Mitsubishi Electric CITY MULTI, Техническое и сервисное руководство

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