Midea MHC-V22W/D2RN8 - L1;L2 Troubleshooting

M thermal Mono
74 202008
Midea M thermal Mono
Service Manual
L1/L2 troubleshooting 4.20.7
The normal DC voltage between terminals P and N on inverter module is 540V. If the voltage is lower than 300V, the unit
displays an L1 error; if the voltage is higher than 830V, the unit displays an L2 error. Refer to Figure4-4.6.
Figure 4-4.6: P, N terminals voltage
V
normal
= 540V DC
Situation 1: L1 or L2 error appears immediately after the outdoor unit is powered-on
L1 / L2
P N +15V wire
on refrigerant system main
PCB is not connected properly
1
Yes
Ensure P N +15V wire is connected
properly
No
Voltage between N and +15 is abnormal
2
Yes
Check +15V circuit
3
No
DC voltage between terminal P and N is
abnormal
Yes
Check power supply, three phase bridge
rectifier
4
No
Replace the main PCB
Notes:
1. P N +15V terminal on refrigerant system main PCB. Refer to Figure4-4.9.
2. Voltage between N and +15. Refer to Figure4-4.7
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