FollowMitch
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Many variables here, not sure if I should fuse the 6 AWG wire between the combiner box and the charge controller.
See attached diagram
See attached diagram
To fuse or Not to fuse 6 AWG wire
- Thread starter FollowMitch
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Hedges
I See Electromagnetic Fields!
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- Mar 28, 2020
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With wire ampacity > 1.56x 2x Isc(of a panel), I don't see a need to fuse it.
Two strings in parallel, don't need fuses either.
A disconnect is handy. You can get a breaker, e.g. from Midnight, suitably rated. I prefer non-polarized; they have some in panel-mount. But since this goes to a charge controller and presumably can never be driven with reverse-current by it, polarized should be OK too. They have DIN rail breakers which are polarized.
Two strings in parallel, don't need fuses either.
A disconnect is handy. You can get a breaker, e.g. from Midnight, suitably rated. I prefer non-polarized; they have some in panel-mount. But since this goes to a charge controller and presumably can never be driven with reverse-current by it, polarized should be OK too. They have DIN rail breakers which are polarized.
FollowMitch
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Thanks "Hedges" I do plant to insert a disconnect switch. now time to get going
Maast
Compulsive Tinkerer
If you're subject to NEC 2017 they require a disconnect, but it can also be a fuse or breaker that you can open.
FollowMitch
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Jim Burrow
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6 AWG wire in my opinion is overkill but very safe. Your panels are putting at most 10 amps with two in series. I'm just using 12 AWG as it can handle 20 amps or more. For me, I have 3 parallel banks of panels made up of 2 panels in series. 6 panels total. Each parallel branch puts out 9 amps and the series voltage is 78 volts. (not what I've been getting in real life). So with 3 parallel branches, they are putting out a max of 27 amps. So my branches are using 12 AWG and where they all connect together, I'm using 10 AWG. major overkill, but better say than sorry.
I do have on/off switches for each panel string. For convenience to me for maintenance. I do not have a circuit breaker between my controller and solar panels coming into the controller. But the breakers are check and I should add one just for safety. Although I've been testing my system for over 6 months without solar breakers. Won't be installing my system until April.
Anyway, hopefully, this gives you some ideas and answers some of your concerns. I had them too when I first started with my system.
Note, if your solar panels are really, really far from your controller, then you might concede the heaver wire like you are using. My panels setting in my yard is connected to my controller using 50-foot extension cords. I have no issures.
I do have on/off switches for each panel string. For convenience to me for maintenance. I do not have a circuit breaker between my controller and solar panels coming into the controller. But the breakers are check and I should add one just for safety. Although I've been testing my system for over 6 months without solar breakers. Won't be installing my system until April.
Anyway, hopefully, this gives you some ideas and answers some of your concerns. I had them too when I first started with my system.
Note, if your solar panels are really, really far from your controller, then you might concede the heaver wire like you are using. My panels setting in my yard is connected to my controller using 50-foot extension cords. I have no issures.
