SMA MULTICLUSTER BOX 12 - Manual (Page 11)

SMA Solar Technology AG 4 Product Description
Operating Manual MC-BOX-12-3-20-BE-en-10 11
4 Product Description
4.1 Multicluster Box
The Multicluster Box is an SMA multicluster technology device for off-grid systems, battery-backup systems and systems
for increased self-consumption. The Multicluster Box is a main AC distribution board to which you can connect up to four
clusters. Each three-phase cluster is made up of three DC-side, parallel-switched Sunny Island 6.0H / 8.0H inverters with
software release 3.5 or higher. Functions of the Multicluster Box include:
• Main AC distribution board for Sunny Island inverters, one generator, one load and one PV system
• Load shedding
• Automatic bypass and reverse current monitoring for the generator
• Active anti-islanding
Figure 3: Multicluster Box with cabinet door open
Position Designation Explanation
A Protective cover Prevent inadvertent contact with live components during
operation and thus protect from electric shocks. When the
Multicluster Box is in operation, the protective covers must
always be mounted.
B Protective cover
C Residual-current device Protects against electric shock and is always used in addition to
existing protective measures such as insulation or protective
grounding. As soon as a dangerous touch voltage occurs, the
residual-current device disconnects the loads at all poles.
This is achieved by means of a summation current transformer in
the residual-current device which detects the electric currents in
the conductors L1, L2, L3 and N. In the normal operating state,
the sum of these currents equals zero. Under fault conditions a
differential current is formed which trips the residual-current
device.
D Circuit breakers To protect the power cables of the Sunny Island inverters