25
U9
(4220)
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 and 2-6.
Refer to "9-7. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
01
Overvoltage error
• Increase in DC bus voltage to
SW75,100V,SHW80, 112V: 430V
SW75,100Y,SHW80, 112Y: 760V
1
Abnormal increase in power source
voltage
2
Disconnection of compressor wiring
3
Defective outdoor power circuit
board
4
Compressor has a ground fault.
1
Check the field facility for the power
supply.
2
Correct the wiring (U.V.W phase) to
compressor. Refer to "9-7. FUNCTION
OF SWITCHES, CONNECTORS AND
JUMPERS". (Outdoor power circuit board).
3
Replace outdoor power circuit board.
4
Check compressor for electrical insula-
tion. Replace compressor.
02
Undervoltage error
• Instantaneous decrease in DC
bus voltage to
SW75, 100V, SHW80, 112V: 200V
SW75, 100Y, SHW80, 112Y: 350V
1
Decrease in power source voltage,
instantaneous stop
2
Defective converter drive circuit in
outdoor power circuit board (SW-V,
SHW-V)
3
Defective 52C drive circuit in outdoor
power circuit board
4
Defective outdoor converter circuit
board (SW-Y, SHW-Y)
5
Disconnection or loose connection of
rush current protect resistor RS (SW-
Y, SHW-Y)
6
Defective rush current protect
resistor RS (SW-Y, SHW-Y)
7
Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board (SW-V,
SHW-V)
8
Power circuit failure on DC supply for
15 V DC output on outdoor controller
circuit board (SW-V, SHW-V)
1
Check the field facility for the power
supply.
2
Replace outdoor power circuit board.
(SW-V, SHW-V)
3
Replace outdoor power circuit board.
4
Replace outdoor converter circuit
board. (SW-Y, SHW-Y)
5
Check RS wiring. (SW-Y, SHW-Y)
6
Replace RS. (SW-Y, SHW-Y)
7
Check CN2 wiring. (SW-V, SHW-V)
8
Replace outdoor controller circuit board.
(SW-V, SHW-V)
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 (SW-Y, SHW-Y)
2
Disconnection or loose connection
between TB1 and outdoor noise filter
circuit board (SW-Y, SHW-Y)
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 noise filter circuit board
(SW-Y, SHW-Y)
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. (SW-Y, SHW-Y)
2
Check the wiring between TB1 and out-
door noise filter circuit board. (SW-Y,
SHW-Y)
3
Check CN5/CNCT wiring. (SW-Y, SHW-
Y)
4
Replace outdoor noise filter circuit
board. (SW-Y, SHW-Y)
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.
Continue to the next page
Abnormal point and detection method
Cause
Judgment and action
Check code
OCH651
