4 connecting the utility grid – SMA MULTICLUSTER BOX 12 User Manual
Page 20
6 Electrical Connection
SMA Solar Technology AG
20
MC-BOX-12-3-20-BE-en-10
Operating Manual
3. Connect the neutral conductor to the spring-cage terminal N at terminal X102:4 (see Section 9.4.1, page 34).
4. Connect the line conductors to the spring-cage terminals L1, L2 and L3 at terminal X102:1-3.
5. Ensure that a right-hand rotating magnetic field is present at the generator terminal.
6. Provide for strain relief of the power cables by attaching them to the appropriate cable support rail. Use the strain
reliefs and counter-troughs provided.
7. 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 Generator.
6.4 Connecting the Utility Grid
To connect the utility grid in addition to the generator, it is necessary to install either a Grid Connect Box or an NA Box
between the utility grid and the Multicluster Box.
Requirements:
☐ If using Grid Connect Box: The Grid Connect Box must be properly installed (see operating manual of the Grid
Connect Box).
☐ If using NA Box: The NA Box must be properly installed (see operating manual of the NA Box).
Cable requirements:
☐ Conductor material: copper
☐ Conductor cross-section: 120 mm² to 150 mm²
☐ The power cables must be ground-fault and short-circuit protected.
Procedure:
1. Insert the power cables into the Multicluster Box (see Section 9.3.1, page 31).
2. Connect the grounding conductor to the grounding busbar
(AF 17, torque: 15 Nm). To do this, use the screw terminal
included in the scope of delivery.
3. Connect the neutral conductor to the spring-cage terminal N at terminal X101:4 (see Section 9.4.1, page 34).
4. Connect the line conductors to the spring-cage terminals L1, L2 and L3 at terminal X101:1-3.
5. Ensure that a right-hand rotating magnetic field is present at the terminal of the Grid Connect Box / NA Box.
6. Provide for strain relief of the power cables by attaching them to the appropriate cable support rail. Use the strain
reliefs and counter-troughs provided.
The grid terminal output fuse influences dimensioning of the PV system power cables
Remember that the size of the grid fuse affects the dimensioning of the PV system cable (see Section 6.6 "Connecting