Mitsubishi Electric PUMY-P200YKM2 Technical & Service Manual page 59

Check code
4220
(U9)
Abnormal points and detection methods
If any of following symptoms are detected;
●Decrease of DC bus voltage to 400V
●Increase of DC bus voltage to 760V
●DC bus voltage stays at 310V or less for consecutive 30 seconds when
the operational frequency is over 20 Hz.
●When any of following conditions is satisfied while the detections value
of primary current is 0.1A or less.
1. The operational frequency is 40Hz or more.
2. The compressor current is 6A or more.
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Is there any abnormality on wirings?
7,8
Which sub code is displayed?
Does DC bus voltage raise to
approx. 350 V at PAM driving?
Is there any abnormality on
PAM wirings?
Is there any abnormality at the
PAM circuit on the outdoor power
circuit board?*
Is there any abnormality at
the PAM power supply circuit or
52C relay drive signal circuit on
the outdoor multi controller?*
*Refer to "8-7. HOW TO CHECK THE PARTS".
Continue to the next page.
OCH675D
Undervoltage/Overvoltage/PAM error/L1 open-phase/
Primary current sensor error/Power synchronization signal error
Diagnosis
No
3
No
vzv
No
No
No
Causes and checkpoints
Decrease/increase of power supply voltage
2 Primary current sensor failure
Disconnection of compressor wiring
Malfunction of 52C
Disconnection or contact failure of CN52C
Defective outdoor power circuit board
Malfunction of 52C driving circuit on outdoor multi
controller circuit board
Disconnection of CN5
Disconnection of CN2
0 Malfunction of primary current detecting circuit on
outdoor power circuit board
The black square (■) indicates a switch position.
a. Disconnection of compressor wiring
Yes
b. Disconnection of CN52C
c. Disconnection of CN5
d. Disconnection of CN2
The sub codes are The sub codes are
displayed by an operation displayed by an operation
of SW1 on the outdoor of SW1 on the outdoor
6
controller board. controller board.
SW1 Setting
Display on LED1,2
1 2 3 4 5 6 7 8
ON
OFF
1 2 3 4 5 6 7 8
Yes
Yes
Replace the outdoor power circuit board
Yes
(Defective outdoor power board).
Replace the outdoor multi controller
circuit board.Breakage of wiring for PAM
Yes
controlling power supply, and such.
Replace the outdoor power circuit board
(Defective outdoor power circuit board)
59
Remedy
3: PAM error 3: PAM error
6: Input sensor trouble 6: Input sensor trouble
7: Shortage voltage trouble 7: Shortage voltage trouble
8: Overvoltage trouble 8: Overvoltage trouble
Check the power supply facility.
Correct the wiring.
Chart 1 of 2