New house build Wire sizing for HPWC.

[JeoTes]

We are having a house built and we just went though the pre drywall meeting. The electrician installed 6/3 wire in my garage to the panel in the basement. There are no breakers in the panel yet but I assume he is going to put a 50amp breaker in since he is using 6/3 rated at 55amps. I talked to the PM about re-running the correct wire for a 60amp breaker but it will cost extra. He hinted that after inspections are done on Monday, I could come in and run the correct wire before any drywall goes up in the garage, so I will probably do this myself he just asked to not hook anything up and he will have the electrician check and finish the work , I'm just not sure what wire I should use. Once drywall goes up everything will be enclosed and the run from the garage to the basement is about 40'.

If I just decide to leave the 50amp breaker can I set the charge to 44amps on that 50amp breaker?

 

[Ralbright]

Wasted effort imo. I used 6/3 for my hpwc for ease of install.

You can set you’re breaker size when configuring your charger the first time.

 

[TheBeej418]

You'll get 40 amp max output off of a 50amp breaker.

I bought a metallic 6/3 wire that has THHN wire in order to run a 60-amp breaker but for general driving, the car is going to be charged when you get to it each day whether it's 50-amp or 60-amp breaker. I wanted to go 60-amp not knowing how the technology will change or what brand car I may find myself driving in the future.
6/3 Stranded Metal Clad Copper Conductor 600V Aluminum Armored Cable

 

[ucmndd]

The wall connector doesn’t have a 44 amp setting.

If you want to use NM “Romex” bundled cable you need 4 awg conductors by code for 60 amps. The wall connector doesn’t use the neutral so you’d really only need 4/2 cable but that doesn’t really exist. Or you can run individual 6 awg THHN conductors inside conduit. The cable @TheBeej418 mentions above would be a great choice if you don’t want to fish your own.

 

[JeoTes]

Wasted effort imo. I used 6/3 for my hpwc for ease of install.

You can set you’re breaker size when configuring your charger the first time.

What did you set your breaker to?

 

[ucmndd]

What did you set your breaker to?

The only correct answer for that scenario is 50 amps. But lots of people use 6/3 romex with 60 amp breakers. It’s definitely not code, but it happens all the time.

 

[Ralbright]

The only correct answer for that scenario is 50 amps. But lots of people use 6/3 romex with 60 amp breakers. It’s definitely not code, but it happens all the time.

Technically it’s rated to 55amps. And code does allow a small roundup to 60amp if a 55 isn’t available if I remember correctly.

That said, my run is long, so I used a 50amp breaker.

 

[Consistent21]

You'll get 40 amp max output off of a 50amp breaker.

I bought a metallic 6/3 wire that has THHN wire in order to run a 60-amp breaker but for general driving, the car is going to be charged when you get to it each day whether it's 50-amp or 60-amp breaker. I wanted to go 60-amp not knowing how the technology will change or what brand car I may find myself driving in the future.
6/3 Stranded Metal Clad Copper Conductor 600V Aluminum Armored Cable

I had an existing 40 Amp breaker from an unused stove outlet. Panel was in my garage. I had the electrician run 60 A rated wire to the wall connector but kept the 40 A breaker. There was some cursing involved because the wire was so unwiedly. I have a Model 3 RWD so maximum I can charge at is 32 A. It's fine for now and I won't be upgrading anytime soon.

My 100 A service is marginal with a 40 A breaker. Probably would have needed to upgrade to 200 A with a 60 A breaker. That would have been very expensive.

We're in Ontario, Canada. Check your local electrical code for proper wire sizing.

 

[Plood]

I just had an install. Friend I bought the Tesla from said “use this guy, he does lots of these”. Without any discussion and with an extra charger given by my friend, I ended up at 40A. On a 50A breaker.

Spent $750 for the install that required conduit to the opposite side of a single garage.

6AWG I believe. Not sure how the system know what it’s connected to. Is that a setting in the charger set by the electrician?

 

[zoomer0056]

You'll get 40 amp max output off of a 50amp breaker.

