String Box BIG

Connection technology PV generator junction box string box BIG large plants megawatt range



Stringbox BIG


  • individually exchangeable
  • Plastic or steel housing possible
  • from standard to high-end everything available


Areas of application
Large plants in the megawatt range, open field plants and large roof-top plants (e.g. factory buildings).

Basic construction

The BIG string box is a generator connection box for large systems. There are 5 standard versions with 8, 12, 16, 20 and 24 inputs. All the usual modules for large systems such as DC isolators, surge protection, PV fuses and current sensors can be integrated here. The Stringbox BIG is usually planned and constructed according to customer specifications. No wishes remain unfulfilled here.

String box BIG with 8-16 strings remote triggerable DC isolator sensors fuses in positive and negative pole
String box BIG in plastic casing, 16 strings 15 A, fuses in positive pole Current measurement i'checker 4, bundled strings. ÜSS T2, telecommunication contact, ÜSS 24 VDC bus, DC disconnector 315 A/1 kV
PV connection system generator junction box string box

Technical Data String Box BIG


Number of strings8 to 24
I max. per string30 A
U max. per string1 kV
Contacting M12/M16/M20/M25 (your choice)
Plug cable cross-section1 to 25 mm²


Number of outputs1
I max. per string800 A
U max. per string1 kV
Contacting M40/M50/M63/M75 (your choice)
Plug cable cross-section95 bis 300 mm²


HousingSheet steel housing, IP55, optionally with fan/heater


DC circuit breaker
Overvoltage protection T1+T2/T2
String current measurement
Voltage measurement
Data transmission via RS485
Data transmission via LoRa/GSM (wireless)

Our portfolio in the field of connection technology, string boxes, generator connection boxes

String Box Simple

extremely low construction, up to 5 inputs

String Box Easy

extremely compact, up to 18 inputs


String box with galvanically separated printed circuit boards

String Box BIG

Generator junction box for large plants/parks

AC Sub-distribution

customer-specific variant with OVP T1+T2

Special Boxes

cost-optimised - benefit-optimised