SMA GRID CONNECT BOX 12 - Manual (Page 7)

SMA Solar Technology AG 2 Safety
Operating Manual GRID-BOX-12-3-20-BE-en-10 7
2 Safety
2.1 Intended Use
The Grid Connect Box is an automatic transfer switch which enables the safe operation of the utility grid and a generator
as energy sources of an SMA Multicluster System.
Figure 1: Circuitry principle of the multicluster system with the Grid Connect Box
The technical connection requirements of the grid operator and the local standards and directives specify if the
multicluster system, in the event of grid failure, disconnects from the utility grid at all poles or only the line conductors.
The Grid Connect Box is always delivered with all-pole disconnection. If all-pole disconnection is not permitted, this
configuration of the Grid Connect Box must be deactivated (see Section 6.2, page 18).
If the Grid Connect Box is used with all-pole disconnection, the utility grid must be configured as a TN-S, TN-C-S or TT
system. If the Grid Connect Box is used without all-pole disconnection, the utility grid must be configured as a TN-C-S
system (for grounding in the multicluster system see operating manual of the Multicluster Box).
Do not exceed the maximum AC connection power of the Grid Connect Box. Cables with copper wires must be used for
the installation.
BATFUSE
SUNNY ISLAND
GRID-BOX
Load contactor
MULTICLUSTER BOX
(Main AC distribution board)
PV main
distribution box
(not included in the
delivery)
BATTERY
Generator contactor GENERATOR
LOAD
PV MODULES
PV inverters
UTILITY
GRID