Mitsubishi Electric PUMY-P112VKM3 Technical & Service Manual page 72

Check code
Voltage shortage/overvoltage/PAM error/L1open phase/primary
4220
(U9)
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Continued from the previous page
7,8
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 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 tester.
V model: CNDC 1-2pin
Y model: N2-P2
Is the bus voltage normal?
The difference of the voltage between the
one read by the LED1 and 2, and the one at
the test points listed above is large.
OCH632A
current sensor error/power synchronization signal error
Diagnosis
6
Is the outdoor unit
Y model
Yes
No
Yes
Yes
Yes
No
The black square (■) indicates a switch position.
Replace the outdoor power circuit board
V model
(Defective outdoor power circuit board).
No
Replace the noise filter circuit board.
Yes
Replace the outdoor power circuit board
(Defective outdoor power circuit board).
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
0–999.9
OFF
1 2 3 4 5 6 7 8
• Decrease of power supply voltage
No
• L1 open-phase
Replace the outdoor power circuit board
No
(Defective outdoor power circuit board).
Replace the outdoor power circuit board
Yes
(Trouble of an input current detection
circuit is suspected).
Check the power supply facility
(Check if a receiving electricity is lowered).
72
Chart 2 of 2
Remedy
Correct the CN5 wiring.
Unit
V