Error Code
Abnormal point and detection method
Case
Judgment and action
20
U9
Detailed
codes
To find out the details about U9 error, turn ON SW2-1, 2-2, 2-3, 2-4, 2-5 and 2-6 when U9 error occurs.
To find out the detail history (latest) about U9 error, turn ON SW2-1, 2-2, 2-6.
Refer to 8-8.
01
Overvoltage error
• Increase in DC bus voltage to
760V
1
Abnormal increase in power source
voltage
2
Defective outdoor power circuit
board
3
Compressor has a ground fault.
1
Check the field facility for the power supply.
2
Replace outdoor power circuit board.
3
Check compressor for electrical insula-
tion. Replace compressor.
02
Undervoltage error
• Instantaneous decrease in DC
bus voltage to 400V
1
Decrease in power source voltage,
instantaneous stop.
2
Defective 52C drive circuit in
outdoor power circuit board
3
Disconnection or loose connection of
rush current protect resistor RS
4
Defective rush current protect
resistor RS
5
Disconnection or loose connection of
main smoothing capacitor CB1/CB2
1
Check the field facility for the power
supply.
2
Replace outdoor power circuit board.
3
Check RS wiring.
4
Replace RS.
5
Check CB1/CB2 wiring.
04
Input current sensor error/
L1-phase open error
• Decrease in input current
through outdoor unit to 0.1A
only if operation frequency is
more than or equal to 40Hz
or compressor current is more
than or equal to 6A.
1
L1-phase open
2
Disconnection or loose connection
between TB1 and outdoor noise filter
circuit board
3
Disconnection or loose connection of
CN5 on the outdoor power circuit board/
CNCT on the outdoor noise filter board
4
Defective ACCT (AC current trans)
on the outdoor power circuit board
5
Defective input current detection
circuit in outdoor power circuit board
6
Defective outdoor controller circuit
board
1
Check the field facility for the power
supply.
2
Check the wiring between TB1 and out-
door noise filter circuit board.
3
Check CN5/CNCT wiring.
4
Replace outdoor noise filter circuit
board.
5
Replace outdoor power circuit board.
6
Replace outdoor controller circuit board.
08
Abnormal power synchronous
signal
• No input of power synchronous
signal to power circuit board
• Power synchronous signal
of 44 Hz or less, or 65 Hz or
more is detected on power
circuit board.
1
Distortion of power source voltage,
Noise superimposition.
2
Disconnection or loose connection
of earth wiring
3
Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board
4
Defective power synchronous signal
circuit in outdoor controller circuit
board
5
Defective power synchronous signal
circuit in outdoor power circuit board
1
Check the field facility for the power
supply.
2
Check earth wiring.
3
Check CN2 wiring.
4
Replace outdoor controller circuit board.
5
Replace outdoor power circuit board.
10
PFC error (Overvoltage/
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowings
a) Increase of DC bus voltage
to 420V.
b) Decrease in PFC control
voltage to 12V DC or lower
c) Increase in input current to
50A peak
(For models equipped with
single-phase PFC only)
Not applicable for SHW230YKA model.
Check for the switch settings for Model
Select on the outdoor controller circuit
board.
20
PFC/IGBT error
(Undervoltage)
• When Compressor is running,
DC bus voltage stays at 310V or
lower for consecutive 10 seconds
(Single phase model only)
Not applicable for SHW230YKA model.
Check for the switch settings for Model
Select on the outdoor controller circuit
board.
OCH534
