Mounted 6, 250watt SanTan Solar Panels on RV Roof. Have a Question.

[TedH]

On Sunday, a friend helped me mount the 6, 250watt SanTan solar panels on the roof of my RV. I am beginning to connect wires this evening.

My 24vdc power system (up to the common bus bars where DC power flows) consists of the 24v 600ah battery bank, 24vdc 120/240volt 80 amp inverter/charger, 60amp solar charge controller (Aims) and a PV combiner box with four, 20amp breakers). Between the bus bars and the solar charge controller, I have a 250amp on/off switch. I also have an identical on/off switch between the inverter/charger and the bus bars. The two 250amp switches and the PV combiner breakers allow me to isolate the battery bank, inverter/charger, solar charge controller and PV array in event of need for orderly shut down/start up.

My question has to do with use of in-line fuses with the panels on the roof. My six panels will be arrayed in three parallel pairs of two (two panels will be in series). I purchased one 15amp fuse for each panel. Each panel is rated at 8.6amps.

Question: Should I use one 15amp fuse per panel, one fuse per pair of panels OR no fuses at all given I have the Midnight Solar PV combiner box with 20amp breakers for each string/pair (three, 20amp breakers)?

 

[TedH]

For now, I am going to rely on the 20amp breakers that I have in the PV combiner box as fuse/breakers for each string. I won't install the 15amp fuses on roof with each panel. I can always add later if necessary. I also have a 60amp fuse between the bus bars, on/off switch and solar charge controller (the output side of the solar charge controller. PV combiner is the input side).

 

[sunshine_eggo]

My question has to do with use of in-line fuses with the panels on the roof. My six panels will be arrayed in three parallel pairs of two (two panels will be in series). I purchased one 15amp fuse for each panel. Each panel is rated at 8.6amps.

3P or more requires a fuse/breaker per string.

Question: Should I use one 15amp fuse per panel, one fuse per pair of panels OR no fuses at all given I have the Midnight Solar PV combiner box with 20amp breakers for each string/pair (three, 20amp breakers)?

The 20A breakers in the MNPV3 meet the requirement.

 

[TedH]

3P or more requires a fuse/breaker per string.



The 20A breakers in the MNPV3 meet the requirement.

Thanks. I'll leverage the PV combiner box breakers dedicated to each string.

 

[sunshine_eggo]

I wouldn't pry on them with anything. You shouldn't need any leverage.

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