Using Fuse in Solar Power Circuit / System

Using Fuse in Solar Power Circuit / System:

Using fuse in solar power circuit or system is must. In the case of solar panels in parallel, a 30-amp fuse is required for each panel.
If your panels are smaller than 50 watts, and use only 12 gauge wires, and 20 amp fuses are required.

Circuit 1:

Solar Panel to Charge Controller Fusing:



# 10 AWG

Use 30A fuse * 4 or 60A fuse * 2

Parallel / Combiner Box Fusing:

# 8 AWG (USE-2) 200 amps or 6 AWG (UF) for 60A charge controller

Charge Controller to Battery Fuse / Breaker:

Use one 60A fuse in positive point...

With 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 size can match. MPPT charge controllers, on the other hand, are able to both lower the voltage and increase the current flowing between the controller and the battery bank, so the exact size wire and fuse size must be recalculated or obtained from the charge controller manual. As an example, Blue Sky recommends a 60-amp fuse/breaker for their Solar Boost 50 (amp) charge controller between the unit and the battery bank. Again, select a wire that is rated appropriately.

Battery Fuse / Breaker to Inverter: