Mitsubishi Electric CITY MULTI PUMY-P200YKM2R2 Technical & Service Manual page 63

Check code
4220
(U9)
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Continued from the previous page.
7,8
Is the outdoor unit
V model or Y model?
Is CN5 connected properly
without any contact failure?
Is there any breakage of ACCT
on the noise filter circuit board?
Check the power supply voltage on the terminal block
of the outdoor unit.
Check the bus voltage read by the microprocessor
with an operation of SW1 on the outdoor multi
controller circuit board.
Is the power supply normal?
Check the bus voltage at the test points
listed below on the outdoor power circuit
board using a multimeter.
V model: CNDC 1-2pin
Y model: N2-P2
Is the bus voltage normal?
OCH675E
Voltage shortage /Overvoltage/PAM error/L1 open phase/
Primary current sensor error/Power synchronization signal error
Diagnosis
6
Y model
Yes
No
Yes
Yes
Yes
The black square (■) indicates a switch position.
Replace the outdoor power circuit board
V model
(Defective outdoor power circuit board).
No
Yes
Replace the noise filter circuit board.
Replace the outdoor power circuit board
(Defective outdoor power circuit board).
Check the power supply facility.
No
The bus voltage can be displayed by an
operation of SW1 on the outdoor multi controller
circuit board.
SW1 Setting
Display on LED1,2
ON
0–9999
OFF
1 2 3 4 5 6 7 8
No Check the power supply facility.
Check the resistor connected to 52C relay
and reactor.
Replace it if the resistor is broken.
No
Replace the outdoor power circuit board if
the resistor is not broken.
Operate the unit and check if the problem
occurs again.
63
Chart 2 of 2
Remedy
Correct the CN5 wiring.
Unit
V