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50A55-143
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 50A55-143 is an automatic gas interrupted ignition
control that employs a microprocessor to continually
monitor, analyze, and control the proper operation of the
gas burner, inducer, and fan.
Signals interpr
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SPECIFICATIONS ELECTRICAL RATINGS [@ 77°F (25°C)]: TIMING SPECIFICATIONS Input Voltage: 25 VAC 50/60 Hz (All times are in seconds, unless noted otherwise) Max. Input Current @ 25 VAC: 0.45 amp 50A55-143 Relay Load Ratings: Valve Relay: 1.5 amp @ 25 VAC 50/60 Hz 0.6 pf PRE-PURGE 30 Ignitor Relay: 6.0 amp @ 120 VAC 50/60 Hz (resistive) INITIAL IGNITOR WARM-UP (1st 64 17 Inducer Relay: 2.2 FLA–3.5 LRA @ 120 VAC attempts) Circulator Relay: 14.5 FLA–25.0 LRA @ 120 VAC Flame Current Requirements: MIN
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INSTALLATION MOUNTING AND WIRING NOTE All wiring should be installed according to local and WARNING ! national electrical codes and ordinances. Do not use on circuits exceeding specified The control must be secured to an area that will experi- voltage. Higher voltage will damage control ence a minimum of vibration and remain below the maxi- and could cause shock or fire hazard. mum ambient temperature rating of 175°F. The control is approved for minimum ambient temperatures of -40°F. CAUTION ! W
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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 CIRCULATOR PARK BLOWER PARK LINE XFMR EAC INDUCER HUM IND IGN IGNITOR HUMIDIFIER CIR N LINE N XFMR N HUM N ELECTRONIC EAC N AIR CLEANER Y Y COMPRESSOR W W CONTACTOR 50A55-143 G G IN OTHER FURNACES R R TWINNING THERMOSTAT C APPLICATIONS ONLY TWIN* TWIN* PRESSURE SWITCH (N. O.) PS HLI HLO FLAME HIGH LIMIT AUX. HIGH FP SENSOR (N. C.) LIMIT (N. C.) RO1 PROBE ROLLOUT GND (N. C.) GA
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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) TWIN one wire twinning terminal C 24 VAC COMMON side of compressor cont
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OPERATION At the end of the ignitor warm-up time, both valves in the OPTION SWITCHES 36E manifold gas valve are opened. Flame must be The option switches on the 50A55-143 control are used to detected within 4 seconds. determine the length of the heat delay-to-fan-off periods. If flame is detected, the delay-to-fan-on period begins. The following table shows the time periods that will result After the delay-to-fan-on period ends, the optional elec- from the various switch positions. tronic air c
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COOL MODE SYSTEM LOCKOUT AND DIAGNOSTIC FEATURES In a typical system, a call for cool is initiated by closing the thermostat contacts. This energizes the 50A55 control and the compressor. The cool delay-to-fan-on period SYSTEM LOCKOUT FEATURES begins. After the delay period ends, the optional elec- tronic air cleaner is energized, and the circulator fan is When system lockout occurs, the gas valve is de-ener- energized at cool speed. After the thermostat is satisfied, gized, the circulator blowe
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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.
