Page 42
506238−01 06/09
Field Operational Checklist
Unit Readings
Cooling***
Heating***
Y1
First
Stage
Expected results
during Y2 demand
(Toggle switch On)
Y2
Second
Stage
Y1
First Stage
Expected results
during Y2 demand
(Toggle switch On)
Y2 Second
Stage
Compressor
Voltage
Same
Same
Amperage
Higher
Higher
Condenser Fan motor
Amperage
Same or Higher
Same or Higher
Temperature
Ambient
Same
Same
Outdoor Coil Discharge Air
Higher
Lower
Compressor Discharge Line
Higher
Higher
Indoor Return Air
Same
Same
Indoor Coil Discharge Air
Lower
Higher
Pressures
Suction (Vapor)
Lower
Down
Liquid
Higher
Higher
NOTE Heat pump may have a low ambient control or DCB that locks in second−stage below its set point. It may be necessary to remove a wire
from the control when performing this checklist.
**
On the XPG20 units, the Lennox System Operational Module controls the second−stage solenoid coil in compressor.
***
Cooling Mode Operation − Block outdoor coil to maintain a minimum of 375 psig during testing. Heating Mode Operation − Block indoor coil to
maintain a minimum of 375 psig during testing.