Lennox G43UF SERIES Unit Information page 48

NORMAL COOLING MODE
POWER ON
IGNITION CONTROL MAIN POWER ON.
CONTROL SELF DIAGNOSTIC CHECK.
IS CONTROL OPERATING NORMALLY?
YES
IS THERE A PROPER GROUND?
YES
IS POLARITY CORRECT?
YES
IS VOLTAGE
ABOVE 90 VOLTS?
YES
ROLLOUT SWITCH MONITORED CONTINUOUSLY.
IS ROLLOUT SWITCH CLOSED?
YES
LED: SLOW FLASH RATE REMAINS UNCHANGED
THROUGHOUT COOLING CYCLE.
THERMOSTAT CALLS FOR COOLING.
COMPRESSOR CONTACTOR AND SYSTEM FAN
ENERGIZED WITH 2-SECOND DELAY
(COOLING SPEED). EAC TERM. ENERGIZED.
THERMOSTAT OPENS.
COMPRESSOR OFF.
SYSTEM FAN AND EAC TERM. OFF
WITH 0-SECOND DELAY.
UNITS WITH BOARD 100973−01 − SYSTEM
FAN OFF AFTER 45 SECOND DELAY
COOLING SEQUENCE OF OPERATION
Ignition Control 78M47 / 100973−01
NO
NO
NO
NO
NO
Page 48
ABNORMAL COOLING MODE
GAS 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 COOLING
IN THIS CONDITION.
SIGNAL POLARITY REVERSED AT LED. CONTROL
WILL CONTINUE TO CALL FOR COOLING IN THIS
CONDITION.
LED SIGNALS LOW VOLTAGE. CONTROL WILL
CONTINUE TO CALL FOR COOLING
IN THIS CONDITION.
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.
INDOOR BLOWER ON.
SIGNAL ROLL-OUT SWITCH OPEN AT LED.
SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES
AND MAIN POWER IS INTERRUPTED OR THERMOSTAT
IS CYCLED OFF/ON FOR 1 SEC. MINIMUM.