Mitsubishi Electric MUZ-FH25VEHZ Service Manual page 38

J Check of power supply
Disconnect the connector between the
compressor and the power module
(IC700) (MUZ-FH25/35)/IGBT module
(IC700) (MUZ-FH50).
Turn ON power supply and press
EMERGENCY OPERATION switch.
Does POWER lamp on the indoor
unit light up?
Yes
Is there bus-bar voltage 260 - 370
VDC between DB61 (+) and DB61 (–)
(MUZ-FH25/35)/325 - 370 VDC
between JP715 (+) and JP30 (–)
(MUZ-FH50) on the inverter P.C.
board? (Refer to 11-6.1.)
No
Check the electric parts in main circuit.
OBH625A
Rectify indoor/outdoor
connecting wire.
Yes
Is there voltage 230 VAC
between the indoor terminal
No
block S1 and S2?
Does LED on the inverter P.C.
board light up or fl ash?
Yes
(Refer to 11-6.1.)
Yes
If light up, OK.
If fl ash, refer to 11-3.
325 -370 VDC
38
Replace the indoor
electronic control P.C.
No
board.
Replace the inverter
No
P.C. board.
260 - 370 VDC
DB61
Inverter P.C. board
(Solder side)
MUZ-FH25/35
JP30
JP715
MUZ-FH50