Overvoltage Error; Undervoltage Error; Input Current Sensor Error/L1-Phase Open Error - Mitsubishi Electric PUHZ-SHW230YKA2 Service Manual

Abnormal point and detection method
Check Code
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.
Detailed
Refer to "8-8. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
codes

Overvoltage error

• Increase in DC bus voltage to
760 V
01

Undervoltage error

• Instantaneous decrease in DC
bus voltage to 400 V
02
U9
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 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.
OCH594B
Case
1 Abnormal increase in power source
voltage
2 Defective outdoor power circuit
board
3 Compressor has a ground fault.
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
(Only for YKA2/YKA2R1 type)
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 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
(Only for YKA2/YKA2R1 type)
21
Judgment and action
1 Check the field facility for the power supply.
2 Replace outdoor power circuit board.
3 Check compressor for electrical insula-
tion. Replace compressor.
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.
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.
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.