What is a combiner box? - solarpowerworldonline Jun 30, 2015The role of the combiner box is to bring the output of several solar strings together. Daniel Sherwood, director of product management at SolarBOS, explained that each string conductor lands on a fuse terminal and the output of the fused inputs are combined onto a single conductor that connects the box to the inverter.Author: Joshua Smalley how-properly-fuse-solar-pv-system - Web - windynation Parallel/Combiner Box fusing. In a parallel system a combiner box is used that holds the fuses/breakers to each panel, plus one or more “combined” fuse leading to the charge controller or grid tie inverter (see figure). When sizing this “combined” fuse/breaker, we must first determine the worst case current that will flow based on ourParallel/Combiner Box FusingIn a parallel system a combiner box is used that holds the fuses/breakers to each panel, plus one or more “combined” fuse leading to the charge con..Charge Controller to Battery Fuse/BreakerWith a Pulse Width Modulated (PWN) charge controller, the worst-case amps flowing to and from the controller are the same, so the fuse and wire siz..Battery Fuse/Breaker to InverterThe wiring and fusing from the battery to an AC/DC inverter is of critical importance because this is where the most current will likely flow. Simi..