Service Manual

35
OCH636B
Check code Abnormal points and detection method Cause judgment and action
U9
(4220)
Detailed
codes
To find out the detail history (latest) about U9 error, turn ON SW2-1, 2-2, and 2-6.
Refer to "10-10. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
01
Overvoltage error
• Increase in DC bus voltage to:
A12, 18N: 400 V
A24, 30, 36, 42N: 430 V
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 200 V
1 Decrease in power source
voltage, instantaneous stop.
2 Defective converter drive circuit
in outdoor power circuit board
3 Defective 52C drive circuit in
outdoor power circuit board
4 Disconnection or loose
connection of CN2 on the
outdoor power circuit board/
controller circuit board
5 Power circuit failure on DC
supply for 15 V DC output on
outdoor controller circuit board
1 Check the field facility for the power supply.
2 Replace outdoor power circuit board.
3 Replace outdoor power circuit board.
4 Check CN2 wiring.
5 Replace outdoor controller circuit board.
04
Input current sensor error
• Decrease in input current
through outdoor unit to 0.1 A
only if operation frequency is
more than or equal to 40 Hz
or compressor current is more
than or equal to 6 A.
1 Defective input current
detection circuit in outdoor
power circuit board
2 Defective outdoor controller
circuit board
1 Replace outdoor power circuit board.
2 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 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. (A24–42N only)
4 Replace outdoor controller circuit board.
5 Replace outdoor power circuit board.
(A24–42N only)
10
PFC error (Overvoltage/
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowing:
a) Increase of DC bus voltage
as follows:
A12, 18N: 400 V
A24, 30, 36, 42N: 430 V
b)
Decrease in PFC control
voltage to 13 V DC or lower
(A24–42N only)
c) Increase in input current as
follows:
A12, 18N: 50 A peak
A24, 30N: 42 A peak
A36, 42N: 62 A peak
1 Abnormal increase in power
source voltage
2 Decrease in power source
voltage, instantaneous stop
3 Disconnection of compressor
wiring
4 Misconnection of reactor (DCL)
5 Defective outdoor power circuit
board
6 Defective reactor (DCL)
7 Disconnection or loose
connection of CN2 on the
outdoor power circuit board/
controller circuit board
12 Check the field facility for the power supply.
3 Correct the wiring (U·V·W phase) to
compressor.
Refer to "10-9. TEST POINT
DIAGRAM".
4 Correct the wiring (U·V·W phase) or reactor
(DCL). (A24–42N only)
5 Replace outdoor power circuit board.
6 Replace reactor (DCL). (A24–42N only)
7 Check CN2 wiring. (A24–42N only)