3 Product Description
SMA Solar Technology AG
24
SCCP-JP-BA-A4-en-12
User Manual
3.7.2.3 Soft Grounding
Depending on the order option, the Sunny Central can also monitor for ground faults via Soft Grounding. This process
grounds one terminal of the PV array via a resistor. The PV system must be operated as an electrically closed operation
area.
Figure 8: Soft Grounding in the Sunny Central
If a ground fault occurs on the ungrounded terminal of the PV array, a residual current will occur through the
Soft Grounding resistor. The residual current increases the voltage of the grounded terminal against ground potential.
This enables monitoring of insulation with Soft Grounding using a voltage measurement at the Soft Grounding resistor.
If the measured voltage exceeds a threshold, the PV array grounding is overridden and the residual current is interrupted.
If a Soft Grounding error occurs, the Sunny Central stops operating. A qualified person is required to check and,
if necessary, repair the insulation and reactivate the Sunny Central via the reset button.
It is not possible to detect an insulation error on the grounded pole.
