IP68 Split-Type PV Junction Box

The PV module junction box houses the bypass diodes that protect module cells from hot-spot damage during partial shading. When cells in a series string are partially shaded, they are driven into reverse bias by the current flowing through the unshaded cells — a bypass diode conducts this reverse current around the shaded cell group, preventing the shaded cells from acting as resistive loads that generate destructive localised heat within the module laminate.

OmniSol's IP68 fully potted junction box uses Schottky barrier diodes for their lower forward voltage drop (approximately 0.3V versus 0.6–0.7V for standard p-n diodes), which reduces power dissipation in the diode during bypass events and lowers steady-state junction temperature. Full UV-stable resin potting eliminates the O-ring seal compression failure mode that affects non-potted designs after repeated thermal cycling in outdoor environments.

Junction box current rating must match the module Isc plus a design margin for reverse current in parallel-string configurations. A 15A rated box is standard for most 60 and 72-cell modules with Isc up to 12A; 20A and 30A options cover high-current bifacial modules and DC-coupled storage configurations. Specify the module Isc and system architecture when ordering to confirm the correct diode and contact rating for the application.