Relay: 6.0 amp @120 VAC, 50/60 Hz, (resistive) 4 PERIOD Flame Current Requirements: IGNITION ACTIVATION 1 Minimum current to insure flame detection: 1 μa DC* PERIOD Maximum current for
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INSTALLATION MOUNTING AND WIRING All wiring should be installed according to local and national WARNING electrical codes and ordinances. The control must be secured to an area that will experience a minimum of vibration and remain below the maximum ambient temperature rating of 175°F. The control is approved for mini- mum ambient temperatures of -40°F. When mounting the control, any orientation is acceptable. FIRE HAZARD Choose a location that will not damage, obstruct or place stress • Do not e
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TYPICAL SYSTEM WIRING DIAGRAM HOT NEUTRAL (LINE) (LINE) 120 VAC 24 VAC CLASS II TRANSFORMER TH 24 VAC TR 50A55 COOL HEAT CIRCU- PARK LATOR BLOWER PARK LINE XFMR EAC HUM IND INDUCER IGN IGNITOR IND N HUMIDIFIER IGN N CIR N LINE N XFMR N HUM N ELECTRONIC EAC N AIR CLEANER Y Y COMPRESSOR W W CONTACTOR G G R R THERMOSTAT C PRESSURE SWITCH (N. O.) PS HLI FLAME HLO HIGH LIMIT AUX. HIGH SENSOR FP (N. C.) LIMIT (N. C.) PROBE GND GAS VALVE MV MV TR TH LEGEND Low Voltage (24 VAC) Line Voltage (120 VAC) N.
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TYPICAL SYSTEM WIRING TABLE 50A55 TERMINAL SYSTEM COMPONENT TERMINAL TYPE CONNECTION W low voltage thermostat W terminal (or equivalent) G Terminal low voltage thermostat G terminal (or equivalent) R block with low voltage thermostat R terminal (or equivalent) Y captive low voltage thermostat Y terminal (or equivalent) screws (2nd wire from Y terminal goes to 24 VAC HOT side of compressor contactor coil) C 24 VAC COMMON side of compressor contactor coil MV (2 terminals) gas
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OPERATION system for 5 seconds. When the purge is complete, the inducer OPTION SWITCHES blower and humidifier are de-energized. After the delay-to-fan- The option switches on the 50A55-438 control are used to off period ends, the circulator fan and electronic air cleaner are determine the length of the cool delay-to-fan-off and heat delay- de-energized. If flame is not detected, both valves are de- to-fan-off periods. The following tables show the time periods energized, the ignitor is turned of
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DIAGNOSTIC FEATURES SYSTEM LOCKOUT AND The 50A55 control continuously monitors its own operation and DIAGNOSTIC FEATURES the operation of the system. The LED light on the control will flash slowly (one flash per second) if there are no failures and no call for heat. If there is a call for heat, the LED will flash quickly SYSTEM LOCKOUT FEATURES (one flash per half-second). If a failure occurs, the LED will When system lockout occurs, the gas valve is de-energized, the indicate a failure code as
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MOUNTING HOLE TEMPLATE MOUNTING HOLE TEMPLATE FOR MOUNTING HOLE LOCATIONS 4.172 – .007 (2 plcs.) 6.402 – .010 (2 plcs.) Refer to page 3 of the installation instructions for proper installation.
