35
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 once EMERGENCY OPERATION switch.
During EMERGENCY OPERATION, is there
10V DC between both ends of R601on the
deicer P.C. board? (Refer to page 37or 38.)
(By tester, the stylus is between 5 ~10V)
As for indoor unit,
refer to service
manual OB321.
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.
Is there 5V DC between J205 + -J101 -
(MUH-A18WV)/J101 + -J401 - (MUH-A24/A30
WV) on the deicer P.C. board?(Refer to page
37 or 38.)
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.
(Refer to page 37 or 38.)
Replace the deicer P.C. board.
Yes
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)
• 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.
Unit operates HEAT mode even if it is set to COOL mode.
w
First, measure the resistance of R.V. coil to confirm it is disconnected or is not short-circuit.
After 3 minutes, is there
230V AC between CN721
1
-
3
on the deicer P.C. board?
Replace the
deicer P.C. board.
Yes
No
Replace the R.V. coil.
Disconnect the TAB52 on the deicer P.C. board.
Turn ON the power supply and operate
the indoor unit in COOL mode by pressing
the EMERGENCY OPERATION switch.
Check of R.V. coil
C
OB322-2.qxp 03.11.13 4:08 PM Page 35
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