Troubleshooting - Mitsubishi Electric e Series Service Handbook

[ IX Troubleshooting ]

[2] Troubleshooting

Troubleshooting according to the remote controller malfunction or the external input error
Both for MA remote controller and ME remote controller
Troubleshooting must be performed only by personnel certified by Mitsubishi Electric.
1. Diagnosing Problems for which No Error Codes Are Available
If a problem occurs, please check the following. If a protection device has tripped and brought the unit to stop, resolve the
cause of the error before resuming operation.
Resuming operation without removing the causes of an error may damage the unit and its components.
Problem
The unit does not The fuse in the control
operate. box is not blown.
The fuse in the control
box is blown.
The compressor does
not operate.
Automatic Start/Stop
thermistor has tripped.
The unit is in op- Water temperature is
eration, but the low.
water does not
heat up.
(Heating)
Water temperature is
high.
The unit is in op- Water temperature is
eration, but the low.
water does not
heat up.
Water temperature is
(Cooling)
high.
HWE20010
Check item
The power lamp on the The main power is not turned on.
circuit board is not lit.
The power lamp on the The pump interlock circuit is not con-
circuit board is lit. nected.
The flow switch wiring is not connect-
ed.
Measure the circuit re- Short-circuited circuit or ground fault Resolve the cause, and replace the fuse.
sistance and the earth
resistance.
The pump interlock has The pump interlock circuit is not con-
tripped. nected.
The water pump is not operating.
Problem with the solenoid contactor
for the pump
Water temperature is The setting for the automatic Start/
high. Stop thermistor is too high.
(Cooling)
Water temperature is The setting for the automatic Start/
low. Stop thermistor is too low.
(Heating)
The water inlet/outlet The water-heating load is too high.
temperature differential
Low refrigerant charge due to a leak. Perform a leakage test, repair the leaks, evacuate
is normal.
The water inlet/outlet LEV fault in the main circuit
temperature differential
Compressor failure
is small.
High pressure is too high, or low pres-
sure is too low.
- Water flow shortage
Problem with the external devices
- Water flow shortage
Problem with the external devices
The water inlet/outlet The water-cooling load is too high.
temperature differential
Low refrigerant charge due to a leak. Perform a leakage test, repair the leaks, evacuate
is normal.
The water inlet/outlet LEV fault in the main circuit
temperature differential
Compressor failure
is small.
High pressure is too high, or low pres-
sure is too low.
Cause
- 114 -
Solution
Switch on the power.
Connect the pump interlock circuit wiring to the
system.
Connect the flow switch wiring to the system.
Connect the pump interlock wiring.
Operate the pump.
Replace the solenoid contactor.
Change the setting for the automatic Start/Stop
thermistor.
Change the setting for the automatic Start/Stop
thermistor.
Install more units.
the system, and charge the refrigerant circuit with
refrigerant.
Replace the LEV in the main circuit.
Replace the compressor.
Operate the units within the specified pressure
range.
Increase the water flow rate.
Repair the devices.
Increase the water flow rate.
Repair the devices.
Install more units.
the system, and charge the refrigerant circuit with
refrigerant.
Replace the LEV in the main circuit.
Replace the compressor.
Operate the units within the specified pressure
range.
GB