Wall charger gen3

[MikeHolliday]

If you use 6 guage wire (THHN, THW, THWN, SE, USE, or XHHW as they are rated at 75 degrees and can carry 65 amps), 2 Conductors and a gound which is called 6/2. You do not count the ground as a conductor. On 240 volts for a Wall Connector you do not use a Neutral. You have Line 1 (Referred to as L1) @ 120 volts 60 amp breaker and Line 2 (Referred to as L2) @ 120 volts 60 amp breaker. If you use 6/2 it cannout be Romex. Romex is only rated at 60 degrees and only can carry 55 amps. Since the wire needs to be rated at or higher than 60 amps when connected to a 60 amp breaker.

As I mentioned above Tesla even points this out in the Gen3 Wall Connector manual on page 5. "If installing for maximum power, use minimum 6 AWG, 90° C-rated copper wire for conductors. NOTE: Upsize conductors if necessary."

Once again, Romex is only rated at 60 degrees and 55 amps (correction from earlier post) and therefore cannot be connected to a 60 amp breaker.

 

[Rocky_H]

You are getting some things pretty confused.

The Tesla Wall Connector has 90 degree rated terminals.

I'm pretty sure it doesn't. The Gen1 and Gen2 ones were 75 degree C rated, I believe, and I don't see why the Gen3 would be different. Residential devices like everyone's circuit breakers would only be 75, and the wall connectors are generally consumer type devices, so they would probably match. The industrial 90 degree C ones would be more expensive, and they wouldn't have much reason to use those.

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.

I think you are misunderstanding what that is saying in the manual. The actual wires in side even NM-B are also 90 degree C rated individually, but when bundled in that sheath, they have to be treated with a 60 degree C rating as a whole. This has been talked about in other threads, like this:
Wall Charger what amp for breaker
And this comment points out section of NEC 334.80 of why NM-B can be treated as 90 C individual wires for some calculations, but treated as 60 C cable for some other calculations. Code is freaking complicated when you get into several types of derating factors.
Diy: Home High Power Wall Connector Installation

That part in the manual I think is just the more technical way of saying, "Use real 'house wiring' kind of wire that has that 90 C insulation."

 

[MikeHolliday]

The problem with Romex and why it gets a 60 degree rating is that the wire is bundled in a situation where it cannot cool properly. In conduct there is air circulating allowing some cooling. As an example, place a charging Cell Phone under a pillow and one on a table check back in a few hours and let me know what you find. This is the reason that BEV Vehicles are considered a continuous load. With a continous load there is a greater chance for the wiring to run warm especially if the wire is undersized. I have over $75,000 in my Model Y, why would I want to save typically under $50 for wire and have a potential to have a serious issue arise from doing so.

 

[Rocky_H]

The problem with Romex and why it gets a 60 degree rating is that the wire is bundled in a situation where it cannot cool properly. In conduct there is air circulating allowing some cooling. As an example, place a charging Cell Phone under a pillow and one on a table check back in a few hours and let me know what you find.

Yes, obviously. That is why Romex is lower temp rating like that.

This is the reason that BEV Vehicles are considered a continuous load.

Well, not really. They are because the old continuous load clause used to define it by at least 4 hours, and a large majority of the time, EVs are going to be charging for at least that long, and they didn't want people trying to play games with "Well, I'll only charge it for less than 4 hours and then take a break and then charge for less than 4 hours again. Tee hee!" So they just decided it was safer to always apply the "greater than 4 hours" continuous load kind of condition.

With a continous load there is a greater chance for the wiring to run warm especially if the wire is undersized.

Yes, of course.

I have over $75,000 in my Model Y, why would I want to save typically under $50 for wire and have a potential to have a serious issue arise from doing so.

Why are you being so argumentative and contentious? No one is suggesting trying to shortcut anything to save money on the wire or do anything dangerous. If Romex were made in 4 gauge or 3 gauge, it would be abundantly safe and code compliant for a 60A circuit, with the proper 60 degree C rating. It's just not available in gauges that large, so you need to use something else.