Call For Cooling - Lennox SL280UH090V36B Installation Instructions Manual

Troubleshooting: Cooling Sequence of Operation

CALL FOR COOLING

1ST STAGE COOLING
REQUEST RECEIVED
WAIT FOR COMPRESSOR TIMED
OFF DELAY TO EXPIRE
ENERGIZE 1ST STAGE
COOLING CONTACTOR
(COMPRESSOR & FAN)
INDOOR BLOWER 2
SECOND ON DELAY
ENERGIZE INDOOR BLOWER
(LOW COOLING MODE)
ENERGIZE 2ND STAGE
COOLING CONTACTOR
(COMPRESSOR & FAN)
COOLING REQUEST
DE−ENERGIZE 2ND
STAGE COOLING
(COMPRESSOR & FAN)
COOLING REQUEST
DE−ENERGIZE 1ST
STAGE COOLING
(COMPRESSOR & FAN)
DE−ENERGIZE INDOOR
1
1
2
MAINTAIN INDOOR
BLOWER
(LOW COOLING MODE)
1
2ND STAGE
NO
COOLING
REQUEST?
YES YES
ENERGIZE INDOOR BLOWER
(HIGH COOLING MODE)
2ND STAGE
MAINTAIN INDOOR BLOWER
YES
(HIGH COOLING MODE)
STILL ACTIVE?
NO
CONTACTOR
1ST STAGE
ENERGIZE AND MAINTAIN
YES
INDOOR BLOWER AT
STILL ACTIVE?
(LOW COOLING MODE)
NO
CONTACTOR
1
CONTROL WILL NOT RESPOND TO A 2ND STAGE COOLING REQUEST UNLESS A 1ST STAGE
COOLING REQUEST IS ACTIVE.
INDOOR BLOWER LOW COOLING MODE AND HIGH COOLING MODE HAVE SPECIFIC ON, OFF
2
AND SPEED RAMPING PROFILES. THE SPECIFIC PROFILE IS SELECTED USING THE
2
BLOWER
DIP SWITCHES ON THE CONROL.
1
YES
YES
1ST STAGE
COOLING REQUEST
STILL ACTIVE?
2
NO
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