Wall charger gen3

[Papagiorgio]

I have a gen 3 wall charger I am going to have installed and was thinking if I bought the electrical cable that I’ll need to hook up to my panel it could save me money rather than letting the electrician provide it. I need 100ft I just don’t know what that cable is called can anyone help with this info

 

[Rocky_H]

We can't help much until we know what your install looks like. You need to use different kinds of things, depending on whether it's inside walls or outside walls on the surface in conduit, or is it buried underground to a detached garage, etc. etc. etc. You have given no details.

 

[Papagiorgio]

The plan is to run the wire from the panel through my crawl space up the wall through the attic and drop the wire down behind the wall into the garage no conduit. I believe people are using a 6/3 or 6/4

 

[Rocky_H]

The plan is to run the wire from the panel through my crawl space up the wall through the attic and drop the wire down behind the wall into the garage no conduit. I believe people are using a 6/3 or 6/4

OK, so it sounds like all of this distance is crawlspace and inside walls, so it's called Romex cable, which is used for that. The way they name it, is that the first number is the wire gauge thickness, and then the second number after the / is how many main conductors it has, not counting the separate bare ground wire, which is also inside. The wall connector just needs the two hot conductors, and the ground, so that would be 6/2. There wouldn't be anything wrong with using 6/3, but that's just going to be more expense for an unused wire all that way, which is just going to get capped, so I wouldn't do that.

Also, are you sure about the wire gauge? What size circuit are you wanting to put in, in number of amps? If it's a 60A circuit, you would need a bigger wire gauge than 6. But if smaller, like a 50A circuit, that would be fine. (And keep in mind, if you weren't aware, that wire gauge numbers go opposite of size, so smaller gauge number is thicker wire.)

 

[Papagiorgio]

60a circuit I am hoping to be able to use the gen 3 to its full ability

 

[Rocky_H]

60a circuit I am hoping to be able to use the gen 3 to its full ability

Then you would need 4 gauge wire: Romex 4/2. That's maybe not too common, so not sure if you can just find it on the shelf locally, but you can order it.

*Edit* References are good, so you know I'm not just spouting off things on the internet.
Ampacity Charts - Cerrowire

That's a table of what type of wire and what thickness is rated for how many amps. The first column that says "NM-B" is that Romex cable I was referring to. So you can see to meet a 60A circuit rating, you need the 4 gauge.

 

[Papagiorgio]

Thank you for the valuable info I am having trouble even finding the 4 gauge wires online

 

[Rocky_H]

I did just find that apparently no one makes 4/2 Romex. It's a strange hole in the supply/demand world there.

There may be other cheaper options since you are talking about a 100 foot kind of run, which is pretty long, so cost may add up. You can use larger gauge aluminum cable possibly for most of the distance to get it to your garage to a junction box, and then switch to a short run of copper for the final bit to the wall connector. But those are getting into more details than I am familiar with and would be something to consult with an electrician about.

 

[Brandon#]

6/3 should be fine. You’ll only pull 48a.

However, I’d let the electrician make the final call. Saving a few $ isn’t worth the headache if he shows up and doesn’t like your choice in wire.

 

[Rocky_H]

6/3 should be fine. You’ll only pull 48a.

No, it's not fine--that's not how that works. You have to use wire capable of the rating of the circuit. The continuous current is 48A, but because it's continuous, code requires that you have to spec the circuit for 1.25 times that amount of amps, which is a 60A rated circuit, and you can't use 6/3 Romex for a 60A circuit. That's why you would have to go up to 4 gauge.

 

[MY-Y]

I used 4-3 just in case I wanted to use a 14-50 in the future. My electrician said the supply house has 4-2 as well.

You can find 4-3 online. It's difficult to pull through finished walls, especially going through the studs (which i had done for my HPWC).

4-3 W/G NM-B Wire Black

 

[Brandon#]

No, it's not fine--that's not how that works. You have to use wire capable of the rating of the circuit. The continuous current is 48A, but because it's continuous, code requires that you have to spec the circuit for 1.25 times that amount of amps, which is a 60A rated circuit, and you can't use 6/3 Romex for a 60A circuit. That's why you would have to go up to 4 gauge.

I’m not an electrician, and I’m not trying to pretend to be one on the internet . I trust the one that installed my charger as he has installed many before. Also here is what the manual says.

 

[MY-Y]

I’m not an electrician, and I’m not trying to pretend to be one on the internet . I trust the one that installed my charger as he has installed many before. Also here is what the manual says.

Yes, 6 gauge is fine if you have a 90*C wire like THHN in conduit. NM is 60*C rated and needs to be 4 gauge for a 60 amp (48 continuous) circuit.

 

[Papagiorgio]

I have also been trying to find an electrician to install this wall charger. I have been scheduling quotes from the people listed on the Tesla site. Does anyone know if I need to use a licensed electrician for warranty purposes

 

[jcanoe]

I have also been trying to find an electrician to install this wall charger. I have been scheduling quotes from the people listed on the Tesla site. Does anyone know if I need to use a licensed electrician for warranty purposes

You should use a licensed electrician for peace of mind. Also, you may want to have a permit pulled for the work, inspection by the county building/electrical inspector. This is an important consideration. If there is ever an electrical fire and your home owner's insurance underwriter learns that you installed unapproved modifications to your home's wiring they most likely will deny any claim against the insurance policy.

 

[MikeHolliday]

Ok, here is where you buy your cable. I have been dealing with them for years.

6/2 Copper MC Cable w/ Ground
The 100 ft. of cable will run you $190.00...

6/2 will work if you use MC Cable. MC Cable is rated at 90 degrees and will carry more current than 65 degree rated Romex.
http://www.cmewire.com/catalog/sec01-bwx/bwx-03-mc-amp.pdf 6 guage MC Cable is rated at 75 Amps.

It is also easier to pull than 4 guage Romex and gives better protection from external damage.

 

[Rocky_H]

That does have a certain caveat to it with using MC cable. It may be rated for the 90 degrees C condition by itself, but you can also be limited by any other temperature limits of other lugs, junction points, breakers, etc. And residential circuit breakers are never rated for 90 degree use, so it will probably still have to use the 75 degree column anyway for your amp limit, even when using MC cable.

 

[MikeHolliday]

The Tesla Wall Connector has 90 degree rated terminals. Even at 75 degrees the MC Cable can carry 65 Amps and you are only using a 60 Amp breaker with the Tesla Gen3 Wall Connector.

Gen3 Wall Connector Manual - Page 5 - Branch Circuit Conductors and Ground Wire • If installing for less than maximum power, refer to local electrical code to select correct conductors and ground wire size that are suitable for the chosen circuit breaker. • If installing for maximum power, use minimum 6 AWG, 90° C-rated copper wire for conductors. NOTE: Upsize conductors if necessary.

 

[jstjohnz]

If there is ever an electrical fire and your home owner's insurance underwriter learns that you installed unapproved modifications to your home's wiring they most likely will deny any claim against the insurance policy.

Sorry that is just not true.

 

[jcanoe]

Sorry that is just not true.

Please explain.