Lennox Dave Signature XP21 Installation Instructions Manual page 25

This performance check is ONLY valid on systems that have clean indoor and outdoor coils, proper airflow over coils,
and correct system refrigerant charge. All components in the system must be functioning properly to correctly perform
compressor operational check. (Accurate measurements are critical to this test as indoor system loading and outdoor
ambient can affect variations between low and high capacity readings).
XP21 Field Operational Checklist
Unit Readings
Compressor
Voltage
Amperage
Condenser Fan motor
Amperage
Temperature
Ambient
Outdoor Coil Discharge Air
Compressor Discharge Line
Indoor Return Air
Indoor Coil Discharge Air
Pressures
Suction (Vapor)
Liquid
Note - Heat pump may have a low ambient control or control that locks in second-stage operation below its set point. It may be necessary to remove a
wire from the control when performing this check.
*** 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.
IMPORTANT
Cooling***
Y1 Expected results
First during Y2 demand
Stage (toggle switch ON)
Same
Higher
Same or Higher
Same
Higher
Higher
Same
Lower
Lower
Higher
Page 25
Y2
Y1
Second
First Stage
Stage
Heating***
Expected results
Y2 Second
during Y2 demand
Stage
(toggle switch ON)
Same
Higher
Same or Higher
Same
Lower
Higher
Same
Higher
Down
Higher
XP21 SERIES