Gfdi And Insulation Monitoring Device - SMA SUNNY CENTRAL 500CP XT User Manual

SMA Solar Technology AG
Type of insulation monitoring device used
The insulation monitoring device used is the A-ISOMETER iso-PV1685 device supplied by Bender GmbH & Co. KG.

10.2.3.5 GFDI and Insulation Monitoring Device

With the order option "GFDI and Insulation Monitoring", it is possible to temporarily disable the PV array grounding
and to check the insulation via the integrated insulation monitoring device.
Figure 22: GFDI and insulation monitoring
Position
A
B
When the GFDI is closed, the PV array is grounded. In this state, the insulation resistance cannot be determined.
When the GFDI is open, grounding is disabled. In this state, the insulation monitoring device continuously measures the
insulation resistance. In the operating state "MPP load operation", the insulation resistance of the entire system, from the
PV array to the MV transformer, will be measured. If the inverter is in the operating state "Grid monitoring", only the
insulation resistance from the PV array to the inverter will be measured.
Insulation monitoring should be performed in the operating state "MPP load operation". This will ensure that all parts of
the system are included in the insulation measurement.
Insulation monitoring
The insulation monitoring device will start measuring once the GFDI is open. The insulation monitoring device will
initially assume that the insulation is poor. If the parameter IsoErrIgn is set to Off, the inverter will switch off
temporarily.
The insulation monitoring device takes approximately five minutes to detect the correct insulation resistance. The value
of the insulation resistance can be read off from the user interface in the instantaneous value Riso. If the insulation is
intact, the inverter switches back to the operating state "MPP load operation." Once the insulation monitoring process is
complete, the GFDI should be closed again, thus enabling the PV array to revert to grounded operation.
If after approximately five minutes one of the errors 3501 ‒ Insulation Failure, 3504 ‒ Insulation failure ignored
or 3601 ‒ Warning insulation error is displayed, the insulation is defective. In this case, a qualified person will
need to check and, if necessary, repair the insulation and then acknowledge the error.
Type of insulation monitoring device used
The insulation monitoring device used is the A-ISOMETER iso-PV1685 device supplied by Bender GmbH & Co. KG.
User Manual
Designation
Insulation monitoring device
GFDI
10 Function Description
SCCPXT-E7-BA-en-58 91