Upgrading RV system...where to put fuses and/or breakers?

porch13
porch13 Registered Users Posts: 68 ✭✭✭
in Off Grid Solar & Battery Systems #1
Hi everyone,

With the great feedback I've received her, I'm making a few upgrades to my solar setup on my RV. The one thing I'm not sure of is exactly where and what size fuses and/or breakers I need. In the image I attached, I show where I have fuses now. Basically a 25A fuse between my controller and battery bank and an 80A fuse between the battery bank and inverter. I'm assuming the 25A fuse needs to be replaced because I'm moving to the 45A controller. I appreciate any guidance you guys can provide!

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Northern Arizona...4050 Watt off-grid system - Outback FP1 - Rolls 605 in a 48V bank
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #2
    Re: Upgrading RV system...where to put fuses and/or breakers?
    porch13 wrote: »
    Hi everyone,

    With the great feedback I've received her, I'm making a few upgrades to my solar setup on my RV. The one thing I'm not sure of is exactly where and what size fuses and/or breakers I need. In the image I attached, I show where I have fuses now. Basically a 25A fuse between my controller and battery bank and an 80A fuse between the battery bank and inverter. I'm assuming the 25A fuse needs to be replaced because I'm moving to the 45A controller. I appreciate any guidance you guys can provide!
    Although not absolutely necessary, either a fuse or a circuit breaker which will also serve as a disconnect wired between the combined panel + wire and the CC will be handy. Since you have only two panels in parallel it is not necessary to fuse them individually. For three or more panels in parallel, each would need a fuse no larger than the size specified in the panel data.
    SMA SB 3000, old BP panels.
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  • porch13
    porch13 Registered Users Posts: 68 ✭✭✭
    #3
    Re: Upgrading RV system...where to put fuses and/or breakers?

    Since I'll run the panels in Series does that change anything? I like the idea of a breaker on that line because it stinks putting blankets over the panel when I work on anything during the day.
    Northern Arizona...4050 Watt off-grid system - Outback FP1 - Rolls 605 in a 48V bank
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #4
    Re: Upgrading RV system...where to put fuses and/or breakers?
    porch13 wrote: »
    Since I'll run the panels in Series does that change anything? I like the idea of a breaker on that line because it stinks putting blankets over the panel when I work on anything during the day.
    You have got that right. :-)
    Still no fuse or breaker required, but the easiest way to get a disconnect is with a breaker, as fuseholders may not be safe to touch or rated for interrupting DC as you remove the fuse. Also the breaker will protect your panels against a possible fault in the CC.
    SMA SB 3000, old BP panels.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #5
    Re: Upgrading RV system...where to put fuses and/or breakers?

    an alternative is a heavy switch rated for dc.
    here's an example- http://www.solar-electric.com/basw1300amp.html
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  • porch13
    porch13 Registered Users Posts: 68 ✭✭✭
    #6
    Re: Upgrading RV system...where to put fuses and/or breakers?

    That's a cool switch. Since I am adding a second panel with will take me to 425W at about 8A, would I need to replace my current 25A fuse between the controller and the battery with a 60A breaker?
    Northern Arizona...4050 Watt off-grid system - Outback FP1 - Rolls 605 in a 48V bank
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