Scary Crackling Coming From NEMA 14-50 Outlet & Charger

Carl_P

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Hi everyone,

NEMA 14-50 outlet
Model 3 standard charger
Sits on 50 amp breaker on a copper line

Went out into my garage this morning to drive Model 3... didn't hear anything out of the ordinary. Car was plugged in.

Opened my car door. A/C in the car turned on basically to full blast (it's been hot). After a few seconds, I immediately hear a crackling, zapping type sound coming from the plug in the wall. I took a video but this site won't let me upload it. It sounded like electrical crackling

I listened for a bit to see if it would go away, but then decided after a minute that this was bad, and went down into the basement to shut off the breaker.

Any theories? Is the car pulling too much energy with the HVAC at full blast? Is the 50 amp breaker not working? Something worse?

Thanks,
CP
 

Needsdecaf

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1. Loose connection between the EVSE (box with the Tesla lights) and the plug head.
2. More likely, connections have loosened at the socket. Have an electrician check it out.
3. Least likely, your EVSE has failed.

Call an electrician.
 
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JasonF

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Either the wires are loose at the screw terminals behind the 14-50 outlet, or the 14-50 outlet has failed.

While you have the breaker off, remove the 14-50 outlet from the wall and check for loose screws. If the wires or outlet are burned, you're going to have to re-trim the wires and/or replace the outlet, or it won't be able to conduct efficiently and will heat up. Also look for burns on the wall box, it's possible too much insulation was trimmed and it's arcing against the wall box. You might have to trim some of the conductive part off to stop that.

If everything looks tight and there are no visible burns, the outlet might be damaged and needs to be replaced.

And if you're not comfortable at all doing that stuff, call an electrician. Figuring that out should be about an hour to an hour and a half of labor.
 

garsh

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Good advice from both @Needsdecaf and @Jason F .
I just want to provide responses to two other statements from the OP:
I took a video but this site won't let me upload it.
I suggest uploading your video to YouTube.
Then just include the YouTube URL in a post - it will automatically become embedded in the post.

Is the car pulling too much energy with the HVAC at full blast?
No. The Mobile Connector won't allow the car to pull more than 40 amps on a 50 amp circuit. If the car actually needs more power to run the HVAC, then it ends up using battery power.

As the others have said, it sounds like you have a bad connection somewhere in the vicinity of your outlet.

One other thing to check is where the NEMA 14-50 adapter plugs into the Mobile Connector. After unplugging from the outlet, pull the adapter apart from the Mobile Connector, then re-seat it FIRMLY. It takes a good bit of effort to seat it completely - make sure it's pushed in the whole way.
 
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gary in NY

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Either the wires are loose at the screw terminals behind the 14-50 outlet, or the 14-50 outlet has failed.

While you have the breaker off, remove the 14-50 outlet from the wall and check for loose screws. If the wires or outlet are burned, you're going to have to re-trim the wires and/or replace the outlet, or it won't be able to conduct efficiently and will heat up. Also look for burns on the wall box, it's possible too much insulation was trimmed and it's arcing against the wall box. You might have to trim some of the conductive part off to stop that.

If everything looks tight and there are no visible burns, the outlet might be damaged and needs to be replaced.

And if you're not comfortable at all doing that stuff, call an electrician. Figuring that out should be about an hour to an hour and a half of labor.
This ^^

I installed a HPWC, and found that I had to go back and retighten the screws. Although they were tight at the install, they needed to be torqued about a month later. (The heads up on this came from my local owners group where a member had his unit fail due to electrical arcing inside the box-from loose screws)
 
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Carl_P

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1. Loose connection between the EVSE (box with the Tesla lights) and the plug head.
2. More likely, connections have loosened at the socket. Have an electrician check it out.
3. Least likely, your EVSE has failed.

Call an electrician.

Thank you all for the thoughts. Wanted to give an update on this:

I had an electrician come (the same guy that installed it). When he opened up the outlet, it was clear there was some melting of wire that had happened, as well as some burn marks on the outlet itself. However, he noted that the connection at the socket was NOT loose. He still replaced the entire outlet.

HOWEVER, after replacement of the outlet, while the charger was no longer making that crackling sound, the charging cable and EVSE were still heating up pretty good while charging. We measured temperature with a heat gun and the point of EVSE connection to the 14-50 plug head was measuring 110 degrees after charging for a bit. Also, the charging cord itself was getting somewhat hot.

