Mitsubishi MSH-30RV - How to Check Mis-Wiring and Serial Signal Error

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How to check mis-wiring and serial signal error
G
Yes
Yes
1. Turn OFF the power supply.
2. Turn ON the power supply.
3. Press the EMERGENCY OPERATION switch.
3 min. later, when 52C contactor turns ON, what self-check result is
displayed on OPERATION INDICATOR lamp on the indoor unit? ❈1
Start
1. Turn OFF the power supply and disconnect in-out connecting wire on the indoor side.
2. Short-circuit between indoor terminal block and .
3. Turn ON the power supply and press the EMERGENCY OPERATION switch.
3
N
1. Turn OFF the power supply.
2. Re-connect in-out connecting wire.
3. Turn ON the power supply.
3 minutes later, when the EMERGENCY OPERATION switch is
pressed and 52C contactor turns ON, is there 220-240V AC between
the outdoor terminal block - ? ❈2
N
2
Is there 5V DC between J8 -J9 (MSH-18RV)/
J101 -J401 (MSH-24RV) on the deicer P.C.
board? Refer to page 69 or 70. ❈2
Is there 10V DC between both ends of R601 on the
deicer P.C. board? Refer to page 69 or 70. ❈2
(By tester, the stylus is between 5 ~10V)
Replace the deicer P.C. board.
Rectify in-out connecting wire.
Check and rectify the fuse and the varistor
on the outdoor deicer P.C. board.
Rectify in-out connecting wire.
Replace the indoor electronic control
P.C. board.
❈1 Short circuit of JPG and JPS on the
indoor electronic control P.C. board
enables self-check to be displayed in 3
seconds.
Serial signal error is indicated.
(0.5-sec.ON, 2.5-sec.OFF)
Repair wiring.
Is there mis-wiring, poor contact, or wire disconnection?
Is there 20V DC between both ends of R132 when
52C contactor turns ON?
( By tester, the stylus is between 0 ~ 20V. )
–
Yes
Yes
No
No
No
No
No
Yes
Mis-wiring is indicated.(0.5-sec.ON, 0.5-sec.OFF)
❈2 While the serial signal error is indicated,
52C contactor alternates ON for about 10
seconds and OFF for 3 minutes.
Measure the voltage when 52C contactor
is ON.
Outdoor unit doesn’t operate.
<MSH-18/24RV>
+
–
+
When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second or flashes once.
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