Download  Print this page

Troubleshooting - Mitsubishi Electric CAHV-P500YA-HPB Service Handbook

Hot water heat pump.
Hide thumbs


[ 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.
The unit does not
The fuse in the control
box is not blown.
The fuse in the control
box is blown.
The compressor does
not operate.
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.
The flow switch wiring is not connect-
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
switch has tripped.
The discharge
LEV fault in the main circuit
temperature thermistor
has tripped.
Injection LEV fault
Injection solenoid valve fault
Refrigerant gas leakage
Refrigerant undercharge
A thermistor error was
Broken or short-circuited thermistor
Overcurrent passed
Compressor motor
through the compres-
Overload operation
Seized compressor shaft
The pump interlock has
The pump interlock circuit is not con-
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-
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 -
Switch on the power.
Connect the pump interlock circuit wiring to
the system.
Connect the flow switch wiring to the sys-
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-
Increase the water flow rate.
Polish the contact point.
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.


Table of Contents

   Also See for Mitsubishi Electric CAHV-P500YA-HPB

Comments to this Manuals

Symbols: 0
Latest comments: