Midea RSJ-420/PZN1-H - Page 47

Midea R410A Direct Heating Commercial Heat Pump 50Hz Technical Manual MCAC-HTSM-201506
47
Need to check again
Phenomena
Cause
Stop operation or drive up
automatically
Detect the timer whether be given wrong operation.
Detect anti-freezing mode is opened.
No operation
Whether the power is cut.
Whether the manual power supply switch is off.
Whether the fuse is broken.
Whether the protection device works. (Operation lamp is
lightened.)
Whether it is the time set. (Operation lamp is lightened.)
Compressor is unable to drive
Possible reason
Detect and settle measure
1. Power errors.
Connected with wrong phase sequence.
2. Wire connection is loosening.
Check and fasten again.
3. Relay or fuse errors.
Check and repair.
4. Compressor errors.
Change the compressor.
Fan has loud noise
Possible reason
Detect and settle measure
1. Fixing screw of the fan is loosening.
Re-fasten the fixing screw of the fan.
2. Fan blade touched the cover shell
or screen
Check and adjust.
3. The fan operated unsteadily.
Change the fan.
Abnormal noise given out from compressor
Possible reason
Detect and settle measure
1. Liquid refrigerant flows into
compressor and produces liquid
strikes.
Check the EXV, and whether the temperature sensor
loosen and repair.