Troubleshooting - Mitsubishi Electric CAHV-P500YA-HPB 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
1. If a problem occurs, please check the following. If a protection device has tripped and brought the unit to stop (when an error
code is blinking on the LED), 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.
HWE10060
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 Short-circuited circuit or ground fault
resistance and the
earth resistance.
Protection devices INV board problem
have not tripped.
Noise filter board problem
High-pressure cutout Abnormal
switch has tripped. high
AHP1 pressure
The discharge LEV fault in the main circuit
temperature thermistor
has tripped.
Injection LEV fault
AC61
Injection solenoid valve fault
Refrigerant gas leakage
Refrigerant undercharge
A thermistor error was Broken or short-circuited thermistor
detected. wiring
5101~5115
Overcurrent passed Compressor motor
through the compres-
sor.
Overload operation
4250
Seized compressor shaft
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
The flow switch has The flow switch wiring is not connect-
tripped. ed.
Water flow shortage
Flow switch contact failure
Automatic Start/Stop The water temperature has reached
thermistor has tripped. above the preset temperature.
The motor whines, but Contact failure at a connector terminal
will not turn.
Loose wire connection
Seized compressor or fan bearing
High-pressure is too high.
A momentary overcur- Burned, short-circuited, or ground
rent was detected. faulted motor
- 113 -
Cause
Switch on the power.
Connect the pump interlock circuit wiring to
the system.
Connect the flow switch wiring to the sys-
tem.
Resolve the cause, and replace the fuse.
Repair or replace the INV board.
Repair or replace the noise filter board.
Dirty condenser Clean the condenser.
(scaling formation)
Air in the refrigerant circuit Vacuum the refrigerant circuit, and charge
it with refrigerant.
Water flow shortage Secure enough water flow rate.
Replace the LEV in the main circuit.
Replace the injection LEV.
Replace the solenoid valve.
Leakage test
Repair the cause of refrigerant shortage,
evacuate the system, and charge the refrig-
erant circuit with refrigerant.
Check the thermistor wiring for broken con-
nections or short circuit.
Replace the thermistor.
Replace the compressor.
Check the operation patterns.
Replace the compressor.
Connect the pump interlock wiring.
Operate the pump.
Replace the solenoid contactor.
Connect the flow switch wiring to the sys-
tem.
Increase the water flow rate.
Polish the contact point.
Normal
Polish the contact point.
Tighten the wire connection.
Disassemble the compressor or the fan,
and repair as necessary.
Check the operation patterns.
Replace the compressor, and clean the re-
frigerant circuit.
Solution
GB