Answer:

Ground fault circuit interrupters (GFCIs) typically cannot interrupt direct current (DC), which is why they cannot be used in DC power systems. For this reason, all installations must be performed as fixed installations, and touchable parts must be grounded or separated by double or reinforced insulation.

However, an EnergyHub installation can be equipped with a type B GFCI, 300 mA on the AC side for fire protection if prescribed. This assumes that there is no equipment on the DC side that could cause leakage currents leading to false tripping. Ferroamp's SSO and ESO generate negligible leakage currents and can be used in combination with a 300 mA GFCI on the AC side. However, the greater the extent of the DC network and the more devices connected to the DC side, the greater the risk of the GFCI falsely tripping due to normal leakage currents and transients.

Type B GFCIs, 30 mA, can be installed on the AC side of the EnergyHub wall but increase the risk of false tripping in connection with, for example, thunderstorms or transients on the external power grid.

For personal protection, each SSO contains a DC-sensitive GFCI in accordance with EN 62109-2, which disconnects the panels from the DC power network at fault currents above 30 mA.

Type A GFCIs are not recommended in combination with EnergyHub and DC power systems because they are not guaranteed to trip in the event of a ground fault on the DC side.

In cases where multiple EnergyHubs are interconnected on the DC side in a PowerShare installation, GFCIs cannot normally be used because potential equalization currents naturally occur via the different EnergyHubs, which can cause false tripping of the GFCIs.

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