Check Of Power Supply; Check Of Thermal Fuse; Check Of Rush Current Limiting Circuit; Inverter Does Not Work - Mitsubishi Electric MSZ-G09SV Service Manual

Inverter does not work.

Check of power supply

M
Disconnect the connector
between compressor and
transistor module.
Turn ON power supply to indoor
unit and press EMERGENCY
OPERATION switch.
Three minutes after
power ON, is there
voltage of approx. 230V
AC between outdoor
terminal block 2and N?
Yes
Is there voltage approx.
340V DC between TAB
64(-) and TAB 63(+)?
No
Check the electric
parts in main circuit.

Check of thermal fuse

N
Turn OFF the
power supply.
Outdoor unit does not operate at all or stops immediately due to over current.

Check of rush current limiting circuit

O
When the current limiting resistor is open, the rush current limiting relay may not be working properly.
Therefore confirm the limiting resistor works properly after replacing it.
Start
Repair wiring.
Press the
No
EMERGENCY
OPERATION switch.
Does the 52C work?
Yes
Dose LED light up or
flash?
Is resistance ∞ between the connector CN 201 1 on indoor
electronic control P.C. board and the terminal block N?
Does current limiting resistor (R64) detect 10"?
Ok
Yes
Replace the indoor
No
electronic control
P.C. board.
Replace the outdoor
No
electronic control P.C.
board.
Yes
Ok
No
Ok
No ∞
Yes
81
Outdoor terminal block
N
Indoor/ outdoor
2
connecting
wire
3
Yes
Replace the
thermal fuse (F12).
Indoor electronic
control P.C. board
CN201
Replace the current limiting resistor (R64).