Carrier 69NT40-561-300, Operation And Service Manual

Page: 115 / 174

6–7 T-365
6.14 COMPRESSOR OPERATING IN REVERSE
Condition Possible Cause Remedy/Refer-
ence Section
NOTICE
The compressor may start in reverse for up to 10 seconds to determine correct phase rotation
if required for phase detection.
CAUTION
!
Allowing the scroll compressor to operate in reverse for more than two minutes will result in
internal compressor damage. Turn the start
− stop switch OFF immediately.
Electrical
Incorrect wiring of compressor
Check Incorrect wiring of compressor contactor(s)
Incorrect wiring of current sensor
6.15 ABNORMAL TEMPERATURES
Condition Possible Cause Remedy/Refer-
ence Section
High discharge temperature
Gas Cooler coil dirty Section 7.10.1
Gas Cooler fan rotating backwards Section 7.11
Gas Cooler fan inoperative Section 7.11.1
Refrigerant overcharge or non-condensibles Section 7.3
Discharge service valve partially closed Open
Electronic expansion valve (EEV) control malfunction Section 7.16.1
Failed suction pressure transducer (SPT) or evaporator
pressure transducer (EPT) Replace
Discharge temperature sensor drifting high Replace
Failed economizer expansion valve, economizer coil, or
economizer solenoid valve Replace
Plugged economizer expansion valve, economizer coil, or
economizer solenoid valve Replace
Loose or insufficiently clamped sensor Replace
6.16 ABNORMAL CURRENTS
Condition Possible Cause Remedy/Refer-
ence Section
Unit reads abnormal currents Current sensor wiring Check