Sparkykc124 t1_ir32s5p wrote on October 4, 2022 at 11:38 PM

Reply to comment by Loon610 in Wiring EV Charger by Loon610

> So no one would frown upon stripping the jacket on the NMD 90 at the start of the conduit and running it like that which would be more flexible

By code, the sheathed cable should enter a box with a connector before being stripped back. Though I’ve seen it done plenty like you’re saying. The other thing to consider is that NM is not listed for use in wet environments and sunlight will degrade the outer sheathing. You want to limit the amount of it that’s exposed to the elements. If it were me, I’d poke the romex through the sill plate, directly into the back of a 6x6 pvc box mounted to the siding, strip it back, roll and tape up the white, and come out of the box with non-metallic liquid tite into the charger. One thing to keep in mind is that it’s almost impossible to keep water out when you put a hole in the top of a box. If you can, come out the side of the box with your liquid tite, or even better, the bottom. Also, drill a couple small holes in the bottom, so when water does get into the box, it can drain out.

> I know bending too tight can cause resistance to increase

The electricity won’t care. Too tight of a bend puts strain on the jacketing and insulation. I don’t think you need to worry about that though, you have to try pretty hard to overbend wire.

Loon610 OP t1_ir3r8sl wrote on October 5, 2022 at 2:50 AM

Thanks a lot for the info this has been very helpful. Just want to run one last thing by you. To clear two things up, the run from the panel to the charger will be up on wall of a garage, through the attic, down the other wall, so I will be going through the top plate not the sill plate. Also the junction box would be inside the garage, I plan on knocking out some drywall and having the junction box exposed to the inside of the garage, then running the conduit from there, so the only thing that should be exposed to the elements is the flexible conduit, the hole it passes though, and the charger what is suppose to be water proof when mounted in the correct orientation. So two questions, no problem going through the attic and down the walls right? Also the NMD being in the attic and on the interior of the garage wall would count as dry interior application, not a wet one right.

The company said 6 gauge is okay to run, and thanks to your advice I think, I will use this as my plan. Either keep the 40amp breaker or possibly upgrade to 50amp, NMD 90 6-3 wire to a junction box in garage wall just on the other side of charger carport location, strip jacket (not insulation)of wire, then from the junction box run wire through flexible non metallic conduit straight into charger through the wall into carport where charger is. What’s your thoughts? Thanks again for the help, you’ve been very informative.

Sparkykc124 t1_ir41s84 wrote on October 5, 2022 at 4:28 AM

Yes, sounds like a good installation. Also, wouldn’t bother changing the breaker.

TiboQc t1_ir3xci6 wrote on October 5, 2022 at 3:44 AM

Not the original commenter nor an electrician, but I did plenty of reading of the requirements here in Quebec before installing my Tesla charger with my electrician father-in-law. From my understanding: attic and wall absolutely count as dry environments, NMD is ok for those. Not sure why you need a junction box before going outside though.
About stripping the neutral wire before going into a conduit, I found this: "installing stripped Romex where the wire may be susceptible to damage is prohibited. This may include installation near sewage lines, bins, garage doors, and even those attached to the face of concrete walls!". Looks like it's ok to strip before going into a conduit, as long as the conduit protects well from environment, from external physical damage (animals, shovels) and is well waterproof (directly connecting to the charger or in a waterproof box).
You could also try to find a 6-2 wire, even better a NMWU so to avoid using a conduit and staying flexible, but those are pretty hard to find.

About the 40amp breaker, I know my Tesla model 3 can only take 32Amp so I kept my 8-3 with 40Amp breaker. Model Ys and some other cars can go a bit higher, but the charger can be configured to stay below 40Amps. If your charger doesn't go beyond 40 or you car use 32amp for example, no need to upgrade the breaker, but it's nice to have it easily upgradable when faster charging becomes available (e.g. your next car).

Anyways, just wanted to participate in the conversation, better have confirmation by a pro. Congrats on your EV, they are so much fun!