6 Electrical Connection
SMA Solar Technology AG
Operating manual
MC-BOX-6-3-BE-en-30
19
3. Connect the line conductor to the fuse switch-disconnector
F2 Loads
as labeled.
4. According to the type of cable routing and the installation conditions, determine the required
fuse link for the fuse switch-disconnector and insert it into the fuse switch-disconnector.
6.4
Connecting the PV System
Cable protection
The Multicluster-Box does not take the place of the distribution board of the PV system (PV
main distribution board).
• Install a circuit breaker and, if necessary, a residual-current device between the
Multicluster-Box and the PV system for protection and disconnection purposes.
• Adhere to all standards and directives for the installation of electrical devices and systems
applicable at the installation location.
Connection of other energy sources
Instead of a PV system, you can connect other energy sources (e.g., small wind turbine
systems) to the Multicluster-Box.
Cable dimensioning:
In the event of a short circuit, short-circuit currents caused by the generator will flow through the
unprotected power cable between Multicluster-Box and PV main distribution. If the generator fuse is
larger than the fuse in the PV main distribution board, the power cables must be dimensioned to
match the generator fuse.
The PV inverters and Sunny Island do not need to be considered when planning line protection in
case of a short circuit, as they are designed to not to pose any danger to power cables during a
short circuit. Overload protection is guaranteed if the power cables to the PV system are at least
dimensioned for the feed-in power of the PV system.
Cable requirement:
☐ Conductor type: copper wire
☐ Maximum connectable conductor cross-section: 35 mm²
Procedure:
1. Insert the power cables into the Multicluster-Box (see Section 9.1, page 24).
2. Connect the grounding conductor and the neutral conductor to the terminal
X3 PV-System
as
labeled.
3. Connect the line conductor to the fuse switch-disconnector
X3 PV-System
as labeled.
6.5
Connecting the Sunny Island
Fusing of the Sunny Island inverters
The power cables of each Sunny Island inverter are fused with a 40 A circuit breaker inside
the Multicluster-Box.