I purchased all the components for my solar about 1.5 months ago. At that time I ordered a few inline 30amp fuses, but unfortunately they haven't arrived yet. I have everything else, so I've been waiting to install, unfortunately I'm leaving in 2 weeks on a 3.5 month trip, so I need to get this done now. I ordered ones like this since I was hoping to have it mostly plug and play. Just connect things together. I was hoping to stay way from splicing wired or adding terminal connectors. In absence of those, what are my options? I can get these inline circuit breakers. Are they appropriate for the places I was going to put fuses? I could splice in fuses like this, but they always seem to be larger gauge wiring than my solar, but maybe I haven't looked carefully enough. Any other recommendations? I'm in Canada, so I have places like Princess Auto, etc to work with. Can't order anything online a this point. Preferably the easier the better. I'm confident I can start making new connections, but its not something I've really done.

I used the fuses like in the last picture. I then used shrink wrap to seal the splices (and covered them from the elements) and they have been working fine ever since.

I have used thisThese are quick and easy if you want to disconnect the panel from the controller. If you want top quality, go with blue seas or bussman.

Just my humble opinion, for a small array like an RV will have, why bother with fuses at all between the panels and controller? They cost you voltage (voltage drop) and introduce more failure points for corrosion. How about a simple disconnect switch, when you need to work on the panels, or the charge controller? The first fuse picture, you shouldn't have to order - Best Buy will have that holder and the fuses for it, it's common for automotive sound installs. I'm surprised Princess doesn't.The middle breaker is complete junk, well, it's handy for things like lights I guess, but I would avoid it. The last fuse is OK, I wouldn't wrap it with anything, that will just trap water in, not keep it out. Put some dielectric grease in there if you want more corrosion protection.

rjxj wrote:I have used thisThese are quick and easy if you want to disconnect the panel from the controller. If you want top quality, go with blue seas or bussman.X2 on this

rjxj wrote:I have used thisThese are quick and easy if you want to disconnect the panel from the controller. If you want top quality, go with blue seas or bussman.Those are what I have on order. Unfortunately they are MIA in shipping and it they don't seem to be available locally. I ordered them a month ago with everything else :(I bought some inline fuse systems today. I think I'll just splice those into the system. Doesn't seem like there are better options.

Breakers for solar | Good Sam Community

19 Replies

Lenny_K
Explorer
Jun 10, 2017
Many charge controllers require you to have circuit breakers installed for the panels and for the battery leads. Can you do without them? Sure you can, but why would you? As stated by other posters I wouldn't let it stop me from a trip if I didn't have them, but I would install them as soon as possible.
Lots of the so called professional installers don't install them which doesn't make it right, but does prove their incompetency.
glennts
Explorer
Jun 10, 2017
After using all of the above and always having thermal issues I went with a pair of Trac digital circuit breakers. Select 30 - 60 Amps, manual or auto reset. More expensive but problem free. Have them set to 30 Amps before the charge controller and 40 Amps after.

https://www.tracoutdoor.com/shop/electrical-items/12v-digital-circuit-breakers-with-display/
time2roll
Nomad
Jun 09, 2017
Also check your alternator output and your starter circuit. Breakaway brake system?

The solar should not overload the wire because the ampacity should be well above the solar rating. Really just protecting the wire from power coming from the battery. Yes if the controller is right there next to the battery IMO skip the fuse is OK. Several feet away or going through blind areas or anything else tricky about it then yes put a fuse close to the battery.

Also don't forget your battery interconnect fuses. One at each end.
mike-s
Explorer
Jun 09, 2017
TechWriter wrote:
time2roll wrote:
You really only need a fuse close to the battery.
And that is not even necessary if the wire is in plain view and not too far from the battery.

Using a wire as a fuse. Great idea :S
Very common with 12V vehicle electronics. It's called a fusible link. Just a short piece of wire of thinner gauge than the rest, so it burns out first in the case of an overload. Although I don't think that's what time2roll meant.
TechWriter
Explorer
Jun 09, 2017
time2roll wrote:
You really only need a fuse close to the battery.
And that is not even necessary if the wire is in plain view and not too far from the battery.

Using a wire as a fuse. Great idea :S
time2roll
Nomad
Jun 09, 2017
You really only need a fuse close to the battery.
And that is not even necessary if the wire is in plain view and not too far from the battery.

You don't need fuses from the panels to controller. The wire should have at least twice the ampacity of the panels and will not even get warm when shorted together.

So cancel your order before they ship.
KD4UPL
Explorer II
Jun 09, 2017
What size fuses are you looking for? For what purpose? If you have only 1 solar panel or 1 string of solar panels in series then there is absolutely no reason to install a fuse between the panel(s) and the controller.
If you have more than 2 panels or strings in parallel then you do need fuses on each string.
Square D QO series breakers are rated for use in DC circuits up to 50 volts. This makes them usable for 12v and 24v solar systems but not 48v since a 48v system will be over 50v when charging. You can get QO breakers and panels at any Lowes, Home Depot, or electrical supply.
Or, you can get purpose made DC breakers. MidNite Solar and Outback both sell them (and some others I'm sure). Most any solar equipment dealer should be able to help.
corvettekent
Explorer
Jun 08, 2017
jpmihalk wrote:
I used the fuses like in the last picture. I then used shrink wrap to seal the splices (and covered them from the elements) and they have been working fine ever since.

X2

Just match the wire gauge and thin install the correct amp fuse.
RJsfishin
Explorer
Jun 08, 2017
Fuses where needed ? Where are they needed ? My installation didn't need any.
But then, if you lack confidence in your installation, then maybe you need them.
2oldman
Explorer II
Jun 08, 2017
GordonThree wrote:
Just my humble opinion, for a small array like an RV will have, why bother with fuses at all between the panels and controller?
x2. Getting fuses in there is not a deal breaker for your trip.