Huawei SUN2000-250KTL Series User Manual page 91

SUN2000-(250KTL, 280KTL, 300KTL, 330KTL) Series
User Manual
Step 1 Ensure that the AC connections are normal. Log in to the FusionSolar app, choose
Maintenance > Inverter ON/OFF on the home screen, and send a shutdown
command. Set the DC SWITCH of the SUN2000 to OFF.
Step 2 Connect a PV string to the SUN2000 and set the DC SWITCH to ON. If the
SUN2000 status is Shutdown: Command, choose Maintenance > Inverter
ON/OFF on the home screen and send a startup command.
Step 3 Choose Alarm on the home screen, enter the Active alarm screen, and check
whether a Low insulation resistance alarm is reported.
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Step 4 Choose Maintenance > Inverter ON/OFF on the home screen and send a
shutdown command. Set the DC SWITCH to OFF. Check whether the connectors
or DC power cables between the possibly faulty PV modules and adjacent PV
modules are damaged.
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Step 5 Disconnect the possibly faulty PV module from the PV string, and use a DC
extension cable with MC4 connectors to connect the adjacent PV modules. Set the
DC SWITCH to ON. If the SUN2000 status is Shutdown: Command, choose
Maintenance > Inverter ON/OFF on the home screen and send a startup
command. View alarm information.
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Issue 07 (2023-06-30)
If no Low insulation resistance alarm is reported 1 minute after the DC side
is powered on, choose Maintenance > Inverter ON/OFF on the home screen
and send a shutdown command. Set the DC SWITCH to OFF. Go to
and check the other PV strings one by one.
If a Low insulation resistance alarm is reported 1 minute after the DC side is
powered on, check the percentage of possible short-circuit positions on the
Alarm details screen and calculate the location of the possibly faulty PV
module based on the percentage. Then go to
If yes, replace the damaged connectors or DC power cables and then set the
DC SWITCH to ON. If the SUN2000 status is Shutdown: Command, choose
Maintenance > Inverter ON/OFF on the home screen 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 insulation resistance fault location of the PV
string is complete. Choose Maintenance > Inverter ON/OFF on the
home screen and send a shutdown command. Set the DC SWITCH to
OFF. Go to Step 2
Step 7.
– If the Low insulation resistance alarm is still reported 1 minute after the
the DC side is powered on, choose Maintenance > Inverter ON/OFF on
the home screen and send a shutdown command. Set the DC SWITCH to
OFF and go to Step
If no, go to Step 5.
If no Low insulation resistance alarm is reported 1 minute after the DC side
is powered on, the fault occurred on the disconnected PV module. Choose
Maintenance > Inverter ON/OFF on the home screen, send a shutdown
command, and set the DC SWITCH to OFF. Go to
If the Low insulation resistance alarm is still reported 1 minute after the DC
side is powered on, the fault did not occur on the disconnected PV module.
Go to Step 6.
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and check the other PV strings one by one. Then, go to
5.
8 System Maintenance
Step 4.
Step 7.
Step 2
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