First ev; nema installation

1/3

I am a first time electric car owner. Just purchased model Y less than week ago. Had and electrician install Nema plug. I used plug Hubbell 14 50R, 9450A; metal 2 gang box and Hubbell cover; the run from main panel was 75 feet; flexible metal conduit under house (raised foundation). I also wanting some sort of box to enclose it to protect it from the sun, gets pretty hot in Southern California and the sun damages everything so I was thinking would be good for longevity.

Electrician used 6 gauge for hots and 8 gauge for neutral and ground. Originally said was using 6 also for neutral but since my panel is wired on neutral bar not the other ground side bar said he had to move to use 8 for neutral. I learned there are adapters to go from 6 to 8 but he ended up using 8 for neutral. I was worried about this but he said was ok and some folks here also said should be ok since the charger doesn’t really use neutral. I really don’t understand that but that’s what I read. My concern is things overheating. But I guess since the hots are 6 gauge hoping it will be ok. I am only charging the Y with official mobile charger which seems to max out at 32 amps. I used a 50 amp breaker.

All of this has been a learning experience and I still feel a bit lost but hopefully all this looks and sounds safe, which is my primary concern. Here are couple pictures of how it turned out and one to see overall placement, towards from of house by driveway. Garage is in the back and like most folks don’t use it as a garage but more long term storage.

Sorry for the long post. I’m like a kid with a new toy.

in evchargingby mario24601

92%

View all comments

e_l_tang

250.122(B) would require the #8 ground since the #6 hots are bigger than needed for a 50A circuit

ematlack

I thought about that when I made my comment. That would only be required if they were upsized due to voltage drop which probably isn’t the reason here. Technically upsizing “just because” doesn’t mean you’d have to bump the ~~OCPD~~ ground (EDIT: oops - misspoke.) The code was changed in the 2011 NEC to make this rule less restrictive.

e_l_tang

The breaker can stay at 50A—I wasn't talking about needing to upsize the breaker. Just the ground wire.

The 2023 NEC says:

If ungrounded conductors are increased in size for any reason other than as required in 310.15(B) or 310.15(C), wire-type equipment grounding conductors, if installed, shall be increased in size proportionately to the increase in circular mil area of the ungrounded conductors.

"Just because" would fall under "any other reason," so you would need the #8 ground here. Unless this was a 60A circuit with #6 hots, which it isn't.

Professional_Buy_615

But the cable was up sized to meet NEC Table 310.15(B)(2)(a)

e_l_tang

You don't know that for sure. And that also doesn't pass the smell test.

If the hots are upsized to #6 for that reason, the neutral needs to be #6 as well, and it's only #8. So based on this your theory cannot be true.

And also, the minimum ground size would be #10, and instead #8 was used. This evidence is not as conclusive as the undersized neutral in disproving your theory but it certainly points in the same direction.

Professional_Buy_615

Doesn't pass the smell test? This installation needed 6g due to temperature derating, it's in CA. This is current rating 101. Yeah, the neutral is undersized, so not to code. However, it will never see 50A charging EVs

e_l_tang

Again, you're acting like you can read the electrician's mind and know for sure that temperature derating was their intention. There are plenty of handymen (who may call themselves electricians) installing 14-50 outlets out there, and temperature derating would never even cross their minds.

What kind of electrician does temperature calculations to upsize the hots but leaves the neutral undersized? And then puts in a ground that's larger than needed?

And the other code violation is the lack of a GFCI breaker, which OP mentioned in a comment on another post.

All of this undermines your assertion that the electrician "knew what he was doing."

Professional_Buy_615

Oh, so he just guessed and randomly hit the correct wire size? It's a good thing we have Reddit experts to check these morons.