● Connect the possible faulty optimizer to the PV string.
● Set DC SWITCH to ON. If the inverter status is Shutdown: Command, choose
Maintenance > Inverter ON/OFF, and send a startup command. View alarm
information.
– If no Low insulation resistance alarm is reported 1 minute after the DC
side is powered on, the fault is on the possible faulty PV module.
– If the Low insulation resistance alarm is reported 1 minute after the DC
side is powered on, the fault is on the possible faulty optimizer.
● Log in to the app, choose Maintenance > Inverter ON/OFF on the home
screen, and send a shutdown command. Set DC SWITCH to OFF, replace the
faulty component, and complete troubleshooting the insulation resistance
fault. Go to Step 2 and check rest of the PV strings one by one. Then, go to
Step 8.
Step 8 Set DC SWITCH to ON. If the inverter status is Shutdown: Command, choose
Maintenance > Inverter ON/OFF, and send a startup command.
----End
SUN2000-(12KTL-25KTL)-M5 Series
User Manual D Locating Insulation Resistance Faults
Issue 03 (2023-02-15) Copyright © Huawei Digital Power Technologies Co., Ltd. 103