22
Maintenance
■
Common Faults and Troubleshooting
S/N Fault description Possible cause
Troubleshooting
Remarks
8
Fault in flow
switch
1.
Air found in the water system
Discharge air via the exhaust
valve
Cooling/heating
2.
Water-side heat exchanger scaling
or with foreign matters inside
Clean up the incrustation scale
3.
Poor switch
Replace the target flow switch
4.
Unevenly distributed flow in water
pipelines
Adjust the flow in water pipelines
via the shut-off valve
5.
Out-of-service water pump
Machine installation must be
ganged
6.
Insufficient types of water pumps
Check it and try to fix it
9
Fault in
communication of
wired controller
1.
Incorrect unit numbering
Check the unit numbering, and
correct it.
Cooling/heating
2.
Incorrect connection of
communication wires
Check the order of connection of
communication wires
3.
Damaged PCB
Replace the PCB
4.
Poor wired controller
Replace the wired controller
10
Over-current fault
of compressor
1.
High exhaust pressure and high
suction pressure
Refer to “High Exhaust Pressure”
and “High Suction Pressure”
Cooling/heating
2.
High or low voltage, single phase or
phase imbalance
Check the power supply
3.
Short circuit in motor or terminal
Check the terminal connections
11
Open circuit in
low-pressure
sensor
1.
Damaged sensor
Replace the sensor
Cooling/heating
2.
Poor connection of sensor
Reconnect the sensor