Westinghouse WHU09CTA21S, Service Manual, Page: 39 / 90

Fault
code
Fault
d
escription
Possible
r
eason
s for a
bnormality
How to
d
eal
w
ith R
emarks
46 IPM and control board
communication fault
1. The cable between the control
board and the driver board is
connect ed loose ly ;
2. The cable between the control
board and the driver board
fail s ;
3. The driver board fail s
；
4. The control board fail s .
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.
47
Too high d ischarge
temperature fault
1.
2.
The refrigerant of the unit is not
enough;
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.
2.
Check the welding point to
confirm whether the unit has
leakage point, and add some
refrigerant ;
Add some refrigerant refer ring
to the installation user manual;
3. Replace the throttling service
(such as capillary, expansion
valve) ;
4. Normally protection.
48
T he outdoor DC
fan motor fault
(upper fan motor)
1. The connecting wiring of the up
DC fan motor is loose;
2. The cord of the up per DC fan
motor fails;
3. The up per DC fan motor fails ;
4. The drive circuit of the up per DC
fan motor fail s ;
5. The outdoor fan has been
blocked.
1. Reconnect the wiring of the up
DC fan motor;
2. Replace the up per DC fan motor;
3. Replace the up per 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.
49
T he outdoor DC
fan motor fault
(down fan motor)
1.
2.
The connecting wiring of the
down DC fan motor is loose;
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 fail s ;
5. The outdoor fan has been
blocked.
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.
91
The unit turn off due to
the IPM
board over heating
fault
1.
2.
The outdoor ambient temp. is too
high;
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.
1.
2.
Normal protection;
Check the fan capacitor, and
replace the fan capacitor if it is
failure;
3. Reinstalled the outdoor unit
refer to the installation user
manual;
4. Normal protection.
96
Lacking of
refrigerant
The refrigerant of the unit is not
enough .
Discharge the refrigerant and
charge the refrigerant
refer ring to the rating label .
97
4-way valve
commutation failure
fault
1. The connecting wiring of the 4-
way valve coil is loose;
2. The 4-way valve coil fail s ;
3. The 4-way valve fail s ;
4. The driver board of the 4-way
valve fails.
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
4-way valve.
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