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The breaker panel is on the outside wall of my garage, right opposite the spot I want to hardwire an electric vehicle charger (EVSE). The charger would be in the garage.

My plan is to drill a hole in the wall and wire the cable through one of those pop out covers in my panel. The cable would never be exposed outside of the garage drywall. Is there any code requirements for how much clearance is needed from the panel and where I drill the hole? I wasn't sure based on what I was searching.

The plan is to use a 60A breaker and a 4/3 Romex cable, which I believe should be fine?

Here is a pictures of the panel. Right opposite the panel is the garage.

panel

Click to enlarge

Edit:

Example picture of the Tesla wall connector with I believe #4 awg cable that I saw on YouTube.

enter image description here

Also, note I've been using a 120v outlet for my charging needs for 3 years already for my Model Y. I know I do not need the 60A circuit, but I'm now in a new house and due to the simplicity of the install (which I might be fully wrong about) of the panel being right on the opposite side of my garage wall, I decided to just go to the max. So I don't think there's really much price difference in a 40, 50, or 60A circuit for me. Since in my head I'd only need less than 5 feet cable. I don't actually plan to even charge the full 48A most of the time.

Also note that I have a 200A panel.

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  • You mean use (for example) the knockout to the right of the one with the large red and black wires? I don't see why you couldn't. Obviously you'd want to remove the knockout and drill from the box side of the wall (protect the black & white wires against the drill) to ensure your hole in the other side of the wall lines up. Hopefully there's no stud there. Is the box mounted to a plywood panel on the wall? Assuming no wires cross behind that knockout, of course...
    – Huesmann
    Jul 11, 2023 at 12:55
  • @Huesmann, yeah I'd be using that knockout. Yeah, the panel box is mounted to a plywood panel. Is that an issue?
    – Dmoles
    Jul 11, 2023 at 15:32
  • What car will you be charging? Can it really use the 60A (48A continuous)?
    – Rodo
    Jul 11, 2023 at 17:57
  • It can, it's a model Y. Note that I've been using a 120v outlet for my charging needs for 3 years already. I know I do not need the 60A circuit, but due to the simplicity of the install (pleas correct me if I'm wrong) of the panel being right on the opposite side of my garage wall, I decided to just go to the max. So I don't think there's really much price difference in a 40, 50, or 60A circuit for me.
    – Dmoles
    Jul 11, 2023 at 18:18
  • @Dmoles no, the plywood isn't an issue. Just a function of "stuff you need to drill through." Harper has you covered in his answer.
    – Huesmann
    Jul 12, 2023 at 12:27

1 Answer 1

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Rethink 60A

Let's start with a common misconception: EV novices get fixated on the Fastest Charge Possible. 60A is bonkers overkill for daily home charging needs. It's even a little heavy for travel (i.e. when you arrive after a day's travel at a hotel and need full by morning). Yes, level 1 is inadequate, but eight times faster is overkill - three times faster suffices for most people, and that's only 20A/240V.

As the video I link says, it's unnecessarily expensive, and may come with more headaches than you bargained for. Off the top of my head:

  • Must do a NEC Article 220 Load Calculation on the loads now on the service to assure that your service can handle this huge additional load safely.
  • Must pull a permit for such a large circuit (some AHJs waive permits for simple 15-20A circuits including 240V circuits).
  • Must notify your power company about such a large load.
  • 60A circuits require #4 Romex (#6 will not suffice, despite what you may have heard) or #6 THHN which requires conduit.
  • Some EVSEs can't accept #4 wire.
  • It's harder on the EV battery.

And that Load Calculation is going to be extra important, since I see a lot of heavy feeders heading up the left side gutter.

Straight out the back will suffice

You may notice two conduits already punch through the wall. You can either add to those (provided length is <24" and fill is <60%) or punch another conduit through and have it land on a box on the other side. If you align the holes, you don't need fittings even; you can use a threaded conduit nipple about 1" longer than the back-to-back distance of the panel/box interiors, and put conduit nuts on the accessible side. (note this is not good enough for grounding; you'll need a ground wire).

If it's practicable to run conduit all the way to the EVSE I recommend this. 3/4" conduit will suffice for any wire size you're likely to want. Even 1/2" conduit will get you to 65A. In that case you build the conduit complete before pulling any wires in. This requires proper construction, including access points at sharp corners.

If you prefer to come out of the side and then go through the wall, you can do that either in cable (SEU or NM or UF) or conduit. The cable will need some sort of physical protection where it might be vulnerable to damage; conduit works fine for that, and in that case you do not need to follow the "build complete before filling" rule. Note the following ampacity limits:

  • #12 copper anything: 20A
  • #10 copper anything: 30A
  • #8 copper NM or UF cable: 40A
  • #8 copper "anything else" or #6 aluminum: 50A
  • #6 copper NM or UF cable: 55A
  • #6 copper "anything else" or #4 aluminum: 65A
  • #4 copper NM or UF: 70A

The cable ampacity and breaker must be 125% of the actual charge rate; your EVSE installation manual usually accounts for this.

If that exact size of breaker is not available, you use the next larger size, but you are not allowed to use those amps. This results in a very common error of using #6 Romex for a 60A-breakered EVSE. No, that is 5A over its capacity and you must re-commission the EVSE for the 50A setting (since none have a 55A setting).

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  • Must notify your power company about such a large load. Really? If you are within the provisioned service based on a proper, updated, load calculation, why would you need to notify the power company? (Unless there are local rules about that.) Jul 11, 2023 at 18:02
  • Thanks for the detailed response. I'll respond to the other points late on, but regarding the need of the 60A circuit. I've been using a 120v outlet for my charging needs for 3 years already for my Model Y. I know I do not need the 60A circuit, but due to the simplicity of the install (please correct me if I'm wrong, and I may be based on your response) of the panel being right on the opposite side of my garage wall, I decided to just go to the max. So I don't think there's really much price difference in a 40, 50, or 60A circuit for me. Since in my head I'd only need less than 5 feet cable
    – Dmoles
    Jul 11, 2023 at 18:22
  • The plan is to use the Tesla wall connector which can accept #4 AWG cable as well. I also have a 200A panel by the way.
    – Dmoles
    Jul 11, 2023 at 18:22
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    @Dmoles everyone thinks that lol. But then they get smacked with unexpected headches. Starting with the Load Calc. (and don't bother with the story of how you plan to be careful; that falls apart when another human gets involved: guest, the person who buys your home, etc.) Agreed, if you're gonna run the wire, run 60A wire for such a short distance, but when commissioning pick a sensible value that corresponds to the Load Calc, power company convo, permit requirements etc. Jul 11, 2023 at 18:25
  • If I use the conduit nipple, I could then use #6 THHN then right? Because I was planning on Romex because I saw that you're allowed to run it through the wall without conduit in the garage. And I think I definitely prefer to just come out the back of the panel to the EVSE in the garage.
    – Dmoles
    Jul 11, 2023 at 18:42

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