M thermal Mono
202004 97
L1/L2 troubleshooting
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 Figure4-4.9.
Situation 1: L1 or L2 error appears immediately after the outdoor unit is powered-on
P N +15V wire on refrigerant system main
PCB is not connected properly
1
Ensure P N +15V wire is connected
properly
Voltage between N and +15 is abnormal
2
DC voltage between terminal P and N is
abnormal
Check power supply, three phase bridge
rectifier
4
Notes:
1. P N +15V terminal on refrigerant system main PCB. Refer to Figure4-4.9.
2. Voltage between N and +15. Refer to Figure4-4.10
Figure 4-4.9: P, N terminals voltage