SMA SI 3324 Installation - Manual (Page 33)

SMA Technologie AG Electrical Connection
Installation Guide SI3324/4248-14:SE2406 Page 33
5.1 Grounding
The grounding conductors (DC and AC) must be connected to the connection
terminals labeled as "Grounding" (see figure in section2.2 "At a Glance" (Page 13)).
In stand-alone configurations, the (protective) ground of the Sunny Island
3324/4248 and its individual components must be wired differently
depending on the design of the grid structure. All valid standards and
guidelines must be taken into account!
Only put the Sunny Island 3324/4248 into operation when it has
been properly externally grounded according to the relevant
regulations.
To allow different types of grounding, the N connection of the
Sunny Island 3324/4248 is NOT connected to PE at the factory.
However, since a connection between N and PE is required for
correct operation, this must be done outside of the inverter.
Due to filter measures in the inverter, increased leakage currents
against PE can occur during operation. For this reason, a "fixed
connection" of ground must be implemented according to EN
50178. Ground the inverter with a copper conductor (at least 10
mm² cross-section), or with two separate copper conductors with a
cross-section of at least 4 mm² each.
External grounding of the negative pole of the batteries is possible, because
the batteries and the grid side are galvanically isolated within the Sunny Island
3324/4248. In this case, make sure that the high currents that may occur under
fault conditions can be adequately diverted.