SMA Solar Technology AG
7 Electrical Connection
Operating Manual
MC_BOX_36-BE-en-20
29
13. Connect the neutral conductor to the busbar
MC-X2
(AF 19, torque: 25 Nm). Make sure to
adhere to the following screw assembly:
screw head / terminal of neutral conductor /
terminal lug / fender washer / spring washer / nut.
14. Attach the connection cable to the designated cable support rail. Use the cable clamps and
counter sleeves supplied.
Securing the cable in the support rail relieves the strain on the cable at the connection point.
7.7 Connecting the PV Plant
Cable Dimensioning
Dimension the connection cables adequately for the continuous power of the PV plant and the
short-circuit current of the generator.
In the event of a short circuit, the short-circuit currents released from the generator will flow via the
unprotected connection cable between the Multicluster Box and PV main distribution board. When
planning the short-circuit protection of cables, the PV inverter and Sunny Island inverters may be
disregarded, as their construction precludes any danger to cables in case of short circuits.
Cable requirements:
Conductor material: copper
Maximum conductor cross-section: 300 mm²
Line conductors, neutral conductors and grounding conductors must have the same
cross-section.
Cable protection
The Multicluster Box does not replace the PV main distribution board. Within the PV main
distribution board, you must install circuit breakers to protect and isolate the PV inverters,
and, if necessary, a residual-current device between the Multicluster Box and the PV plant.
Make sure to observe all standards and directives applicable at the installation site.
Connecting other energy generators
Instead of the PV plant, you can also connect other energy generators
(e.g. small wind turbine systems) to the Multicluster Box.
