Mitsubishi Electric e Series Service Handbook page 130

[ IX Troubleshooting ]
Problem
The unit has Automatic Start/Stop
stopped during thermistor has tripped.
operation and
does not restart.
The high-pressure
switch has
tripped.1302, 1303
The vacuum protection
has tripped.
1301
The discharge
temperature thermistor
has tripped.
1102
The unit has Overcurrent
stopped during passed through the
operation and compressor.
does not restart. 4250
A water supply cutoff
was detected.
2500, 2501, 2550
The freeze-up
protection function has
tripped.
1503
The unit is in Water temperature is
operation, but the low/high.
water does not
heat up/cool
down.
Water temperature is
high/low.
The unit is mak- The compressor is
ing a great deal of being flooded.
vibrations and
noise.
HWE1417B
Check item
Water temperature is
high.
Water temperature is The setting for the automatic Start/Stop
low. thermistor is too low.
Water temperature is Dirty condenser
not high.
Refrigerant overcharge
Air in the refrigerant circuit
Water flow shortage
Outdoor temperature is Refrigerant undercharge, refrigerant
not low. gas leakage
Dirty evaporator
LEV fault in the main circuit
Clogged strainer
Clogged check valve
Excessive frosting
Suction gas is Refrigerant undercharge, refrigerant
overheated. gas leakage
LEV fault in the main circuit
Clogged strainer
The cooling fan is stopped.
High pressure is too high.
Outdoor temperature is Overload operation
high. Burnt motor
Seized compressor
The pump is operating Water flow shortage
normally.
Flow switch fault
The pump does not Problem with the solenoid contactor for
operate. the pump
Pump fault
Water flow shortage Plate heat exchanger freeze-up
The water flow rate is 4-way valve fault
sufficient.
The water inlet/outlet The water-heating/cooling load is too
temperature differen- high.
tial is normal.
Low refrigerant charge due to a leak.
The water inlet/outlet LEV fault in the main circuit
temperature differen-
tial is small.
Compressor failure
High pressure is too high, or low pres-
sure is too low.
Water flow shortage
Problem with the external devices
LEV fault in the main circuit
- 121 -
Cause
Normal
Change the setting for the automatic Start/
Stop thermistor.
Clean the condenser.
Evacuate the system, and charge the sys-
tem with refrigerant.
Evacuate the system, and charge the sys-
tem with refrigerant.
Secure enough water flow rate.
Perform a leakage test, repair the leaks,
evacuate the system, and charge the refrig-
erant circuit with refrigerant.
Clean the evaporator.
Replace the LEV in the main circuit.
Replace the strainer.
Replace the check valve.
Install a snow hood to keep snow from ac-
cumulating on the unit.
Perform a leakage test, repair the leaks,
evacuate the system, and charge the refrig-
erant circuit with refrigerant.
Replace the LEV in the main circuit.
Replace the strainer.
Check the fan for proper operation, and re-
place it if necessary.
Check the items above and make neces-
sary adjustments so that the suction gas
temperature falls within the specified tem-
perature range.
Reduce the operation load, and check the
operation patterns.
Replace the compressor.
Increase the water flow rate.
Replace the flow switch.
Replace the electromagnetic contactor.
Replace the pump.
Increase the water flow rate.
Replace the 4-way valve.
Install more units
Perform a leakage test, repair the leaks,
evacuate the system, and charge the refrig-
erant circuit with refrigerant.
Replace the LEV in the main circuit.
Replace the compressor.
Operate the units within the specified pres-
sure range.
Increase the water flow rate.
Repair the devices.
Replace the LEV.
Solution
GB