How to Wire a Solar Disconnect for a DIY Camper Electrical System

A solar disconnect is not only convenient but is also a code requirement. By the end of this blog post, you will know what disconnect to use, why you need to use one, and how to size the disconnect.

Links mentioned in this video:

Here are some additional resources that you may find helpful with planning and installing your DIY Camper:

[englishstone]

You explain things perfectly and your speed of talking/explaining is outstanding! I will owe you for a big thanks when I finish my solar project!

[SVInsouciance]

Thank you. Purchased a new SSC and 32A breaker for our boat and subsequently realized that the breaker wiring could be “omni directional”. Now I’m good to go. Nicely done video.

[carykern]

Excellent, I almost purchased 30 amp breakers. Thanks!

[Chris-uteq]

Thank you for citing a standard, in this case the NEC, and explaining why certain things are done in certain ways. Winging it with electrical systems can lead to unexpected/unfortunate outcomes. Standards exist to save lives.

[outthere]

Wonderful! Nigh on perfect. Even I can understand this!!! Really annoying when someone makes a statement but never explains why??? Thankyou for your concise
manner!

[FreeSpiritOz]

I have found your videos just in time.
Im installing solar on my yacht, just as on your camper /RV.
Your videos are very educational. I now can proceed with my installation.
Dont worry I have an electrician friend helping me..

[EminenceFrontX]

Thank goodness this channel exists! Thank you!!!!

[kganatr]

Just started my journey on the campervan trail and I know nothing about electricity and wiring and all this and I apparently said something that surprised my grandpa that is an old naval electrical engineer so I must be learning something. Thanks for the great vids can't wait to learn more. Doing a box truck conversion on an old 1974 dodge 3/4 ton, my very first conversion project! So exciting

[MrA]

You are such an excellent teacher. So step by step logical instructions.

[rikmorel]

Awesome video. I'm building an RV and was just at the stage of adding the solar disconnect. Learned a LOT with this and saved me a lot of hassle down the road, and possibly a disaster as well as I was about to use one of the switches you advised to never use here.

[mallorymcguire]

I love your channel.Ican go back and watch these videos multiple times if I need to, along with all the other ones.

[ARepublicIfYouCanKeepIt]

LOL, that DC-DC charger just wasn't going to let you connect it instead of the MPPT charge controller! Love it.

While the NEC doesn't _technically_ apply to off-grid RV installations, they are, nonetheless best practices. As such, I follow code as much as possible and practical.

This is to say that not everyone does (follow code, that is). I just finished up redoing what what supposed to have been a completed off-grid solar system in a 1969 Airstream renovation. The original work was performed by an electrical engineer. When I got involved, there was one 100V/50A MPPT charge controller for the permanent roof-mount array *and* an auxiliary portable array! A 1-1+2-2 battery switch, rated for 32V max, was installed to connect/disconnect arrays. The 3S 100W panels produced ~65V nominal @ ~6A. This was all connected with 4AWG wire! What a mess.

To correct this, I installed a second, smaller MPPT SCC for the portable PV array. I eliminated the battery selector switch, and installed a non-polarized, dual pole, DC breaker in an enclosure. I did the same between the roof-mount PV array and the first MPPT SCC. I also transitioned the wire down from 4AWG to 10AWG. Not only is the 10AWG more than adequate for the current, but the silicone insulation made cable management so much easier.

A 30A shore power input was also previously installed...with zero protection between it and a MultiPlus worth well over $2K! I installed a non-polarized, dual pole, AC breaker on this line, as well, as one can never be certain what's coming off the post in many campgrounds.

Unbeknownst to me, my client then took the trailer to the largest solar dealer in Atlanta. He paid them $500 to check my work. They assured him that everything was correct. However, they also told him that it was "overkill." What! All I can say is, "Buyer beware."

Someone also told my client that the PV array must be grounded to the trailer chassis. Nothing could be further from correct. One should only ever consider grounding the frames of the PV array. Never the conductors! That's what the PV isolation breaker highlighted in this video is for!

As always, Nate, great work!

[gringosteve]

Such great and straight forward content. For ever subscribed to your channel! Thank you!!

[bhunter]

Thank you for pointing out and explaining the NEC code for this. I'm thinking my combiner box already meets this, but since those are outside I'm going to install a box similar to what you demonstrated with right next to my inverter for convenience. I'm also going to put a label regarding the NEC code on it as a reminder. Your videos are all so clear and purposeful, thank you.

[SocalMarineUSA]

legend bro - setting up solar at my shop cos I dont have a fixed building for city power - your vids are superbly helpful!

[jamescabaniss]

Excellent video. Things are covered that I have asked about and never really got good answers although most you think you know why (it is good to have someone backup your theories, lol).
Some of my thoughts/questions that he answered: why you cannot use the 48 volt DC switches, why you cannot use an AC switch on DC, why you should use 2 wires instead of the usual 1 on a DC switch, etc.

[iamcleverdic]

Thank you. Helped me understand the primary purpose of the circuit breaker: Switch off power from the panels.

[cowboyyoga]

Thanks Teacher!!!! All your videos are super helpful! I am learning slowly but surely! )))

[Psalmist.SamuelAdams]

Got a package from y'all today awesome stuff

[amudlifecrisis]

Nate, I've been watching your videos for a while now. Your video production and associated blogs are of the highest quality and so professional, very impressive. Thanks so much for all the information you share. You have a great teaching style that seems to come so naturally to you. I don't personally build van's or campers but have used your helpful tutorials to build a solar shed and an off grid system for my Ham radio shack/office. 73 de W1SMM