SMA SI 3324 Installation - Manual (Page 37)

SMA Technologie AG Electrical Connection
Installation Guide SI3324/4248-14:SE2406 Page 37
5.2.2 Cable Protection
In addition to the DC circuit breakers within the Sunny Island 3324/4248, install a
separate load disconnecting switch as close as possible to your batteries. Install a
suitable fuse plug for the load disconnecting switch according to the maximum
specified DC current (e.g NH1 at 200 A for the SI4248 and NH1 at 250 A for the
SI3324).
If you do not wish to use the system for an extended period of time, then
always disconnect the battery cables from the inverter.
The Sunny Island 3324/4248 does not connect either the positive or the
negative DC pole to ground. If a connection is required, then this must be
made by an installer.
If no cable protection (load disconnecting switch) exists, then the
DC cables must be protected against ground faults and short
circuits. The internal DC fuse of the Sunny Island 3324/4248 is
designed such that it can interrupt currents of up to 10 kA.
For short circuit currents greater than 10,000 A an additional
thermal fuse is absolutely essential ("SI-BattCase.01-200" for the
SI4248 or "SI-BattCase.01-250" for the SI3324).