Wiring for Tesla Wall Connector on outside garage wall

[antio]

Hello,

I'm planning to install the Wall Connector outside my garage. It's an unfinished garage, so just studs & plywood on the inside, and vinyl siding & a sheet of insulation on the outside.

My circuit breaker panel is right next to the garage door, and I'll put the WC either right next to that (but outside), or on the other side of the garage door. So my wire run will be either about 5 feet or about 18 feet.

I've run a similar circuit before when I put in the 240V line for my mini-split A/C unit, but that's a much lower current device.

From reading other threads here, and the WC manual, I see I need a non-GFCI 60A breaker.

And I should use #6 wire for 48A charging (80% continuous load on the 60A circuit).

I plan to use one of the rear entry ports on the WC wirebox.

Question #1: I assume I cannot use 6/2 romex for this, since romex is not for use outdoors? Even though, with rear entry, it wouldn't *exactly* be running outdoors, except for the portion that's inside the WC...

So that means using THWN wire, then.

Question #2: THWN must be run inside a conduit, right?

Question #3: I've read that I can use #10 wire for the ground even while using #6 for the two load lines; is that accurate?

Question #4: What's the best kind of bushing/fitting to secure the conduit to the rear of the WC, given that it'll be sort of half inside the wall?

Final question: My circuit breaker panel currently has all the circuits coming in through the bottom, but there *are* knockouts on the top of it. Is there any reason I can't use the top ones?

Thanks for any advice.

 

[ElectricIAC]

We used 3AWG for our recent HPWC install but it’s set up for 80A output.

 

[Sophias_dad]

1) #6 is not big enough if it's Romex/NMB cable for 48 amps continuous, you'd need #4. You aren't allowed to use NMB there anyway, but not because of the few inches outside. Its because of the garage itself, being considered a 'damp or wet' location. It would also be rather unpleasant to use NMB because it has to be protected from physical damage like fire or your handy fire axe falling against it. That leaves you with #6 THWN in conduit, which IS allowed to carry 48 amps continuously.

2) yes, THWN should be in conduit (THWN is the 'wet' qualified THHN, but pretty much all THHN is also THWN)

3) #10 ground is fine with #6 conductors. Its actually what is in the bundle if you get #6 NMB.

4) There are conduit fittings similar to the wire clamps you are probably used to with NMB. I don't believe there's a requirement for actually clamping the conductors, but the conduit must be captured by the clamp, not just slid in place.

There's no reason not to use the top ones, but be aware that there are limits to the number of turns in conduit. I think some boxes even have side knockouts, and if yours does, there's plenty of reason to use them. Note that there are also dual-clamps available, where you could combine a few cables to go through a single bottom knockout and free up one of the holes that's there. Its also not unheard of to just put several cables through the same knockout/single-clamp.

Have you considered a slightly different solution of flex armored cable/conduit? I'm thinking Teck 90 or something similar. Note you would probably still need to worry about the minimum bend radius while getting the final bend to go to the HPWC.

You should plan to use the rear connection method to the HPWC even with conduit, IMHO. Be aware of the maximum size of knockout.

 

[howardnj]

Hello,

I'm planning to install the Wall Connector outside my garage. It's an unfinished garage, so just studs & plywood on the inside, and vinyl siding & a sheet of insulation on the outside.

My circuit breaker panel is right next to the garage door, and I'll put the WC either right next to that (but outside), or on the other side of the garage door. So my wire run will be either about 5 feet or about 18 feet.

I've run a similar circuit before when I put in the 240V line for my mini-split A/C unit, but that's a much lower current device.

From reading other threads here, and the WC manual, I see I need a non-GFCI 60A breaker.

And I should use #6 wire for 48A charging (80% continuous load on the 60A circuit).

I plan to use one of the rear entry ports on the WC wirebox.

Question #1: I assume I cannot use 6/2 romex for this, since romex is not for use outdoors? Even though, with rear entry, it wouldn't *exactly* be running outdoors, except for the portion that's inside the WC...

So that means using THWN wire, then.

Question #2: THWN must be run inside a conduit, right?

Question #3: I've read that I can use #10 wire for the ground even while using #6 for the two load lines; is that accurate?

Question #4: What's the best kind of bushing/fitting to secure the conduit to the rear of the WC, given that it'll be sort of half inside the wall?

Final question: My circuit breaker panel currently has all the circuits coming in through the bottom, but there *are* knockouts on the top of it. Is there any reason I can't use the top ones?

Thanks for any advice.

I think what you should do is hire a qualified local electrician that will apply for permits, use quality parts, schedule the inspection, and submit any paper work for possible rebates

 

[fiehlsport]

#6 Romex is not permitted for 48A charging, only 40A.

You need #6 THHN or THWN in conduit (flex or PVC) to meet code for 48A on a wall connector.

#4 Romex qualifies as well, but only comes in 4/3 (allegedly), so you're paying for copper you don't need. (No neutral required)

I believe you can downgrade the ground to #8 or #10 - I'm not an electrician, not sure which one.

 

[jcanoe]

I have 12/3 Romex inside my garage for powering lights, the garage door opener and a receptacle with 120V/15A outlets. The Romex is at a height above 7 ft except where it comes down to 4ft above the floor for switches and a receptacle box.

I also have a 240V/50A circuit and NEMA 14-50 receptacle in my garage that was installed using metallic clad (MC) wiring (might be 6/3). The 240V circuit installation was performed by a master electrician and was inspected. So while MC is not approved for use underground or in a wet or damp environment it can be used inside a garage, at least here in Maryland.

 

[MN-MS100D]

I would feed the HPWC from the bottom to maintain the integrity of the NEMA 3R enclosure. Top mount or rear mount would be to tougher to keep raintight.