g43 service manual - Heating and Air Parts

COOLING SEQUENCE OF OPERATIONIgnition Control 78M47 / 100973−01NORMAL COOLING MODEPOWER ONABNORMAL COOLING MODEIGNITION CONTROL MAIN POWER ON.CONTROL SELF DIAGNOSTIC CHECK.IS CONTROL OPERATING NORMALLY?YESIS THERE A PROPER GROUND?YESIS POLARITY CORRECT?YESIS VOLTAGEABOVE 90 VOLTS?YESROLLOUT SWITCH MONITORED CONTINUOUSLY.IS ROLLOUT SWITCH CLOSED?YESNONONONONOGAS VALVE OFF. COMBUSTION AIR INDUCER OFF.INDOOR BLOWER OFF WITH NORMAL DELAY.SIGNAL CIRCUIT BOARD FAILURE AT LED.INTERRUPT MAIN POWER TO RESET CONTROL.SIGNAL IMPROPER GROUND AT LED.CONTROL WILL CONTINUE TO CALL FOR COOLINGIN THIS CONDITION.SIGNAL POLARITY REVERSED AT LED. CONTROLWILL CONTINUE TO CALL FOR COOLING IN THISCONDITION.LED SIGNALS LOW VOLTAGE. CONTROL WILLCONTINUE TO CALL FOR COOLINGIN THIS CONDITION.GAS VALVE OFF. COMBUSTION AIR INDUCER ON.INDOOR BLOWER ON.SIGNAL ROLL-OUT SWITCH OPEN AT LED.SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSESAND MAIN POWER IS INTERRUPTED OR THERMOSTATIS CYCLED OFF/ON FOR 1 SEC. MINIMUM.LED: SLOW FLASH RATE REMAINS UNCHANGEDTHROUGHOUT COOLING CYCLE.THERMOSTAT CALLS FOR COOLING.COMPRESSOR CONTACTOR AND SYSTEM FANENERGIZED WITH 2-SECOND DELAY(COOLING SPEED). EAC TERM. ENERGIZED.THERMOSTAT OPENS.COMPRESSOR OFF.SYSTEM FAN AND EAC TERM. OFFWITH 0-SECOND DELAY.UNITS WITH BOARD 100973−01 − SYSTEMFAN OFF AFTER 45 SECOND DELAYPage 48