Electrician screening

[neoY]

Hey All,

I have had multiple electricians provide quotes to install a wall charger and one of them is saying that I need to upgrade the service to my house from 200A to 300 or 400A (which they can do). The rest of them did not bring this up as a concern with installing it.

The guy saying this is one from Tesla's electrician search list. I will be having another one from that list come in on Friday this week. I will update here what he says.

But wanted to post here to see if anyone else had this situation and any advise. The service to my house is 200A and I only have a electric dryer/washer and cooling HVAC. Rest of the appliances are gas. There are empty slots available in the exterior main breaker box. Thanks in advance for your responses.

 

[EVer Hopeful]

Interesting. I didn't know you could mix Square D with Eaton

Also the strip on the wires on the breaker in the top left of the panel is a little long, or maybe they could be pushed in a little further because there's bare copper showing

One question: there's a lot passing through the entry point I see the service and the service ground, but what's the big grey wire? Also, how come the supply to the HPWC goes back through that same opening?

 

[neoY]

Interesting. I didn't know you could mix Square D with Eaton

Also the strip on the wires on the breaker in the top left of the panel is a little long, or maybe they could be pushed in a little further because there's bare copper showing

One question: there's a lot passing through the entry point I see the service and the service ground, but what's the big grey wire? Also, how come the supply to the HPWC goes back through that same opening?

The Eaton ones (top left) are the HVAC breakers and the guy did point out its not allowed to mix anymore as it is a Square D panel. I guess this was in place years ago (house was built 2001).

Above this panel is the meter. The grey wire coming outward in the ‘before’ photo is the new wire he ran for the wall charger if that’s the one you referred to. That opening goes back into the crawl space.

 

[dogmodes]

How long is that run? It looks like he used 6/2 romex which shouldn’t be used above a 50A EV charger (42amp charging). Maybe my eyes are wrong but it doesn’t look like 4/2.

 

[ChrisMPK]

Maybe it's just me but I would hit that panel with a shop vac while the cover is off. Otherwise the install looks god. Wouldn't be a bad idea to correct the wire on that top left breaker as others have said.

 

[neoY]

How long is that run? It looks like he used 6/2 romex which shouldn’t be used above a 50A EV charger (42amp charging). Maybe my eyes are wrong but it doesn’t look like 4/2.

About 20 ft. No idea about romex will ask the tech.

 

[Jschoef]

In regards to Romex. I’ve read a lot and spoke to a few electricians about this. As Tesla docs state, 6AWG is the minimum to go for maximum charge. 6/2 Romex is just that but it’s only related for 55 amps and you need a 60amp breaker. I think most 6AWG is rated for only 55amps.

I am no expert here at all but I have read on other sites and spoke to a few electricians and they all say it’s fine for the 60amp breaker to protect the wire as long as the actual draw is less then 55amps. As most know here, the Tesla Gen 3 Wall Connector is maxed out at 48amps.

I am running the 6-2 also and all seems good with the wire barely getting warm at the panel. If I didn’t already install it, I’d look into 4AWG.

 

[dogmodes]

In regards to Romex. I’ve read a lot and spoke to a few electricians about this. As Tesla docs state, 6AWG is the minimum to go for maximum charge. 6/2 Romex is just that but it’s only related for 55 amps and you need a 60amp breaker. I think most 6AWG is rated for only 55amps.

I am no expert here at all but I have read on other sites and spoke to a few electricians and they all say it’s fine for the 60amp breaker to protect the wire as long as the actual draw is less then 55amps. As most know here, the Tesla Gen 3 Wall Connector is maxed out at 48amps.

I am running the 6-2 also and all seems good with the wire barely getting warm at the panel. If I didn’t already install it, I’d look into 4AWG.

I’m not an expert either. It’s not the 6AWG that’s rated for 55A it’s the plastic sheathing of the romex that lowers the ampacity. More then likely the wire inside is the proper thhn which would be fine if it was run in conduit, which would give it a bit of room for heat to dissipate. I agree it’s probably fine and there are probably 1000’s of them installed that way, but it is against the EV charging codes to use it that way. Just want to point it out so the person using it knows it’s not perfect. Me personally I’d probably dial it down at the charger but I get a bit paranoid. When talking with sparkys the disconnect seems to be you are allowed to under wire in some circumstances, like if it was an intermittent use oven. But they specifically call out EV charging at the 80% rule because of the long load times.

