5.3 Installing the DC Main Cables
You can connect up to two DC main cables per terminal by default.
The material required for the bolted connections is already pre-mounted on the busbar; further material is required
depending on the type of connection and cable. Depending on the cable cross-section, the DC main cables must be
connected to the busbars via terminal lugs or V-box terminals:
The following options are available for connecting the DC main cables:
Connecting DC Main Cables to the Busbar Using Terminal Lugs
• DC main cables 70 mm2 to 400 mm2 made of aluminum or copper
– Aluminum cables: additionally required material: bimetal ring terminal lugs.
– Copper cables: tinned copper ring terminal lugs are pre-mounted.
Connecting DC Main Cables to the Busbar Using V-Box Terminals
• DC main cables 70 mm2 to 300 mm2 made of aluminum or copper
Additionally required material: V-box terminals (see Section8, page24).
Connecting the DC Main Cables with Terminal Lugs
Cable requirements for connection with terminal lugs:
☐ Use copper or aluminum cables only.
☐ The cables must be designed for the maximum PV voltage.
☐ Maximum number of cables per potential: 2
☐ Permitted cable cross-section: 70mm2 to 400 mm
2
Terminal lug requirements:
☐ Use tin-plated terminal lugs only.
☐ For the connection, only the supplied screws, washers and nuts must be used.
☐ The terminal lugs must be designed according to the temperature. Temperature: +95°C
☐ The width of the terminal lugs must exceed the washer diameter. Washer diameter: 32mm. This will ensure that
the defined torques are effective over the whole surface.
☐ Maximum width of the terminal lugs when connecting two cables per potential: 48mm
Connecting the DC Main Cables with V-Box Terminals
The DC main cables are connected directly to the busbars with V-box terminals. The V-box terminals are available as
an accessory.
Cable requirements for connection with V box terminals:
☐ Use copper or aluminum cables only.
☐ The cables must be designed for the maximum PV voltage.
☐ The cables must have double or reinforced insulation.
☐ Maximum number of cables per potential: 2
☐ Permitted cable cross-section: 70mm2 to 300 mm
2
☐ Permitted conductor cross-section:
Cable type Conductor cross-section per potential
Round, single-strand 70mm2to150mm
2
Round, multi-strand 70mm2to300mm
2
5 Installation
SMA Solar Technology AG
Technical Information 13SSMUXX1015-TI-en-10