Mitsubishi Electric Mr.SLIM PUZ-ZM200YKA Service Manual page 39

Check Code Abnormal points and detection method
To find out the detail history (latest) about U9 error, turn ON SW2-1, 2-2 and 2-6.
Detailed
codes
Refer to "10-10. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
Overvoltage error
• Increase in DC bus voltage to
M200/250Y: 760 V
01
Undervoltage error
• Instantaneous decrease in DC
bus voltage to
M200/250Y: 400 V
02
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
04 than or equal to 6 A.
U9
(4220)
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
08
more is detected on power
circuit board.
PFC error (Overvoltage/
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowing:
a) Increase of DC bus voltage
to 420 V.
10
b) Decrease in PFC control
voltage to 12 V DC or lower.
c) Increase in input current
to 50 A peak. (For models
equipped with single-phase
PFC only)
PFC/IGBT error (Undervoltage)
• When Compressor is running,
DC bus voltage stays at 310V
20
or lower for consecutive 10
seconds
OCH738
Cause
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 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
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 noise filter 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
Not applicable for M200/250Y model.
Not applicable for M200/250Y model.
39
Judgment and action
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 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.
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.
Check the switch setting for Model Select
on the outdoor controller circuit board.
Check the switch setting for Model Select
on the outdoor controller circuit board.