Sunny Island 4500
Installation & Operating Instructions
BWRI45-13-EE0304
- 53 -
SMA Regelsysteme GmbH
3.4.7 Connection to an External Utility
Such a plant option requires a very careful design and installation in
order to prevent accidents based on the assumption that the plant is
deenergized as it is disconnected from the utility!
In several operating modes energy feeding into the external utility is
possible via the Sunny Island!
The illustrated interconnection plans show the grid connection only in
principle.
In any case, the local applicable regulations have to be
complied with and the approval of the public utility company is man-
datory!
If the public mains supply often fails, an island utility can be desirable. In this case the
Sunny Island will normally charge the battery during supplementary grid feeding from
the external utility. In case of mains failure the plant must be disconnected from the
external utility and the Sunny Island must provide the 230 V island grid in grid-
forming operation. After the external utility has recovered, the Sunny Island needs to
detect this voltage and the switch-over to island operation mode has to be reversed.
The necessary wiring is shown in Fig. 3.12. The voltage sensor cables that also have
to be connected with the voltage measurement input port “Generator / Mains sync
input” – just like in the case of the connection of a generator (see Chapter 3.4.5 and
Chapter 3.4.6) – are not shown.