 

[dogmodes]

About 20 ft. No idea about romex will ask the tech.

He’s going to tell you it’s fine. I’d search the forum a bit for romex, or 6/2, 6/3, etc. You’ll find dozens of long long threads that go into it.

 

[SilverString]

With a 20 ft run it will be fine. Keep in mind the NEC spec is based on resistance at 100ft.

 

[Kandiru]

They are just looking for a bigger payday. I have 200A and run two ACs and charge car no issues.

 

[Jschoef]

With a 20 ft run it will be fine. Keep in mind the NEC spec is based on resistance at 100ft.

Interesting on the Nec Spec being 100ft. Mine is a 30ft run…so does the mean it is actually rated higher then 55Amps or they don’t state that?

 

[SilverString]

Interesting on the Nec Spec being 100ft. Mine is a 30ft run…so does the mean it is actually rated higher then 55Amps or they don’t state that?

There could be other issues but wire length certainly plays in to the equation. I am not a "licensed" electrician but I do know that the heat is created by the total wire resistance, and the resistance is calculated according to wire length. All I can tell you for sure is that the resistance of #6 at 30ft is approximately 1/3 of what it would be at 100ft. So it follows that you will get less heat, which is the primary concern.

 

[neo1738]

So when I built my house a year ago we wired for 100A to the breaker in the garage. Didn't have any outlet just a plate and the wire wasn't hooked to the panel. Had them come back to install wall charger and hook up 60A breaker to our panel and added an outlet to our pantry and they only charged $125. Looking at this guess my electrician is a great deal lol.

 

[Jschoef]

So when I built my house a year ago we wired for 100A to the breaker in the garage. Didn't have any outlet just a plate and the wire wasn't hooked to the panel. Had them come back to install wall charger and hook up 60A breaker to our panel and added an outlet to our pantry and they only charged $125. Looking at this guess my electrician is a great deal lol.

Id say so! What is your voltage when you are charging? I'm around 231-235. Im in NH, so I'm wondering what it will be at when its actually hot out.

 

[neo1738]

Id say so! What is your voltage when you are charging? I'm around 231-235. Im in NH, so I'm wondering what it will be at when its actually hot out.

240-242v 48A heated garage

 

[Jschoef]

240-242v 48A heated garage

I just looked at your pics and Romex 6AWG is black. Yours is grey so im thinking with the good voltage, you have some sort of 4AWG wire. Again, I'm no expert here!

 

[neo1738]

I just looked at your pics and Romex 6AWG is black. Yours is grey so im thinking with the good voltage, you have some sort of 4AWG wire. Again, I'm no expert here!

Talking to the right guy? I don't have any wire to my HPWC showing it's completely hidden in the walls/floor as it was put in when I built the house. I wouldn't be surprised though as I had my electrician install wire capable of 100A (back when tesla had up to 80A chargers).

 

[Jschoef]

Talking to the right guy? I don't have any wire to my HPWC showing it's completely hidden in the walls/floor as it was put in when I built the house. I wouldn't be surprised though as I had my electrician install wire capable of 100A (back when tesla had up to 80A chargers).

Lol, nope. Sorry!

 

[neo1738]

Lol, nope. Sorry!

lol no worries!

 

[marx1]

6awg Non-metalic sheathed cable (of ANY KIND) is not permitted for a 48a charge rate/60a breaker. The issue is it's rated at 60c. at 60c it's only 55amps, and chargers require the cable to be rated at 125% of the circuit load. This means at 48a charge, your wire/breaker must be rated at 60a.

To get 60a rating with Non-metalic sheathed cable you must use 4AWG. The pictures do not look like 4awg. You need to have the wire replaced with 4/2 or run THHN (90c rated) in some form of conduit.

The main issue is the wire WILL get hot under charge. the hotter it gets the more resisitance, turnint it hotter, and if the breaker is too big it will never trip and you have a fire.

You can down-rate to a 32a charge (40a breaker) or 40a (50a) breaker and use your current cable. There is a reason you get a permit for this stuff. If you had one, you wouldn't have passed inspection.