Mitsubishi Electric Mr. Slim PUZ-M200YKA2.UK Service Manual page 33

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 "10-9. 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 than
04 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 more is
08
detected on power circuit board.
PFC error (Overvoltage/
Undervoltage/Overcurrent)
PFC detected any of the follow-
ing:
a) Increase of DC bus voltage to
10 420 V.
b) Decrease in PFC control volt-
age to 12 VDC 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 310 V or
20
lower for consecutive 10 seconds
OCH775B
Cause
Abnormal increase in power source
voltage
Disconnection of compressor wiring
Defective outdoor power circuit board
Compressor has a ground fault.
Decrease in power source voltage,
instantaneous stop.
Defective 52C drive circuit in outdoor
power circuit board
Disconnection or loose connection of
rush current protect resistor RS
Defective rush current protect resistor
RS
L1-phase open
Disconnection or loose connection
between TB1 and outdoor noise filter
circuit board
Disconnection or loose connection
of CN5 on the outdoor power circuit
board/CNCT on the outdoor noise filter
board
Defective ACCT (AC current trans)
on the outdoor noise filter circuit
board
Defective input current detection
circuit in outdoor power circuit board
Defective outdoor controller circuit
board
Distortion of power source voltage,
noise superimposition.
Disconnection or loose connection of
earth wiring
Disconnection or loose connection
of CN2 on the outdoor power circuit
board/controller circuit board
Defective power synchronous signal
circuit in outdoor controller circuit
board
Defective power synchronous signal
circuit in outdoor power circuit board
Not applicable for M200/250Y model.
Not applicable for M200/250Y model.
33
Judgment and action
Check the field facility for the power
supply.
Correct the wiring (U . V . W phase) to
compressor. Refer to "10-8. TEST POINT
DIAGRAM" (Outdoor power circuit board).
Replace outdoor power circuit board.
Check compressor for electrical insula-
tion. Replace compressor.
Check the field facility for the power
supply.
Replace outdoor power circuit board.
Check RS wiring.
Replace RS.
Check the field facility for the power supply.
Check the wiring between TB1 and out-
door noise filter circuit board.
Check CN5/CNCT wiring.
Replace outdoor noise filter circuit board.
Replace outdoor power circuit board.
Replace outdoor controller circuit board.
Check the field facility for the power supply.
Check earth wiring.
Check CN2 wiring.
Replace outdoor controller circuit board.
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.