MidNite Solar MNPV2-MC4 Pre-Wired Combiner 2 Position with 2 Fuseholders

Everything

This combiner box is designed to join two PV string arrays into one DC feed to the inverter. It's made of quality materials throughout. I used it as a junction box (which may seem like overkill) to transition from the open air MC4 cables used to connect the solar panels to the #8 AWG THHN stranded copper cables going to the inverter. I liked that it had two sets of WC4 connectors on the box that made connecting the panel DC circuits as simple and safe as plugging the panel cables in when all the wiring was in place. I also liked that the box had a 1" knockout for the EMT conduit going from the junction box to the inverter. The larger conduit made pulling the wires a lot easier. I had to modify the combiner box to convert it to a junction box for my purposes. That involved simply removing a steel conductor plate and a lug strip to keep the two DC input circuits separate. The photo shows how I wired the box after those modifications. Note that I left the 15 amp cartridge circuit breakers in the box for extra circuit over current protection.