overloaded ? 60amp Circuit breaker melts wire

[Feartoy]

I have the Tesla home charger set up on its own 60amp circuit. ( had an electrician do it )
It tripped the Circuit breaker the first charge they returned and replaced the circuit breaker.
worked good for a few weeks then it tripped the circuit breaker so I reset it and everything seems good. My electrician said you have a 100amp panel and your pulling max out of it .. ( I charge at midnight to 6am ) he said drop the amps so I did.
just for giggles I charged yesterday and noticed the panel is hot .. checked the temps and it was getting really hot .. from 55 before starting and 138 on the breaker. Thinking the breaker was bad I went to replace the breaker and noticed the black wire was burnt bad. So i stopped and now waiting on the electrician.

Anyone else have a 100amp panel and can’t charge at 45 amps ?

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[HaulingAss]

I have the Tesla home charger set up on its own 60am circuit. ( had an electrician do it )
It tripped the Circuit breaker the first charge they returned and replaced the circuit breaker.
worked good for a few weeks then it tripped the circuit breaker so I reset it and everything seems good. My electrician said you have a 100amp panel and your pulling max out of it .. ( I charge at midnight to 6am ) he said drop the amps so I did.
just for giggles I charged yesterday and noticed the panel is hot .. checked the temps and it was getting really hot .. from 55 before starting and 138 on the breaker. Thinking the breaker was bad I went to replace the breaker and noticed the black wire was burnt bad. So i stopped and now waiting on the electrician.

Anyone else have a 100amp panel and can’t charge at 45 amps ?

That's why I install my own chargers. I sleep better at night knowing I did it right.

From what I can tell from your story and photos, this has nothing to do with the amperage rating of your panel, it has to do with excessive resistance at the terminal on your breaker, probably due to an oxidized wire that was improperly formed and inserted (but it's impossible to tell after the insulation burned). It does look like some of the strands were bent during installation. Careful workmanship is important here and too many "professional" electricians value time and money over quality.

I advise everyone to monitor temps on their load center after any new install for excessive temperatures. because if it gets too warm on a new install, it's only going to get worse after it thermally cycles a few hundred times.

BTW, that is not a valid way to use an infrared non-contact thermometer. It depends upon the model, but you will generally get the smallest measuring spot at 1-3 feet from the area you are measuring. To burn the insulation off, it would have had to have been many hundreds of degrees.

Edit: And throw that breaker away, it looks like someone has damaged the screw that holds the red wire in. I'm not sure how that could happen with a competent electrician.

 

[TwiztOG43]

It’s definitely an improper connection to that breaker. Probably was not torqued to spec and as seen in your photos some of the strands bent causing high resistance and arching.

Only other concern is that it tripped the “first” breaker. I would question if the wires to the charger were intact to begin with or if the sheathing may have been compromised at some point during the install.

 

[Feartoy]

It’s definitely an improper connection to that breaker. Probably was not torqued to spec and as seen in your photos some of the strands bent causing high resistance and arching.

Only other concern is that it tripped the “first” breaker. I would question if the wires to the charger were intact to begin with or if the sheathing may have been compromised at some point during the install.

I Forgot The first breaker they used was the 50amp that use to power a spa 25 years ago. They replaced it with a 60amp. I had to go back and look at the pictures.

 

[HaulingAss]

I Forgot The first breaker they used was the 50amp that use to power a spa 25 years ago. They replaced it with a 60amp. I had to go back and look at the pictures.

Things are not adding up with respect to choices your electrician made.

It sounds like the electrician originally used the same wire and breaker that were installed for the hot tub to feed the Wall Connector but he didn't turn the Wall Connector down to 40 amps to account for the 50 amp breaker? That would explain a lot about why the old breaker was tripping.

But then it sounds like he came back and installed a 60-amp breaker on the same wire? The wire may not be adequate to use on a 60-amp circuit.

In any case, that wire cannot be reused. And it would be dumb to reuse the same "electrician". None of this is rocket science, but you do have to make sure every component, and every connection, is up to the task. This requires a "no-compromise" way of thinking, every step of the way. It's obvious that did not occur here.

 

[TwiztOG43]

I Forgot The first breaker they used was the 50amp that use to power a spa 25 years ago. They replaced it with a 60amp. I had to go back and look at the pictures.

Things are not adding up with respect to choices your electrician made.

It sounds like the electrician originally used the same wire and breaker that were installed for the hot tub to feed the Wall Connector but he didn't turn the Wall Connector down to 40 amps to account for the 50 amp breaker? That would explain a lot about why the old breaker was tripping.

But then it sounds like he came back and installed a 60-amp breaker on the same wire? The wire may not be adequate to use on a 60-amp circuit.

In any case, that wire cannot be reused. And it would be dumb to reuse the same "electrician". None of this is rocket science, but you do have to make sure every component, and every connection, is up to the task. This requires a "no-compromise" way of thinking, every step of the way. It's obvious that did not occur here.

Based on the photos, it does not look like the THHN wires used is 25 year old. Seems more like an install failure.

