Decentralised junction box for PV applications

Compared with centralised junction boxes commonly used in the PV industry, the decentralised box is said to require 50 per cent less jumper cable to connect to the next solar panel, as the junction boxes are located in the corner of the panels.

The decentralised junction box uses fewer cross-connects than standard centralised boxes, offers good thermal management capabilities and enables engineers to design innovative solar panel layouts.

The general design idea is using two small two-rail junction boxes separately located in the corners of the solar panels, plus one small junction box in the middle (compared with the common standard layout of one bigger four-rail junction box with three diodes in the centre of the panel).

Through the decentralisation of the two-rail junction boxes, panel manufacturers are able to use fewer and shorter cross-connects - saving labour and costs - because every string is protected by one junction box with one diode.

With this design concept, Tyco Electronics said it is easy to enlarge solar panel layouts by adding a junction box in the centre to protect additional strings; no complicated routing is required.

The low-profile design (only 18.5mm height) of the two-rail decentralised junction box enables the device to be easily terminated with the slim-line connector system.

The decentralised junction box meets IEC 61215 ed.2 (VDE V 0126-5) specifications.