Abnormal point and detection method
Case
Judgment and action
Check code
39
U9
(4220)
Detailed
codes
To find out the details about U9 error, turn ON SW2-1, 2-2, 2-3, 2-4, 2-5, 2-6 when U9 error occurs.
To find out the detail history (latest) about U9 error, turn ON SW2-1, 2-2, 2-6. For more detail, refer to "10-10.
FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
01
Overvoltage error
• Increase in DC bus voltage to
VHA
model: 400V
YHA
model: 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 "10-9. TEST
POINT DIAGRAM
(Outdoor power
circuit board)".
3
Replace outdoor power circuit board.
4
Check compressor for electrical
insulation. Replace compressor.
02
Undervoltage error
• Instantaneous decrease in DC
bus voltage to
VHA model
:
200V
YHA model
:
350V
1
Decrease in power source voltage,
instantaneous stop.
2
Disconnection or loose connection of
CN52C on the outdoor power circuit
board/controller circuit board (VHA)
3
Defective converter drive circuit of
outdoor power circuit board (VHA)
4
Defective 52C drive circuit in outdoor
power circuit board (VHA)/ noise filter
circuit board (YHA)
5
Disconnection or loose connection of
rush current protect resistor RS (YHA)
6
Defective rush current protect resistor
RS
(YHA)
7
Disconnection or loose connection of
main smoothing capacitor CB(VHA),
CB1, CB2 (SP125/140YHA)
8
Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board (VHA)
9
Power circuit failure on DC supply for
18V DC output on outdoor controller
circuit board (VHA)
1
Check the field facility for the power
supply.
2
Check CN52C wiring. (VHA)
3
Replace outdoor power circuit board.
(VHA)
4
Replace outdoor power circuit board. (VHA)
Replace outdoor noise filter circuit board
(YHA)
5
Check RS wiring. (YHA)
6
Replace RS. (YHA)
7
Check CB or CB1,CB2 wiring.
(VHA, SP125/140YHA)
8
Check CN2 wiring.(VHA)
9
Replace outdoor controller circuit board.
(VHA)
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 (YHA)
2
Disconnection or loose connection
between TB1 and outdoor noise filter
circuit board (YHA)
3
Disconnection or loose connection
of CN5 on the outdoor power circuit
board/CNCT on the outdoor noise filter
board(YHA)
4
Defective ACCT(AC current trans) on
the outdoor noise filter circuit board
(YHA)
5
Defective input current detection
circuit of outdoor power circuit board
6
Defective outdoor controller circuit board
1
Check the field facility for the power
supply. (YHA)
2
Check the wiring between TB1 and
outdoor noise filter circuit board (YHA)
3
Check CN5/CNCT wiring. (YHA)
4
Replace outdoor noise filter circuit
board. (YHA)
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 synchrous signal
circuit in outdoor controller circuit board
5
Defective power synchrous 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.
OCH566A
