Check code
4220
(U9)
Voltage shortage/overvoltage/PAM error/L1open phase/primary
current sensor error/power synchronization signal error
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Diagnosis
Remedy
The black square (■) indicates a switch position.
Chart 2 of 2
Replace the outdoor power circuit board
(Defective outdoor power circuit board).
Yes
No
No
Yes
Yes
No
Yes
Yes
No
No
Yes
7,8
6
Y model
V model
Is CN5 connected properly
without any contact failure?
The bus voltage can be displayed by an
operation of SW1 on the outdoor multi
controller circuit board.
Correct the CN5 wiring.
Continued from the previous page
Is there any breakage of ACCT
on the noise filter circuit board?
Is the power supply normal?
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.
Replace the noise filter circuit board.
Replace the outdoor power circuit board
(Defective outdoor power circuit board).
• Decrease of power supply voltage
• L1 open-phase
Replace the outdoor power circuit board
(Defective outdoor power circuit board).
Replace the outdoor power circuit board
(Trouble of an input current detection
circuit is suspected).
Check the power supply facility
(Check if a receiving electricity is lowered).
Check the bus voltage read by the microprocessor
with an operation of SW1 on the outdoor multi
controller circuit board.
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
ON
OFF
1 2 3 4 5 6 7 8
SW1 Setting
Display on LED1,2
Unit
0–999.9
V
Is the outdoor unit
V model or Y model?
69
OCH668B
