Westinghouse WHM24DMA21S Service Manual page 35

Fault
Fault description
code
45 IPM fault
IPM and control board
46
communication fault
Too high discharge
47
temperature fault
The outdoor DC
48 fan motor fault
(upper fan motor)
The outdoor DC
fan motor fault
49
(down fan motor)
The unit turn off due to
91 the IPM
board over heating
fault
96
Lacking of refrigerant
4-way valve
97 commutation failure
fault
Possible reasons for abnormality
There are many reasons for this
failure. You can check the driver
board fault LED to further
the fault code of the drive board and
to learn about what leads to the fault
and how to operate it. Specific
information can be seen in table 2,
table 3.
1.The cable between the control
board and the driver board is
connected loosely;
2.The cable between the control
board and the driver board
fails;
3.The driver board fails；
4.The control board fails.
1. The refrigerant of the unit is not
enough;
2.The refrigerant of the unit is not
enough due to that the
installation pipe is longer;
3.Throttling service fails;
4.The outdoor ambient temperature
is too high.
1.The connecting wiring of the up
DC fan motor is loose;
2.The cord of the upper DC fan
motor fails;
3.The upper DC fan motor fails;
4.The drive circuit of the upper DC
fan motor fails;
5.The outdoor fan has been
blocked.
1. The connecting wiring of the
down DC fan motor is loose;
2. The cord of the down DC fan
motor fails;
3. The down DC fan motor fails;
4. The drive circuit of the down DC
fan motor fails;
5. The outdoor fan has been
blocked.
1. The outdoor ambient temp. is
too high;
2. The speed of the out fan
motor is too low if the fan motor
is AC fan motor;
3. The outdoor unit is not installed
in accordance with the standard;
4.The supply power is too low.
The refrigerant of the unit is not
enough.
1.The connecting wiring of the 4-
way valve coil is loose;
2.The 4-way valve coil fails;
3.The 4-way valve fails;
4.The driver board of the 4-way
valve fails.
How to deal with
analyze
See attached "analysis of the
driving board fault".
1.Reconnect the cable between
the control board and the
driver board;
2.Replace the communication
cable between the control
board and the driver board;
3.Replace the driver board;
4.Replace the control board.
1.Check the welding point to
confirm whether the unit has
leakage point, and then add
some refrigerant;
2.Add some refrigerant referring
to the installation user manual;
3.Replace the throttling service
(such as capillary, expansion
valve);
4.Normal protection.
1.Reconnect the wiring of the up
DC fan motor;
2.Replace the upper DC fan motor;
3.Replace the upper DC fan motor;
4.Replace the driver board of the
fan motor;
5.Check the outdoor fan and ensure
the outdoor fan can run normally.
1. Reconnect the wiring of the
down DC fan motor;
2. Replace the down DC fan
motor;
3. Replace the down DC fan
motor;
4. Replace the driver board of
the fan motor;
5. Check the outdoor fan and
ensure the outdoor fan can run
normally.
1. Normal protection;
2. Check the fan capacitor,
and replace the fan
capacitor if it is a failure;
3. Reinstalled the outdoor unit
referring to the installation
user manual;
4. Normal protection.
Discharge the refrigerant and
charge the refrigerant
referring to the rating label.
1. Reconnect the wiring of the
4-way valve;
2. Replace the 4-way valve coil;
3. Replace the 4-way valve;
4. Replace the driver board of
the way valve.
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Remarks