Lennox LDT DUAL FUEL Series - Unit Sequence of Operation; Cooling Sequence of Operation

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LDT078-150H SEQUENCE OF OPERATION
Power:
1 - 
Unit Controller which provides 24VAC to the unit cooling, heating and blower controls.
2 - Line voltage is also routed to compressor crankcase heaters, compressor contactors, the blower motor, condenser fan relays and exhaust fan relays.
Blower Operation:
3 - 
4 - 
 
6 - 
First Stage Cooling Demand (compressor B1)
7 - 
8 - 
9 - N.O. contacts K1-1 close energizing compressor B1. Crankcase heater HR1 is de-energized.
10 - 
Second Stage Cooling Demand (compressor B2)
11 - 
12 - 
13 - N.O. contacts K2-1 close energizing compressor B2. Crankcase heater HR2 is de-energized.
3nd Stage Cooling (compressor B1 in full load and compressor 2 is energized)
14 - 
