Lennox International Inc G50UH-48C-110 Iscontrol.Toperatingo Snormally?O,A .Os ,Oo. Ok, Y sJ

SURELIGHT®CONTROL

COOLINGSEQUENCEOF OPERATION

NORMALCOOLING

MODE

ABNORMALCOOLING MODE

I

POWER ON

l

I

IGNITIONCONTROLMA,POWERON

I

I

GAS VALVE OFF, COMBUSTION AIR INDUCER OFR

ISCONTROL.TOPERATINGO SNORMALLY?O,A .OS ,OO. OK

INDOOR BLOWER OFF WITH NORMAL DELAY.

SIGNAL CIRCUIT BOARD FAILURE AT LED.

Y sJ

INTERRUPT MAIN POWER TO RESET CONTROL,

I

,sPOLARITYREVERSED? LED_FLASHLEDIFASTSLOWFLASHI2

/

LED#1 AND

LED#2

NO

ALTERNATING

FAST

I

NO

_

__

I YESJ Is VOLTAGE

_

LED#1 AND LED#2 ALTERNATING FAST

FLASH. SIGNAL

_

IS THERE

FLASH. SIGNAL HOLDS UNTIL VOLTAGE

I HOLDS UNTIL

UNIT IS I_1

PROPER GROUND? I_IABOVE

75 VOLTS?

I_'

RISES ABOVE

75 VOLTS.

[PROPERLY

GROUND.

I

I

• NO I GAS VALVE OFF COMBUSTION

AIR INDUCER OFF

I ROLLOUT

SWITCH

MONITORED

CONTINUOUSLY.

_

INDOOR

BLOWER

OFF WITH

NORMAL

DELAY.

IS ROLLOUT SWITCH

CLOSED?

I_--I

SIGNAL

CIRCUIT

BOARD FAILURE

AT LED,

YESl

-

ISEQUENCEHOLDS UNTIL ROLLOUT SWITCH CLOSES.

t

I CHECK TO ENSURE GAS VALVE IS DE-ENERGIZED.

S GAS VALVE OFF?

I LED:SLOWTHROUGHOUTFLASHRATEREMAINSUNCHANGEDCOOLING CYCLE. I

I THERMOSTAT CALLS FOR COOLING. I

COMPRESSOR CONTACTOR IS ENERGIZED,

INDOOR BLOWER ON COOL SPEED AND EAC

TERM NAL S ENERG ZED AFTER 2-SECOND DELAY,

I

I

I

THERMOSTAT OPENS.		I
COMPRESSOR	OFF.	I
SYSTEM FAN AND EAC	TERM, OFF	I
WITH 2 OR 45-SECOND	DELAY,	I

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