Generator junction box (GJB)

A monitoring system is frequently integrated in the generator junction boxes of central Generator junction box inverter systems. In this case, not only the d.c. side, but also the data technology must be protected. Due to the partial lightning currents to be expected on the d.c. lines, type 1 arresters such as DEHNcombo YPV SCI … (FM) must be installed in the generator junction boxes. This arrester can be used without additional backup fuse up to 1000 A and ensures personal and system protection thanks to its integrated SCI technology. It is recommended to use e.g. BLITZDUCTOR XTU ML2 BD 0-180 to protect the data interface from destruction by lightning strikes and surges.

If systems are fitted with string inverters, most of the cabling is located on the a.c. side. Consequently, it is sufficient to install type 2 arresters on the d.c. side. However, partial lightning currents are to be expected on the a.c. side and therefore it is recommended to install type 1 arresters in the a.c. distribution boards.

d.c. side - Central inverter

Type 1 + Type 2 combined arrester with integrated SCI technology, e.g.

DCB YPV SCI 1000 FM | Part No. 900 067

d.c. side - String inverter

Type 2 arrester with integrated SCI technology, e.g.

DG M YPV SCI 1000 FM | Part No. 952 515

DG YPV SCI 1000 FM | Part No. 950 535

a.c. side

Application-optimised combined arrester, e.g.

DSH TNS 255 | Part No. 941 400

DSH TNC 255 | Part No. 941 300,

DSH TT 255 | Part No. 941 310

Data interface

Space-saving combined arrester, e.g.

BXTU ML4 BD 0-180 | Art.-Nr. 920 349

BXT BAS | Art.-Nr. 920 300