All I have the following and would like to know what size circuit breaker and if a fuse is required
Additionally if my wire sizes and mppt are ok
Thanks in advance!
Need to know the Voc and Vmp of the panels. Always provide that detail or a link to the specs.
You can plug that data into the Victron MPPT Calculator to get the right model of solar charge controller.
Between the PV and the solar charge controller you want a dual pole breaker or a PV disconnect switch. Both poles need to be broke at the same time. 15 amp is probably ok, but it depends on the specs of your panels and how you configure them.
For proper sizing, take the expected amps and multiply by 1.25. Round up to the nearest rating of available breakers.
30’ of 10 awg PV cable is probably OK, but you’ll want to configure the panels 2s2p to get the voltage up. Higher voltage allows for smaller cable. I use 10 awg no matter what. Not just because I have gobs of it laying around, but because I want to minimize the voltage drop. The run from the PV to the solar charge controller is the longest run of cable anywhere on my RV (that carries more than a couple amps). The ultimate answer to the awg question is to plug distance, amps and volts into a wire gauge calculator. I use the one on the Bay Marine Supply website. Be aware that it requires a round trip length, not a one-way length. So your 30’ would be entered as 60’.
I prefer a breaker between the solar charge controller and the common busbar. The reason is that it gives me a way to completely isolate (shutdown) the solar charge controller for those times when I need to work on it or other components in the system.
100/30 MPPT would require a 40 amp breaker (30 * 1.25 = 37.5 amps, round up to 40)
100/40 MPPT would require a 50 amp breaker
For this position in a 12 volt system I like to use the Blue Sea 285 Surface Mount breakers.
Jim - wonderful breakdown and thank you for your advise!