Burnt wire in the wall charger

[jeeden]

I feel like I can't add anything to ALL of the above, but feel compelled to comment. IMO the clamp is not the cause of the overheat, but the #1 indicator of how bad the install is. Usually these threads are "oh, the electrician isn't up on the code.and put in a smaller breaker and wire," but that would still be safe, just keep tripping the circuit, and basic things like clamps etc have been code forever.

Also, I'm not a super stick in the mud about everything, but having that much amperage going through an exposed wire like that makes.me nervous. A kid could grab it, hand on it (how long until it is holding back garden tools or something which I have been known to do with Romex) and if there is one imperfection in the shielding it is a race between your heart and the breaker (a 70amp one!) to see what quits first.

There are a lot of electricians that are still learning about EV charger installs and have made errors about installing them with wiring based on non-continuous loads like the discussion above with Romex versus THHN. That said this electrician broke those codes and probably the codes before that and the ones before that by 35 years by not doing clamps.

I recommend what everyone said to go with: THHN in conduit. It lets you get 6 gauge wire and you don't have to wrestle it like an anaconda. As mentioned many of the chargers like the Rivian charger in my autel maxi charger which I love have a hard time with any wire on the terminal blocks that's bigger than 6 gauge.

Just to recap in summarize what everyone has said for anyone reading this thread in the future:

• Clamps on the charger and panel
• Conduit between
• Torque the terminal screws

For the 48 amp rating and because the code calls for 80% max continuous use load which for 48 amps demands all the components of a 60 amp circuit, if 40 amp demands all the components of a 50 amp circuit (keep this in mind if ever charging off an extension cord at a relative's house or airbnb):

• 60 amp breaker

And

• 6 gauge THHN in 3/4" conduit or luquid tite (recommended)

Or

• 4/3 Romex in conduit

I'm sorry this happened to you but I'm glad you're okay. Not to be an alarmist but this was a really big deal. This is the kind of thing that went up by the 11:00 news where they talk about a improperly installed EV charger caught a house on fire. Of course the headline is "EV catches on fire"

I agree with everybody that I wouldn't have him do the work again but I would be all up in his business and talking to his boss. Yeah, it's irritating that you've got a burned up EV charger too. I'd say at this point compensation would be the satisfaction of dreaming out whoever on the phone, getting them to buy you a new charger, refunding your money for the install.

They don't agree of course you could always go see what the local electrical inspector says and make sure he knows who installed it...

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[DucRider]

Thank you. My electrician told me the cable is rated for 50A and that's probably what's caused this since I was pulling 48A.

The wire size is not the cause, and is in fact the largest size allowed when installing the Rivian Wall Charger.
The 6 awg wire itself is rated for 75 amps, but when incorporated into NM-B the extra insulation reduces the allowed current to 55 amps.
The section of burned wire was not in the jacket and it is obvious that the connection was the source of the problem. It is most common that too little torque causes such issues, but over torquing can damage the wire, cut strands, cause arcing, etc. and show the same burn pattern as a result.

The entire install is a mess and I would not trust the "electrician" that was responsible. It is also obvious that there was no permit or inspection as this would fail before an inspector got within 10'.

 

[John Binford]

Save yourself from a waste of time and money, (dealing with an insurance company.) License electrician company. To much at stake here, trust me! You will sleep better! NOT GOOD!!!

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