I bought a metallic 6/3 wire that has THHN wire in order to run a 60-amp breaker but for general driving, the car is going to be charged when you get to it each day whether it's 50-amp or 60-amp breaker. I wanted to go 60-amp not knowing how the technology will change or what brand car I may find myself driving in the future.
6/3 Stranded Metal Clad Copper Conductor 600V Aluminum Armored Cable

I bought red, black and green THHN wires. Red and black #6 and green #8. I ran them from a 60amp breaker thru metal EMT conduit on the outside of the drywall to the wall connector. I used #8 for the ground to make it easier to run all three thru the conduit. #6 THHN is rated at 75 amps.

 

[ucmndd]

Technically it’s rated to 55amps. And code does allow a small roundup to 60amp if a 55 isn’t available if I remember correctly.

That said, my run is long, so I used a 50amp breaker.

You can use the round up rule IF your calculated load doesn’t exceed the rated ampacity of the wire. A wall connector configured for 48 amps is greater than 80% of 55 amps (continuous load), so that’s not gonna fly with 6/3 nm-b.

This particular horse has been beaten to a bloody pulp in countless threads. As I said, there’s only one correct answer per code. But lots of people do it wrong, and lots of AHJs don’t seem to catch it (although this conversation almost always comes up in the context of DIY unpermitted installs).

Will it be perfectly fine and almost certainly not burn your house down? Probably. Is it code complaint? No.

 

[ucmndd]

I just had an install. Friend I bought the Tesla from said “use this guy, he does lots of these”. Without any discussion and with an extra charger given by my friend, I ended up at 40A. On a 50A breaker.

Spent $750 for the install that required conduit to the opposite side of a single garage.

6AWG I believe. Not sure how the system know what it’s connected to. Is that a setting in the charger set by the electrician?

The new gen3 wall connector has a software setting for the amperage. You’ll need to connect it to wifi and log in to run the commissioning process if you want to change it.

 

[JeoTes]

You can use the round up rule IF your calculated load doesn’t exceed the rated ampacity of the wire. A wall connector configured for 48 amps is greater than 80% of 55 amps (continuous load), so that’s not gonna fly with 6/3 nm-b.

This particular horse has been beaten to a bloody pulp in countless threads. As I said, there’s only one correct answer per code. But lots of people do it wrong, and lots of AHJs don’t seem to catch it (although this conversation almost always comes up in the context of DIY unpermitted installs).

Will it be perfectly fine and almost certainly not burn your house down? Probably. Is it code complaint? No.

I'm sure it will be fine if I did, but I have bad luck with "I'm sure it will be fine". So I guess I be running THHN though conduit. Now I'm wondering if I should run wire that will be good for 80amp breaker for future updates.

 

[Ralbright]

I'm sure it will be fine if I did, but I have bad luck with "I'm sure it will be fine". So I guess I be running THHN though conduit. Now I'm wondering if I should run wire that will be good for 80amp breaker for future updates.

Or just run a 50 or 55 amp breaker and save yourself the time / money.

You’ll literally never notice the difference between 40 and 48 amp charging when your talking about overnight charging your Tesla.

 

[Proppilot]

I just had an install. Friend I bought the Tesla from said “use this guy, he does lots of these”. Without any discussion and with an extra charger given by my friend, I ended up at 40A. On a 50A breaker.

Spent $750 for the install that required conduit to the opposite side of a single garage.

6AWG I believe. Not sure how the system know what it’s connected to. Is that a setting in the charger set by the electrician?

That install is correct. #6 wire to a 50A breaker and charger set to 40 amps

 

[ucmndd]

I'm sure it will be fine if I did, but I have bad luck with "I'm sure it will be fine". So I guess I be running THHN though conduit. Now I'm wondering if I should run wire that will be good for 80amp breaker for future updates.

If you’re gonna fuss with it anyway, the nominal cost to go up to #4 wire is probably worth it. You don’t want to be digging in drywall after the fact…

 

[Plood]

I sure wish the electrician had offered the #4 option. But that means bensons heavier conduit and pulling stiffer wire. Harder work.