Electrical Connection
SMA Solar Technology AG
24
WB33-38-IA-IEN120940
Installation Manual
Load disconnect unit
You must install a separate miniature circuit-breaker for each inverter in order to ensure that the
inverter can be securely disconnected under load. The maximum permissible fuse protection can be
found in Section 11 "Technical Data" (page 69).
Detailed information and examples on the design of miniature circuit-breakers are available in the
Technical Information "Miniature circuit-breakers" to be found in the download area of
SMA Solar Technology AG at www.SMA.de/en.
DANGER!
Danger to life by fire.
When more than 1 inverter is connected in parallel to the same miniature circuit-breaker,
the protective function of the miniature circuit-breaker is no longer guaranteed. It can result
in a cable fire or destruction of the inverter.
• Never connect several inverters to the same miniature circuit-breaker.
• Observe the maximum permissible fuse protection of the inverter when selecting the
miniature circuit-breaker.
DANGER!
Danger to life by fire.
When a generator (inverter) and a load are connected to the same miniature circuit-
breaker, the protective function of the miniature circuit-breaker is no longer guaranteed.
The currents from the inverter and the grid can accumulate to form overcurrents that are not
detected by the miniature circuit-breaker.
• Never connect the load between the
inverter and the miniature circuit-breaker
without protection.
• Always protect the load separately.
NOTICE!
Damage to the inverter due to use of screw-type fuses as load disconnection units
A screw-type fuse, e.g. DIAZED fuse or NEOZED fuse, is not a switch-disconnector and thus
may not be used as a load disconnection unit. A screw-type fuse only acts as cable
protection.
Disconnection under load using a screw-type fuse may damage the inverter.
• Use only a switch-disconnector or a miniature circuit-breaker as a load disconnection
unit.