 

[M0unt41nm4n]

I have the Tesla home charger set up on its own 60amp circuit. ( had an electrician do it )
It tripped the Circuit breaker the first charge they returned and replaced the circuit breaker.
worked good for a few weeks then it tripped the circuit breaker so I reset it and everything seems good. My electrician said you have a 100amp panel and your pulling max out of it .. ( I charge at midnight to 6am ) he said drop the amps so I did.
just for giggles I charged yesterday and noticed the panel is hot .. checked the temps and it was getting really hot .. from 55 before starting and 138 on the breaker. Thinking the breaker was bad I went to replace the breaker and noticed the black wire was burnt bad. So i stopped and now waiting on the electrician.

Anyone else have a 100amp panel and can’t charge at 45 amps ?

Check your wires. Are you 4g or 6g? 4G shouldn't melt a thing. 6g gets warm... but code says you CANNOT use 6g in ROMEX. You must use 6g THHN (stranded inside conduit).

 

[Feartoy]

Things are not adding up with respect to choices your electrician made.

It sounds like the electrician originally used the same wire and breaker that were installed for the hot tub to feed the Wall Connector but he didn't turn the Wall Connector down to 40 amps to account for the 50 amp breaker? That would explain a lot about why the old breaker was tripping.

But then it sounds like he came back and installed a 60-amp breaker on the same wire? The wire may not be adequate to use on a 60-amp circuit.

In any case, that wire cannot be reused. And it would be dumb to reuse the same "electrician". None of this is rocket science, but you do have to make sure every component, and every connection, is up to the task. This requires a "no-compromise" way of thinking, every step of the way. It's obvious that did not occur here.

I agree the wires need to be replaced. The wire is new or was new you can or could tell by the color compared to the OLD wires. I trust they will come make it right.
The good part is the charger is only a few feet away from the panel and they don't have to pull from one end of the house to the other. It's less than 3 feet.
I think you are right that the connection at the breaker is the point of failure and not a 100amp panel feeding 48a draw and a home load at 1am the problem. ( im not using the microwave,diswasher,ac,vacuum,roasting a turkey and charging the truck at 1AM ) I was thinking it was a 100amp panel problem...

 

[Feartoy]

looks like they used 8. Hmmm

 

[HaulingAss]

I agree the wires need to be replaced. The wire is new or was new you can or could tell by the color compared to the OLD wires. I trust they will come make it right.
The good part is the charger is only a few feet away from the panel and they don't have to pull from one end of the house to the other. It's less than 3 feet.
I think you are right that the connection at the breaker is the point of failure and not a 100amp panel feeding 48a draw and a home load at 1am the problem. ( im not using the microwave,diswasher,ac,vacuum,roasting a turkey and charging the truck at 1AM )

It also looks like there is some duff or debris piling up inside, near the top of the service panel that could impact the connection between the breaker and buss bars. That needs to be cleaned out and the condition of the contact points should be inspected for burning/arcing/oxidation.

I can't really tell what is going on up there, but it doesn't look good.

 

[eswimm]

Sounds like basically everything is wrong. Was your "electrician" licensed? That needs to be 6 AWG THHN for 60A (48A charge rate). Ironically, the original 50A breaker and that wire was probably fine, so long as the wall connector was configured for a 50A breaker (40A charge rate). I bet the strands were splayed by the 1st breaker and the electrician bent them installing the 2nd. If your panel was overloaded, the main breaker would trip, it wouldn't melt the wire. The wire melted because it was too thin for the task and the install was botched. 50A (40A) would still be better than the mobile connector (32A) if you really don't have the capacity for a 60A breaker, but that all depends on what the typical load is on that panel.

 

[jjenkins]

That's why I install my own chargers. I sleep better at night knowing I did it right.

From what I can tell from your story and photos, this has nothing to do with the amperage rating of your panel, it has to do with excessive resistance at the terminal on your breaker, probably due to an oxidized wire that was improperly formed and inserted (but it's impossible to tell after the insulation burned). It does look like some of the strands were bent during installation. Careful workmanship is important here and too many "professional" electricians value time and money over quality.

I advise everyone to monitor temps on their load center after any new install for excessive temperatures. because if it gets too warm on a new install, it's only going to get worse after it thermally cycles a few hundred times.

BTW, that is not a valid way to use an infrared non-contact thermometer. It depends upon the model, but you will generally get the smallest measuring spot at 1-3 feet from the area you are measuring. To burn the insulation off, it would have had to have been many hundreds of degrees.

Edit: And throw that breaker away, it looks like someone has damaged the screw that holds the red wire in. I'm not sure how that could happen with a competent electrician.

I am an electrician, this really only happens when the wire attached to the breaker is not connected properly it creates massive amount of heat at the lug, the copper conducts the heat down the wire and melts the insulation. Note that this happened only on one of the conductors. If it was truly over loaded both wires would be damaged (assuming they are both the same size wire). Replace the breaker and wire to the EVSE, better yet replace and upgrade your panel.

 

[CyberGus]

It is incorrect to install 8AWG wire (max 40A) connected to a 50A breaker. In this configuration, the melting wire is the safety shut-off for the circuit breaker

 

[eswimm]

It is incorrect to install 8AWG wire (max 40A) connected to a 50A breaker. In this configuration, the melting wire is the safety shut-off for the circuit breaker

8 AWG THHN is actually rated for 55A at 90C, which would have been fine for the 50A breaker, but not for the 60A and not with several strands bent out of the terminal. 8 AWG Romex is only good for 40A.

 

[REM]

I'd be very hesitant to use his service anymore. Also, I'd ask for a refund.

Melted wire after a visit from an "electrician" is NOT good.

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