Huawei SUN2000 Series User Manual page 91

SUN2000-(12KTL-25KTL)-M5 Series
User Manual
Figure D-2 Percentage of short-circuit positions
Procedure
If the irradiance or the PV string voltage is too high, the insulation resistance fault
location may fail. In this case, the fault location status on the Alarm details
screen is Conditions not met.Perform the following steps to connect PV strings to
the inverter one by one to locate the fault. If the system is not configured with
any optimizer, skip the corresponding optimizer operations.
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 DC SWITCH to OFF.
Step 2 Connect one PV string to the inverter, and set DC SWITCH to ON. If the inverter
status is Shutdown: Command,log in to the app, choose Maintenance > Inverter
ON/OFF on the home screen, and send a startup command.
Step 3 Connect one PV string to the inverter, and set DC SWITCH to ON. If the inverter
status is,log in to the app, choose Maintenance > Inverter ON/OFF on the home
screen, and send a startup command.
Issue 01 (2022-06-15)
NO TE
● The positive and negative terminals of a PV string are respectively connected to the PV+
and PV– terminals of the inverter. The PV– terminal represents a possibility of 0% for the
short-circuit position and the PV+ terminal represents a possibility of 100% for the
short-circuit position. Other percentages indicate that the fault occurs on a PV module
or cable in the PV string.
● Possible fault position = Total number of PV modules in a PV string x Percentage of
possible short-circuit positions. For example, if a PV string consists of 14 PV modules
and the percentage of the possible short-circuit position is 34%, the possible fault
position is 4.76 (14 x 34%), indicating that the fault is located near PV module 4,
including the previous and the next PV modules and the cables. The inverter has a
detection precision of ±1 PV module.
● The possible faulty PV string MPPT1 corresponds to PV1 and PV2, and the possible
faulty PV string MPPT2 corresponds to PV3 and PV4. The fault can be located only to
the MPPT level. Perform the following steps to connect the PV strings corresponding to
the faulty MPPT to the inverter one by one to further locate and rectify the fault.
● When a non-short-circuit fault occurs, the possible short-circuit percentage is not
displayed. If the insulation resistance is greater than 0.001 MΩ, the fault is not related
to short circuit. Check all PV modules in the faulty PV string one by one to locate and
rectify the fault.
NO TICE
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D Locating Insulation Resistance Faults
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