Midea RSJ-420/PZN1-H - Page 48

MCAC-HTSM-201506 Midea R410A Direct Heating Commercial Heat Pump 50Hz Technical Manual
48
2. Damages of the compressor inner
components.
Change the compressor.
Water pump not operated or abnormal operated
Possible reason
Detect and settle measure
1. Power errors.
Check and repair.
2. Relay error.
Change the relay.
3. There is gas in the water pipe.
Drain off the gas.
Compressor ON and OFF frequently
Possible reason
Detect and settle measure
1. Bad circulation of water system.
Blocked the water system or has air in the water system.
Check the water pump, valves, pipeline, and clean the
water filter or drain off the air.
2. Low load.
Adjust the load or add stored energy device.
Compressor operated with no heating
Possible reason
Detect and settle measure
1. Refrigerant leakage.
Check, repair and replenish the refrigerant.
2. Compressor error.
Change the compressor.
No obvious heating effect of the unit
Possible reason
Detect and settle measure
1. Bad thermal insulation of water
system.
Enlarge the thermal insulation of the system.
2. Bad heat exchanging of evaporator.
Check the air inlet and outlet whether are normal and clean
the evaporator.
3. Lack of refrigerant.
Check whether has refrigerant leakage.
4. The water side heat exchanger has
blocked.
Clean or change the heat exchanger.
In case the unit runs under abnormal condition, failure protection code will display on both digital tube
on PCB board and wired controller. The indicator on the wired controller will flash with 5Hz. The
display codes are shown in the following table: