1 2 3 4 5

IV-3
4. Service procedures
(1)-1 Check before and after Troubleshooting (AER 425 SHLE)
Many problems may happen because of wiring or power supply problems, so you should
check these areas first. Problems here can cause false results in some of the other tests,
and so should be corrected first.
1. Check power supply wiring
❑ Check the power supply wires are correctly connected between terminal
No. 1 & 2 on the 3P terminal plates in the indoor unit and the outdoor unit.
2. Check inter-unit wiring
❑ Check that inter-unit control wiring (DC low voltage) is correctly connected
between the indoor unit and outdoor unit.
RED
WHT
Power Supply: 50 Hz, single-phase, 220-230-240 V
Inter-unit
power wiring
(Line voltage)
Inter-unit
control wiring
(Low voltage)
1
2
1
2
BLK 3 3
Remote controller D
Indoor Unit
1
2
U1
U2
R1
R2
R3
B
C
Ground
Outdoor Unit
Fig. 22
3. Check power supply
❑ Check that voltage is within the specified range (±10% of the rating).
❑ Check that power is being supplied.
If the following troubleshooting must be done with power being supplied,
be careful not to touch any uninsulated live part that can cause ELECTRIC
SHOCK.
4. Check the lead wires and connectors in indoor and outdoor units.
❑ Check that the sheath of lead wires is not damaged.
❑ Check that the lead wires are firmly connected at the terminal plate.
❑ Check that the wiring is correct.
1
2
1
2
4
L
N
A
0
R.C. Address on the PCB: 0 (S2, BLK)
(0: Factory shipped state)
L
N
Ground
Power supply
220 - 240 V 50 Hz
0500_M_I
1
2
3
4
5