Yeah considering you mentioned 8 wires that would be a fair amount of bulk. There is no problem with using outdoor rated items indoors however the reverse is not true.
Butt splice connectors to extend INDOOR PV wire....Why not?
- Thread starter energyhunter
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energyhunter
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energyhunter
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Exactly, thx MattB4
DougfromdaUP
Solar Enthusiast
Wire nuts are the cheapest, and among the lowest resistance- way better than WAGO or MC4.
They are also easy to install and don’t require a torque measuring device.
Why don’t you like them?
They are also easy to install and don’t require a torque measuring device.
Why don’t you like them?
energyhunter
New Member
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I don't dislike them...I've used plenty over the years for lights and plugs. I've found so many that were no longer 'tight.' I always tape them too. Technically I understand your point, but I see no arc risk with a hydraulically crimped and marine sealed butt-splice, yet I do not feel the same level of confidence with good-ole' dependable wire nuts. Saving a couple bucks is not on the table for me with this level of risk. I'll bet you that no one ever found a loose wire nut that you installed and I do value your comment, thank you DougfromdaUP.
Checkthisout
Solar Wizard
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How is it anymore risky than the other 9 billion connections made with wire nuts?
For any damp or wet locations, no wire nuts and no split bolts UNLESS you will be permanently potting them with electric safe epoxy. In which case they cannot be serviced in the future.
Other splice methods that use double wall thickness heat shrink with waterproof adhesive are effective as well as epoxy potting kits. But once you heat shrink or epoxy, no servicing the connection except to cut it off.
I have decided to only use the NSI Polaris waterproof submersible EPDM rubber covered wire connectors. Yes, they cost more, but they are easy to install, contain a silicone conducting anti-corrosion gel, and can be easily removed and used again if wires need replacement or upgrading.
Other splice methods that use double wall thickness heat shrink with waterproof adhesive are effective as well as epoxy potting kits. But once you heat shrink or epoxy, no servicing the connection except to cut it off.
I have decided to only use the NSI Polaris waterproof submersible EPDM rubber covered wire connectors. Yes, they cost more, but they are easy to install, contain a silicone conducting anti-corrosion gel, and can be easily removed and used again if wires need replacement or upgrading.
Quattrohead
Solar Wizard
When I attach wire nuts they are so tight that they are never coming undone and absolutely do not need electrical tape wrapped around them, that is so amateur. After doing 100 or so my arm cramps up so bad I can't even hold a beer 
ScrotpusGobbleBottom
Corn Pop was a bad dude.
Why?
All metal should be grounded yes? Dc PV lines will short to the box and not trip any breakers. Why is that optimal? How is that any different than a direct short on pv lines?
Quattrohead
Solar Wizard
That's what NEC requires, I'm just the messenger.
ksmithaz1
Solar / EV Junkie
Arc. Metal will not catch fire from the arc.
Sounds like a professional technique. Can you explain a little how it gets done the right way for me?When I attach wire nuts they are so tight that they are never coming undone and absolutely do not need electrical tape wrapped around them, that is so amateur. After doing 100 or so my arm cramps up so bad I can't even hold a beer
From your panels to a combiner box you should be using PV rated wire. This wire is rated to be in the air and weather and is also rated to have UV resistant sun protection. From the combiner box/disconnect switches you can use THHN/THWN/MTW which is cheaper and meant to be in conduit. Outdoors you can run PVC conduit and boxes. Indoors of any structure your DC current wires must be in metallic conduit per code. This can be EMT or flexible aluminum. The boxes also must be metallic. If not metallic, a ground wire must pass through them so anything metallic is properly grounded like an outlet in a pvc wall box. The metallic boxes must be grounded which in turn will carry the ground via the metallic conduit to all other metallic boxes and even the inverter and battery enclosure if metallic. If running a ground from your disconnect switch into a structure, this is a ground from a DC source. therefore it can be separated from an AC ground source like a utility grid tied panel. So it would terminate in a grounding rod close to the batteries and inverter. If the inverter is not grid tied, then it needs to be connected to a grounding rod along with batteries and the array. If the inverter is grid tied, then the inverter can be grounded to the AC ground supplied by the grid tied source.
I bet very few do it this way
Well, its the right way. PV wire is rated to be in the open air from the panels to the combiner box or other enclosure. It is UV resistant. As such, it costs more per foot than THHN/THWN/MTW which are not rated for UV exposure. As for fusing and breakers and disconnect and lightening arrestor and grounding, those are all good practices to meet codes and for longevity.
I do agree with you
I think the main take away forum users should be getting by reading posts and receiving advice and help here is to remember that the primary goal of having a PV system is to build it and then forget about it. If you keep having to service it, tweak it, make repairs, redo connections, add more panels and arrays, make new trenches and connections, etc it just becomes a labor of hate rather than the completion of an enjoyable useful project.
Get it done, but build it one way, the right way using best practices and professional technique.
And please, forget wooden mounts. Just get some 2 inch schedule 40 galvanized pipe, it cuts like butter with portable band saws, lasts forever and provides the strength and rigidity that panels need to avoid a mount that doesn't contract and expand with the weather.
Get it done, but build it one way, the right way using best practices and professional technique.
And please, forget wooden mounts. Just get some 2 inch schedule 40 galvanized pipe, it cuts like butter with portable band saws, lasts forever and provides the strength and rigidity that panels need to avoid a mount that doesn't contract and expand with the weather.
For some of us we enjoy tweaking it, changing things around, adding more panels, creating new arrays and just trying things out. Good practices and proper connecting is always a good idea.
Nothing wrong with a wood mount. It may not be a forever method but it works and for some of us that is sufficient.
So I would say what a Forum reader should take away is understand the science and enjoy the process. We all don't have the same end goal in mind.
