SMA Solar Technology AG
Danger to life due to fire
In case of a short circuit, the short-circuit currents from the external energy source flow through the
unprotected cables between the off-grid inverter and the AC sub-distribution.
• If the fuse of the external energy source is rated higher than the fuse in the AC sub-distribution,
dimension the cable to match the fuse of the external energy source.
• The cable to the AC sub-distribution should be dimensioned at least to match the feed-in
capacity as. You do not need to take the AC sources in the stand-alone grid or the off-grid
inverters into account when considering cable protection, as their design inherently prevents
them from damaging the cables if a short circuit occurs.
Connecting off-grid inverters in single-phase parallel single-cluster systems:
Figure 13: Correct, symmetric connection and incorrect, asymmetric connection of off-grid inverters
Installation Manual
6 Electrical Connection
SI80H-60H-OffGrid-IA-en-11
41