Mitsubishi MUH-GA50VB User Manual

31
How to check mis-wiring
D
1. Turn OFF the power supply (indoor/ outdoor unit) and disconnect indoor/outdoor
connecting wire on indoor side.
2. Short-circuit terminal block N-3 by lead wire.
3.
Turn ON the power supply (indoor unit) and press EMERGENCY OPERATION switch once.
During EMERGENCY OPERATION, is there
10V DC between both ends of R601 on the
deicer P.C. board? (Refer to 10-5.)
(By tester, the stylus is between 5 ~10V.)
Refer to indoor unit
service manual.
Start
No
No
Is there 20V DC between both ends of
R132 on the indoor electronic control P.C.
board ?
( By tester, the stylus is between 0 ~ 20V. )
• Turn ON the power supply. (indoor/ outdoor unit)
• Press EMERGENCY OPERATION switch once.
Is this mis-wiring, poor contact,
or wire disconnection?
Correct them.
Replace the indoor electronic
control P.C. board.
Is there 230V AC between L-N
on the outdoor terminal block?
No
Check the outdoor power supply
and connection of wiring.
Is there 5V DC between J205 + -J101 - (MUH-GA50VB)/
J101 + -J401 - (MUH-GA60/GA80VB) on the deicer P.C.
board?(Refer to 10-5.)
Ye s
No
Replace the deicer P.C. board.
Ye s
No
Make the wiring between CN730
on the deicer P.C. board and
outdoor terminal block correct.
(Refer to 10-5.)
Replace the deicer P.C. board.
Ye s
Ye s
Ye s
After 3 minutes, mis-wiring is indicated
(0.5-second ON, 0.5-second OFF)
on OPERATION INDICATOR
lamp on indoor unit.w
w Short circuit of JPG and JPS on the indoor electronic control
P.C. board enables self -check to be displayed in 3 seconds.
• Turn OFF the power supply. (indoor unit)
• Connect indoor/ outdoor connecting
wire.
Turn ON the power supply. (outdoor unit)
When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit doesn’t operate.
After 3 minutes, does the unit
operate in COOL mode?
OK
Yes
Yes
No
Replace the
deicer P.C. board
No
Replace the R.V. coil.
Disconnect the TAB52 on the deicer P.C. board. (MUH-GA60/GA80VB)
Turn ON the power supply and operate the indoor unit in HEAT mode
by pressing the EMERGENCY OPERATION switch.
Is there 230V AC between
CN7211 – 2 (MUH-GA50VB)/
CN7211 – 3 (MUH-GA60/GA80VB)
on the deicer P.C. board?
Check of R.V. coil
C
Unit operates COOL mode even if it is set to HEAT mode.
w First, measure the resistance of R.V. coil to confirm it is disconnected or is not short-circuit.
OB368B-2.qxp 10.5.25 9:16 AM Page 31

Mitsubishi MUH-GA50VB Specifications

General

Brand	Mitsubishi
Model	MUH-GA50VB
Category	Air Conditioner
Language	English