He didn't like this, and thought I should contact Tesla. So I am, and I have service coming tomorrow.

Do you think I need a new charging cable and EVSE, a new 14-50 plug head, or both?
 

garsh

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He didn't like this, and thought I should contact Tesla. So I am, and I have service coming tomorrow.
Good. Be sure to have the car at a low enough state-of-charge so that you can show the Mobile Connector in operation and reproduce the excessive heating.
Tesla should be able to figure out what parts need to be replaced.
 

JWardell

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Thank you all for the thoughts. Wanted to give an update on this:

I had an electrician come (the same guy that installed it). When he opened up the outlet, it was clear there was some melting of wire that had happened, as well as some burn marks on the outlet itself. However, he noted that the connection at the socket was NOT loose. He still replaced the entire outlet.

HOWEVER, after replacement of the outlet, while the charger was no longer making that crackling sound, the charging cable and EVSE were still heating up pretty good while charging. We measured temperature with a heat gun and the point of EVSE connection to the 14-50 plug head was measuring 110 degrees after charging for a bit. Also, the charging cord itself was getting somewhat hot.

He didn't like this, and thought I should contact Tesla. So I am, and I have service coming tomorrow.

Do you think I need a new charging cable and EVSE, a new 14-50 plug head, or both?

110F isn't anything to worry about, the cable and charger will get warm at higher currents normally.
Things don't start melting till over 500F.
 
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garsh

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110F isn't anything to worry about, the cable and charger will get warm at higher currents normally.
Things don't start melting till over 500F.
I wasn't sure if 110° F was high. I thought 80s was more normal.

But I also heard of another person having their mobile connector replaced because it was reaching 170° F. So I wasn't sure where 110° F ends up on the spectrum of OK to TOO HOT. :)
 

pikeman

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I hope you’re not using those cheap-ass $30 receptacles. Spend the money for the good one, I paid about $59 for mine. Hopefully the electrician advised on this matter.
 
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Carl_P

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Tesla came and replaced the charger cord AND 14-50 connector, and everything seems to be NOT getting hot now, even after a decent amount of time charging. It appears something was loose somewhere inside my cord, or at the connection between the EVSE and the 14-50 connector. He didn't diagnose the problem, just replaced. I was thankful! Good service with no questions asked haha (although I'd love to know how to prevent this from happening again).
 
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JasonF

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Tesla came and replaced the charger cord AND 14-50 connector, and everything seems to be NOT getting hot now, even after a decent amount of time charging. It appears something was loose somewhere inside my cord, or at the connection between the EVSE and the 14-50 connector. He didn't diagnose the problem, just replaced. I was thankful! Good service with no questions asked haha (although I'd love to know how to prevent this from happening again).

Not much you can do, really, it sounds like it was a manufacturing defect.
 

Carl_P

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Not much you can do, really, it sounds like it was a manufacturing defect.
I actually had a theory that I caused it by not bracing the EVSE (the little box at the end of the charger cord that says TESLA in green lights) against the wall at the outlet, and letting all of its weight pull down on the connection(s). Not an issue as a one-time thing but over three years, every day, could have possibly done it. Maybe?

For your at-home charging into wall sockets, do you brace or mount the EVSE at the end of your charger cord in any way? If not, have you had any problems long-term?
 

JasonF

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I actually had a theory that I caused it by not bracing the EVSE (the little box at the end of the charger cord that says TESLA in green lights) against the wall at the outlet, and letting all of its weight pull down on the connection(s). Not an issue as a one-time thing but over three years, every day, could have possibly done it. Maybe?

For your at-home charging into wall sockets, do you brace or mount the EVSE at the end of your charger cord in any way? If not, have you had any problems long-term?

I have one of these:

Amazon product
And one of these:

Amazon product
I also flipped over the 14-50 outlet so the cord goes downward instead of upward when plugged in.
 
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techzelle

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The problem was the cheap outlet the electrician put it. There was nothing wrong with the Tesla charger.
Likely the wires were not torqued correctly which is harder with those cheaper outlets. But they are not designed for continuous loads and are susceptible to fires.
Get the Hubbell 14-50 outlet, industrial quality, and recommended by Tesla. It's $80 vs the $10 ones at Home Depot.
This one is designed for heavy continuous loads, as well as repeated plugging and unplugging.
 
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garsh

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The problem was the cheap outlet the electrician put it. There was nothing wrong with the Tesla charger.
Given that replacing the mobile connector solved the problem, you would be incorrect.