SMA SC 500HE-US - Manual (Page 24)

3 Product Description SMA America, LLC
24 SC500HEUS-eng-BE-BUS120320 Operating Manual
3.7 Insulation Monitoring Via GFDI
The insulation monitoring in the Sunny Central is performed via Ground Fault Detection Interruption
(GFDI).
GFDI is performed via a high-performance k-type miniature circuit-breaker with adjustable operating
current. The miniature circuit-breaker is integrated in the inverter and connected between a positively
or negatively grounded input busbar and the grounding busbar.
Figure 7: GFDI in the Sunny Central
3.8 Grid Management
3.8.1 Requirements
PV plants must participate in feed-in management in accordance with IEEE 1547. Most importantly
the grid operator must be able to limit the power of the PV plant by remote control and temporarily
reduce it to zero in critical cases. The relevant control commands of the grid operator must therefore
be transmitted to the Sunny Central quickly and reliably for implementation.
The following figure shows how the specifications of the grid operator are implemented. The
Power Reducer Box sends the specifications of the grid operator to the inverters.