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Outdoor unit doesn't work.
How to check mis-wiring and serial signal error
E
Make them sure.
1. Turn OFF the power supply
2. Short-circuit between indoor terminal block N and 3.
3. Turn ON the power supply
Is there 5V DC between J8 - –J9 + (MUH-07/09/12RV-
J205 + –J101 - (MUH-07/09/12RV-
Start
Turn OFF the power supply(indoor/outdoor unit).
Is the outdoor unit "MUH or MXZ" type?
•Turn ON the power supply(indoor/outdoor unit).
•Press once EMERGENCY OPERATION switch.
3 min. later, what self-check result is
displayed on OPERATION INDICATOR
w
lamp on indoor unit?
Mis-wiring is indicated.
(0.5-sec. ON, 0.5-sec. OFF)
Yes
Is this mis-wiring, poor contact,
or disconnection of wire?
No
and disconnect indoor and outdoor connecting wire on indoor side.
(indoor/outdoor unit)
and press once EMERGENCY OPERATION switch.
(indoor unit)
Is there 20V DC between both ends of
R132 on indoor electronic control P.C.
board ?
( By tester, the stylus is between 0 ~ 20V. )
•Turn OFF the power supply(indoor unit).
•Connect ON indoor and outdoor connecting wire.
Turn ON the power supply(outdoor unit).
Is the outdoor unit "MUH" type?
Is there 220-240V AC between outdoor
terminal block L-N (TB1)?
E4
Turn ON the power supply(indoor unit).
During EMERGENCY OPERATION,
is there 10V DC between both ends
of R601?
(By tester, the stylus is between 5 ~10V.)
Replace the deicer P.C. board.
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1 Set the switch(SW2-2) on indoor electronic control P.C. board to
MU or MUX type, when the outdoor unit is MU or MUX type.
If the setting is MUH or MXZ type, the unit does not work.
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2 Short circuit of JPG and JPS on the indoor electronic control
P.C. board enables self -check to be displayed in 3 seconds.
No
Yes
Serial signal error is indicated.
(0.5-sec. ON, 2.5-sec. OFF)
2
No
Replace the indoor electronic
control P.C. board.
Yes
No
Refer to "T Check of mis-wiring or mis-piping".
(Refer to page 141 of OB227 REVISED EDITION-B.)
Yes
No
Check the outdoor power supply,
power supply cord and connection.
Yes
,
,
)/
E1
E2
E3
) on the deicer P.C. board?
Yes
Make the wiring between CN730
No
on the deicer P.C. board and
outdoor terminal block correct.
Yes
21
Set the switch(SW2-2) on the indoor electronic
control P.C. board to MU or MUX type.
Does the unit operate?
Refer to the
"Instruction of
troubleshooting."
No
Replace the deicer P.C. board.
w
1
Yes
Ok
No
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