North American HVAC MOC-12HFN1-MS0W, Service Manual

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Troubleshooting
124 Electrical Control System
For 24K~48K Units(excluding MUE-24HRFN1-MW &MTB-24HRFN1-MW)
NO. Malfunction
Defrosting
lamp
Alarm
lamp
Running lamp
Timer
lamp
Display(digital
tube)
1
Communication malfunction between indoor
and outdoor units.
X X X ☆ E1
2
Open or short circuit of T1 temperature
sensor
X X
☆
X E2
3
Open or short circuit of T2 temperature
sensor
X X ☆ X E3
4
Open or short circuit of T2B temperature
sensor
X X ☆ X E4
5 Indoor EEPROM malfunction ☆ X X X E7
6 Indoor fan speed has been out of control ☆ ☆ X X E8
7 Refrigerant leakage detection ☆ ☆ O X EC
8 Outdoor unit malfunction X ◎ X X Ed
9 Water-level alarm malfunction X ☆ X X EE
10
Communication malfunction between main
PCB and up-down panel PCB
☆ ☆ ☆ X F0
11 Up-down panel malfunction
☆ ☆
X
☆
F1
O (on) X(off)
☆
(flash at 5Hz)
◎
(flash at 0.5Hz)
F0,F1 is only available for super-slim cassette
2.3 Outdoor unit malfunction
For MOC-12HFN1-MS0W, MOC-12HFN1-MV0W, MOF-18HFN1-MS0W, MOF-18HFN1-MU0W,
MOG-24HFN1-MT0W:
No. Problems Green Red IU display
1 standby for normal O X
2 Operation normally X O
3 IPM malfunction or IGBT over-strong current protection ☆ X P0
4 Over voltage or too low voltage protection O O P1
5 Inverter compressor drive error X ☆ P4
6 Inverter compressor drive error ☆ O P4
7
Communication malfunction between compressor driver board and
outdoor main board
☆ ☆ P4
8
Compressor driver board EEPROM malfunction
O ☆ E5
O
（
light
）
X
（
off
） ☆（
2.5Hz flash
）