Service manual

20
Check of outdoor unit
D
Compressor and / or outdoor fan motor doesn’t operate.
Yes
Compressor
doesn't operate.
Yes
Yes
Is there 220-240V AC between
3 on the compressor contactor
(52C) and N on the outdoor
terminal block (TB1)?
Operate the unit in COOL or HEAT mode by pressing the
EMERGENCY OPERATION switch.
3-minute time delay works.
Test run operation operates for 30 minutes.
Outdoor fan motor
doesn't operate.
No
Rectify the indoor and
outdoor connecting wire.
Rectify the connecting wire.
Check the compressor and compressor
capacitor, and rectify the connecting wire.
Start
Yes
Is there 220-240V AC between 4
on the compressor contactor (52C) and
TAB20 on the deicer P.C. board?
Is there 220-240V AC between L–N
on the outdoor terminal block (TB1)?
Replace the
deicer P.C. board.
Replace the
deicer P.C. board.
No
No
Yes
Yes
No
Check the outdoor fan motor
and rectify the connecting
wire.
Is there 220-240V AC between 4 on
the compressor contactor (52C) and
TAB 20 on the deicer P.C. board?
Replace the
deicer P.C. board.
No
Yes
Rectify the indoor and
outdoor connecting wire.
Rectify the connecting wire.
Is there 220-240V AC between L–N
on the outdoor terminal block (TB1)?
No
No
Is the switch SW2-2 on the
indoor electronic control
P.C. board set to MUH type?
No
Change the switch SW-2-2
on the indoor electronic control
P.C. board to MUH type.
Yes
+
–
Is there 5V DC between J8 –J9
(MUH-07/09/12RV- , , )/
J205 –J101 (MUH-07/09/12RV- )
on the deicer P.C. board?
+
–
E1
E2
E3
E4
+
–
Is there 5V DC between J8 –J9
(MUH-07/09/12RV- , , )/
J205 –J101 (MUH-07/09/12RV- )
on the deicer P.C. board?
+
–
E1
E2
E3
E4
<MUH-07/09/12RV>
OB252C-1.qxp 02.4.25 11:27 AM Page 20