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Wall charger installation question
- Thread starter tkt546
- Start date
dgbehrends
Member
I want to eventually power share mine which made me put the extra effort into getting a 60amp circuit. I figured if I'm going to be charging two cars on the same circuit I want to get the maximum current possible out of it. Running two 50 amp circuits would have cost more and probably flipped my main if I happened to run my air-conditioner and dryer at the same time. 4awg nm-b is super expensive ~$12 a foot if you can find it even sold by the foot. I had a 50ft+ run of wire to front of my garage. I settled on 6awg MC solid coper $5 a foot sold at my local graybar store. My electrician didn't see the benefit of getting that extra 8amps and had always just done $50 amp circuits on his many installs so he wasn't sure about where to get the 6awg MC as most homes don't need that type of circuit. After some research I got the wire for him and he did the install. A tough run from my basement into the garage attic and then down the front of the garage but it came out nicely with all 5 green bars lighting up on my gen 3. Total for the install was about $1200 which includes the gen3 as well.
sleepydoc
Well-Known Member
i.e. he's trying to figure out a way to get out of fixing his mistake once you pointed out the code to him!
You consider 100' a short run? I could be wrong, but you would be buying 6 AWG THHN per wire, by the foot. It's not like Romex where it's 6/2, 6/3. Copper wire is crazy expensive now. In CA, 6 AWG THHN is over $1.50 per foot. If you have a 100' run, that's two hots at $1.50 per foot and then 100' ground wire, that doesn't necessarily need to be 6 AWG. Still, just for two hot wires at 100', that's $300 alone.
You could do all that, or buy a $10 50amp breaker and be done with it.
Ok got it. If you used a licensed electrician and he used Romex for a 60 amp circuit, he should re-do the wiring with THHN for free, or at least just the difference in cost between the Romex and THHN. He shouldn’t charge you for the labor.
That’s the reason for using a licensed/insured electrician. If they make a mistake, they should make it right on their dime since you’re paying them to do it right.
I did use one it's just most still don't know the difference as proved by multiple threads.
Hey I liked the kid and I'm not a dick honestly romex would be fine even for 48 amps in my install. It's still thhn in Romex it's just some bs rule to account for every situation.
You’re too nice, if you’re a licensed electrician you should know the difference between NM Romex and THHN and when/where Romex can be used. If you hired a handyman I’d be more understanding.
I had a 50 amp circuit installed last week for a wall charger by an electrician. I researched prior to getting it installed and after 30 mins of Googling even I learned that you can’t use NM Romex for a 60 amp circuit. After looking at the estimate from the electrician I went with, I saw he had 8 AWG THHN, not Romex for a 50 amp circuit. Even though Romex would have been acceptable for the 50 amp circuit, I feel safer having the THHN separated.
You wouldn’t be a dick if you asked him to fix his mistake. It’s ok, we all make mistakes and you can be nice and still be adamant he fix his error.
It's still early I'm waiting for him to do the right thing.
sleepydoc
Well-Known Member
I agree - that’s why you hire a licensed electrician and that’s their job. LIke @Kairide said, you don’t have to be a jerk about it. Hopefully he comes back and fixes his mistake without you having to push further.
How is the cable run? Is it in the wall, in conduit or just stapled to the wall? A lot of NM cable is actually THHN encased in the PVC sheath so he may be Able to salvage the wires, depending.
I agree I see a ton of setups on here done the same way. I don't think electricians have caught up with EV requirements. They're still using the upsize rule with the 55amp Romex.
It's just secured to the concrete blocks. And yeah mine is THHN in the PVC. Which is the funny part logically exposed Romex sitting on cool cinderblocks should be able to dissipate more heat then the same THHN in a hot enclosed conduit. I still want it done to code just saying In my opinion I don't think this setup poses any fire risk vs a MC or conduit THHN 6-2. If this were an in wall in attic garage install I would say that it's risky.
sleepydoc
Well-Known Member
My understanding of the rationale is that the PVC has a lower melting Point than the nylon and it also serves prevent heat insulation. If you have THHN in MC the metal conduit more effectively dissipates the heat. Note that there are fill requirements/limits on EMC, it’s not like THHN gets a ‘free pass,’ either.
I’d also note that code doesn’t allow for bare NM cable on walls ‘where susceptible to damage.’ That’s a bit vague and dependent on your inspector. My inspector said it had to be in conduit even though it was up by the ceiling.
Yeah I do like the idea of it being in MC though it comes out of the top of my panel so it's at least 6' in the air up and over the garage door and down to the middle. MC can get crushed though and you don't know the state of the wire inside.My understanding of the rationale is that the PVC has a lower melting Point than the nylon and it also serves prevent heat insulation. If you have THHN in MC the metal conduit more effectively dissipates the heat. Note that there are fill requirements/limits on EMC, it’s not like THHN gets a ‘free pass,’ either.
I’d also note that code doesn’t allow for bare NM cable on walls ‘where susceptible to damage.’ That’s a bit vague and dependent on your inspector. My inspector said it had to be in conduit even though it was up by the ceiling.
dgbehrends
Member
That should work and is the same spot I had my gen 3 installed. If I ever get another electic car I will just daisy chain another gen 3 and power share off the same 60amp circuit. I used 6/3 MC in case I ever wanted to install a 14-50 outlet and paid the same price for 60 ft of it. You should be able to get 48amps out of that charger. My installer put the wire on the inside of the wall so it doesn't show.
sleepydoc
Well-Known Member
If an electrician does the install you won't be able to do that - NEC requires that each EV charging circuit be separate. You can have a sub panel with two brach circuits off of it for each EV, though.
That would have previously been the case, now each Gen3 Wall Connector would need to be on it's own circuit breaker. This could involve separate wire runs from the service panel or from a sub panel. You can use the Tesla automatic load sharing when more than one Gen3 Wall Connector is installed. With a 60 amp breaker and a sub panel a single Gen3 Wall Connector could charge at 48A. Two Gen3 Wall Connectors could charge at the same time, 24A each or set up so that the total charging amperage does not exceed 48A, i.e. 32A and 16A.
Now:
Circuit: (60A breaker)===WC-A (Charges at 48A)
Future:
............Sub Panel (60A breaker)=
..............................................................|| (60A breaker)==WC-A (Charges at 48A/24A if both WC are in use at the same time)
..............................................................|| (60A breaker)==WC-B (Charges at 48A/24A if both WC are in use at the same time)
dgbehrends
Member
Ok Just so I understand this correctly. I can't just tie two gen 3 wall chargers to the same 60amp circuit even though they would never both use more than 48amp combined. Why is this??
So what you are saying I need to do is run a subpanel off of my existing 60amp breaker and in that sub panel have a 60amp breaker for each of the Wall chargers. Knowing that I currently have 6/3 MC run about 55ft from my main panel to the garage wall. What would be the optimal placement for the subpanel? On the garage wall so the run to each gen3 is short?
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