Allied Air A97USMV Installation Instructions Manual page 71

Troubleshooting : Cooling Sequence of Operation
507028-03
CALL FOR COOLING
5
1st Stage Cooling
Request Received
Energize 1st Stage
Cooling Contactor
(Compressor & Fan)
Indoor Blower On
After 2-second delay
Energize Indoor Blower
(Per Ramping Profile)
1
2nd Stage
Cooling
Request?
YES YES
Energize 2nd Stage
Energize Indoor Blower
Cooling Contactor
(High Cooling mode)
(Compressor & Fan)
2nd Stage
Cooling Request
Still Active?
NO
De-Energize 2nd
Stage Cooling
Contactor
(Compressor & Fan)
1st Stage
Cooling Request
Still Active?
NO
De-Energize 1st
Stage Cooling
Contactor
(Compressor & Fan)
De-Energize Indoor Blower
Per Ramping Profile
1
2
NO Cooling Request
2
Maintain Indoor Blower
YES
(High Cooling mode)
Energize and
Maintain Indoor Blower at
YES
Low Cooling mode
2
Issue 1622
YES
1st Stage
Still Active?
NO
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