Service manual

17
How to check mis-wiring
D
1. Turn OFF the power supply (indoor/ outdoor unit) and disconnect indoor and outdoor
connecting wire at the terminal block 3 of the indoor unit.
2. Short-circuit terminal block N-3 of indoor unit by lead wire.
3. Turn ON the power supply (indoor unit) and press once EMERGENCY OPERATION switch.
During EMERGENCY OPERATION, is there
10V DC between both ends of R601 on the
deicer P.C. board?
(By tester, the stylus is between 5 ~10V.)
As for outdoor unit, refer to service manual OB370.
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 once EMERGENCY OPERATION switch.
Is this mis-wiring, poor contact,
or wire disconnection?
Make them sure.
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.
Yes
No
Replace the deicer P.C. board.
Yes
No
Make the wiring between CN730
on the deicer P.C. board and
outdoor terminal block correct.
Replace the deicer P.C. board.
Yes
Is there 5V DC between J101 + -J401 -
(MU-GA80VB) on the deicer P.C. board?
Yes
Yes
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)
• Disconnect the lead wire that terminal
block N-3 of the indoor unit is
short-circuited.
• Connect ON 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.
MS-GA80VB
OB369-1.qxp 04.10.14 1:37 PM Page 17