SMA SC 400HE - Manual (Page 61)

SMA Solar Technology AG 5 Insulation Monitoring
Operating Manual SC4-63HE-BE-BEN103280 61
5.3 Combining GFDI and Insulation Monitoring Device
The insulation monitoring device with GFDI does not provide protection from injury. By combining the
GFDI and insulation monitoring device options, you can manually switch the PV array from grounded
operation to insulated operation. To ensure that there is no insulation error on the grounded pole, an
insulation measurement is carried out. After switching to insulated operation, the insulation monitoring
device checks each pole of the PV array for potential insulation errors.
Switching to insulated operation, for example, is required for any maintenance or service work on or
near the PV array such as cutting the grass.
Switching from Grounded to Insulated Operation
1. Turn the key switch on the inverter to "Stop".
2. Wait 5 minutes.
3. Open the inverter.
4. Manually switch off the GFDI miniature circuit-breaker.
5. Close the inverter.
6. Turn the key switch on the inverter to "Start".
☑ The insulation monitoring device starts collecting data. Normally a ground fault will be
reported first. The error message disappears once the insulation monitoring device detects
the correct insulation resistance after approx. 5 minutes.
Switching from Insulated to Grounded Operation
1. Turn the key switch on the inverter to "Stop".
2. Wait 5 minutes.
3. Open the inverter.
4. Manually switch on the GFDI miniature circuit-breaker.
5. Close the inverter.
6. Turn the key switch on the inverter to "Start".
☑ The inverter starts to work in grounded operation.