Mitsubishi Electric Mr. Slim PUHZ-P100VKA Service Manual page 37

Abnormal point and detection method
Check code
To find out the detail history (latest) about U9 error, turn ON SW2-1, 2-2 and 2-6.
Detailed
Refer to "9-10. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
codes
Overvoltage error
• Increase in DC bus voltage to
PUHZ-P·VKA: 430 V
01
PUHZ-P·YKA: 760 V
Undervoltage error
• Instantaneous decrease in DC
bus voltage to
PUHZ-P·VKA: 200 V
PUHZ-P·YKA: 350 V
02
U9
(4220)
Input current sensor error/
L1-phase open 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.
04
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
08
circuit board.
OCH670
Case
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 Decrease in power source voltage,
instantaneous stop.
2 Defective converter drive circuit in
outdoor power circuit board (PUHZ-
P·VKA)
3 Defective 52C drive circuit in outdoor
power circuit board
4 Disconnection or loose connection
of rush current protect resistor RS
(PUHZ-P·YKA)
5 Defective rush current protect
resistor RS (PUHZ-P·YKA)
6 Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board (PUHZ-
P·VKA)
7 Power circuit failure on DC supply for
15 V DC output on outdoor controller
circuit board (PUHZ-P·VKA)
1 L1-phase open (PUHZ-P·YKA)
2 Disconnection or loose connection
between TB1 and outdoor noise filter
circuit board (PUHZ-P·YKA)
3 Disconnection or loose connection
of CN5 on the outdoor power circuit
board/CNCT on the outdoor noise filter
board (PUHZ-P·YKA)
4 Defective ACCT (AC current trans)
on the outdoor noise filter circuit
board (PUHZ-P·YKA)
5 Defective input current detection
circuit in outdoor power circuit board
6 Defective outdoor controller 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
37
Judgment and action
1 Check the field facility for the power
supply.
2 Correct the wiring (U . V . W phase) to
compressor. Refer to "9-9. TEST POINT
DIAGRAM (Outdoor power circuit board)".
3 Replace outdoor power circuit board.
4 Check compressor for electrical insula-
tion. Replace compressor.
1 Check the field facility for the power
supply.
2 Replace outdoor power circuit board.
(PUHZ-P·VKA)
3 Replace outdoor power circuit board.
4 Check RS wiring. (PUHZ-P·YKA)
5 Replace RS. (PUHZ-P·YKA)
6 Check CN2 wiring. (PUHZ-P·VKA)
7 Replace outdoor controller circuit board.
(PUHZ-P·VKA)
1 Check the field facility for the power
supply. (PUHZ-P·YKA)
2 Check the wiring between TB1 and out-
door noise filter circuit board. (PUHZ-
P·YKA)
3 Check CN5/CNCT wiring. (PUHZ-
P·YKA)
4 Replace outdoor noise filter circuit
board. (PUHZ-P·YKA)
5 Replace outdoor power circuit board.
6 Replace outdoor controller 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.
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