Wire gauge (AWG) for HPWC (Telsa Wall Connector)

[gilscales]

While I might have an electrician come and run the wires and hook it up, I want to run the conduit because I need to send it behind a partial wall and I am also picky on how things are run in my house...LOL

Here is what I want to do....let me know if I'm crazy.

Have about a 40' straight run from one side of the house to the other in the basement. I want to run 1" conduit from the panel to the other end of the house to a box. Run 3- #4 wires and a ground (future proof with a neutral if ever needed). then at the box switch to a 3/4" conduit to punch to outside and to the wall adapter outside. I will then cap the neutral in the box and run the 2- #4 and a ground out to the wall connector.

Before you run the 1", check your fill percentage, you do not want to be over 40% as this is the max with any conduit running 3 wires or more, also pulling the wire will be much harder, looks to me like you'll want 1 1/4" for sure, you can use this online conduit fill calculator to check
Conduit Fill Calculator - Best Online Conduit Fill Calculator

 

[Mujenpwr]

I did install I used #3 THHN (#8 for ground) 100a breaker .. less than 5foot run..ur fine with #6

It’s ok to use a smaller gauge for the ground? So if it was a 60amp circuit #6 THHN for both hots and say #8 THHN for ground is ok?

 

[Rocky_H]

It’s ok to use a smaller gauge for the ground?

Yes, that is normal that the ground wire is thinner than the "conductor" wires.

So if it was a 60amp circuit #6 THHN for both hots and say #8 THHN for ground is ok?

I don't think I can give an exact answer on this. There is a table in the NEC of with a given size of conductor wire in a circuit, how big the ground wire has to be. It scales a bit, and I don't remember which exact wire sizes go together.

 

[ucmndd]

#10 ground is acceptable with #6 conductors. This is what you’ll find in 6/3 Romex.

 

[Mujenpwr]

#10 ground is acceptable with #6 conductors. This is what you’ll find in 6/3 Romex.

Thank you for the response. I did look up the NEC grounding section and saw the same. I appreciate everyones responses.

 

[syavko]

Hi. I own a Tesla model 3 and i’m looking to install at home charging wit a NEMA 14-50. I’m looking to install a 8 gauge 4 conducted why but they’re really expensive in local stores like home depot and lowe’s. Does anyone knows anywhere I can get this wire for cheaper? Thanks.

 

[jebinc]

Hi. I own a Tesla model 3 and i’m looking to install at home charging wit a NEMA 14-50. I’m looking to install a 8 gauge 4 conducted why but they’re really expensive in local stores like home depot and lowe’s. Does anyone knows anywhere I can get this wire for cheaper? Thanks.

You need 4 or 6AWG

 

[syavko]

8AWG

 

[Rocky_H]

Oh jeez. People are giving opposing recommendations when there isn't enough information to really give an answer yet. Any time someone just says the gauge number but doesn't say what type of wire or cable or conduit or not, there just isn't enough information, because the different wire types have different amp ratings. Also, the person never said what amp rating of circuit is being done!

I own a Tesla model 3 and i’m looking to install at home charging wit a NEMA 14-50.

A 14-50 is allowed to be done on either a 40 or 50A circuit. Which are you planning?

I’m looking to install a 8 gauge 4 conducter

Are you talking about 8 gauge individual wires that you put in conduit? Or is this like inside a wall, where you are using Romex cable (NM-B)? The amp ratings are different for those.

It definitely wouldn't need 4 gauge, but it might need 8 or 6, depending on the answers to some of these questions.

 

[syavko]

30А

 

[Rocky_H]

A 14-50 is allowed to be done on either a 40 or 50A circuit. Which are you planning?

30А

Uh, what? That's not what I was expecting. If you are going to do a 30A circuit, then you should use a 14-30 outlet, not a 14-50 outlet. The second number refers to the amps of the circuit it is supposed to have.

 

[syavko]

Ну купил переходник 14-50 для мобильного ЗУ на 30А, так какой кабель нужен на 220 вольт 30А

 

[Rocky_H]

With some Google translate, I get this:
Well, I bought a 14-50 adapter for a 30A mobile charger, so what kind of cable is needed for 220 volts 30A

You should get a 14-30 outlet and a Tesla 14-30 plug for your charging cable.
For a 30A circuit, that can use 10 gauge wire, either with Romex cable or with wires in conduit. Here is an amp table that shows this:

Cerrowire Resources - Ampacity Charts

Ampacity is the maximum current that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. Cerrowire's ampacity chart helps calculate the load requirement for a circuit.

www.cerrowire.com

 

[syavko]

Где можно купить кабель 8. И розетку Чтобы было дешево. Купил переходник 14-50

 

[Sorny]

6/3, 40A breaker, ~25' run is what I put in.

 

[Keninblaine]

6/3, 40A breaker, ~25' run is what I put in.

Not sure why you'd use a 40A breaker on 6/3. With 6/3 romex you could have used a 50A breaker, giving you 40amp max current (using 80% rule). My car is set to charge at 40amps on 6/3 romex to my Tesla Wall charger and it has worked great for a year now. I have an additional 14-50 NEMA charge receptacle (Hubbell) on the other side of the garage, on a separate 50A breaker, which also works great.

 

[DevZ]

Not sure why you'd use a 40A breaker on 6/3. With 6/3 romex you could have used a 50A breaker, giving you 40amp max current (using 80% rule). My car is set to charge at 40amps on 6/3 romex to my Tesla Wall charger and it has worked great for a year now. I have an additional 14-50 NEMA charge receptacle (Hubbell) on the other side of the garage, on a separate 50A breaker, which also works great.

On the same note, you can only charge at 32A max on a 40A breaker. 40A charge rate should not be used on a 40A breaker.

 

[Sorny]

Not sure why you'd use a 40A breaker on 6/3. With 6/3 romex you could have used a 50A breaker, giving you 40amp max current (using 80% rule). My car is set to charge at 40amps on 6/3 romex to my Tesla Wall charger and it has worked great for a year now. I have an additional 14-50 NEMA charge receptacle (Hubbell) on the other side of the garage, on a separate 50A breaker, which also works great.

100A main panel... 40A breaker and upsized wires. Voltage drop is about 2V or less. Wire never gets warm. But, nope, I didn't think about what I installed at all.

 

[janthony6]

I have 2 wall connectors gen 3. On the side of my garage closest to the panel, I have #6 stranded on a 60amp breaker. The wire length is roughly 8ft.

On the other side of the garage, we recently opened the walls to run a conduit inside. We used #2 stranded to future proof. it fits with no issue inside the wall connector. we have it on a 60 amp breaker too.

the 8ft wire is much easier to change out for a #4 or 3 or 2 in the future but when opening the walls and going across the garage, it would be a major PITA to try to change out that wire later.