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PSA. Another melted NEMA 14-50 receptacle

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Just a reminder to make sure the UMC is snug when plugging into the outlet.
There shouldn't be any play when plugged in. If you don't have the Tesla recommended NEMA 14-50, (Hubbell/Cooper), minimize plugging and unplugging the UMC.

This outlet was installed about a year ago, the loose connection between the adapter blade and the outlet caused the adapter to melt into the receptacle. The circuit breaker save the day.

Hope this helps someone.
 

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I recently installed NEMA 14-50 in my garage, and garage is under my living room. Waiting for delivery (Sep18-Nov18) to try it out. Will check often for any signs of burning. To make circuit breaker save the day there should be overload, short circuit for example. The danger is that the melting happened because of the bad contact while current is still below 50A.
 
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Just a reminder to make sure the UMC is snug when plugging into the outlet.
There shouldn't be any play when plugged in. If you don't have the Tesla recommended NEMA 14-50, (Hubbell/Cooper), minimize plugging and unplugging the UMC.

This outlet was installed about a year ago, the loose connection between the adapter blade and the outlet caused the adapter to melt into the receptacle. The circuit breaker save the day.

Hope this helps someone.

That's weird. Did you get any charging errors from your car? The car should be able to sense a problem as a drop in voltage and stop charging. It's unlikely your circuit breaker was much help since as @BestHand mentioned a circuit breaker only trips if current exceeds its rating. If you have a high resistance connection it doesn't take much current to melt the outlet...
 
minimize plugging and unplugging the UMC.

Thanks for the post.

I'd say that the above is really important.
Everybody who gets a plug-in should have a dedicated EVSE for home charging, whether plug-and-socket or hard-wired, and then have a portable.

A UMC bundle is $300. That's cheap, even for a 32A EVSE.
 
Thanks for the post.

I'd say that the above is really important.
Everybody who gets a plug-in should have a dedicated EVSE for home charging, whether plug-and-socket or hard-wired, and then have a portable.

A UMC bundle is $300. That's cheap, even for a 32A EVSE.
Most people have no need for both. You only need to take the UMC with you on out of town trips. Leave it plugged in at home otherwise.
 
Most people have no need for both. You only need to take the UMC with you on out of town trips. Leave it plugged in at home otherwise.

For $300 you essentially eliminate the risks from socket wear or not securing the plug, you always have your portable EVSE with you, and you have a back-up if your primary EVSE fails.

To me it's a combination of safety, insurance and convenience and worth the relatively small one-time payment. People pay more every year for cellphone convenience.
 
Just went and checked mine. Had a Tesla recommended electrician install mine and it says Cooper on it. Also went online and see that Leviton sells for a fraction of the Cooper outlets.
Wonder if this failure was the outlet, or the wire not being tight when installed?
 
Just a reminder to make sure the UMC is snug when plugging into the outlet.
There shouldn't be any play when plugged in. If you don't have the Tesla recommended NEMA 14-50, (Hubbell/Cooper), minimize plugging and unplugging the UMC.

This outlet was installed about a year ago, the loose connection between the adapter blade and the outlet caused the adapter to melt into the receptacle. The circuit breaker save the day.

Hope this helps someone.

Wow, thank goodness that did not result in a house fire!

I wonder if the circuit breaker saving the day was because it eventually shorted hot to ground or to neutral or to the other phase and that blew the breaker?

Was perhaps the UMC not plugged in all the way perhaps and just making slight contact?

Was this a UMC Gen 1 or UMC Gen 2? I would think the heat sensing in the new UMC Gen 2 should have caught that and stopped charging?
 
Wow, thank goodness that did not result in a house fire!

I wonder if the circuit breaker saving the day was because it eventually shorted hot to ground or to neutral or to the other phase and that blew the breaker? Yes

Was perhaps the UMC not plugged in all the way perhaps and just making slight contact?
Loose connection between the socket and the blade, caused arching, then melted

Was this a UMC Gen 1 or UMC Gen 2? I would think the heat sensing in the new UMC Gen 2 should have caught that and stopped charging?
Gen 1
It now take some effort to plug the 14-50 adapter to the receptacle, tight fit.
 
Gen 1
It now take some effort to plug the 14-50 adapter to the receptacle, tight fit.

Are you saying you put in a Cooper of Hubbell receptacle now and it is much stiffer? Which did you go with?

The UMC Gen 1 makes sense. It draws a full 40a vs 32a and it does not have a temp probe like the Gen 2 does.

Do you think the issue was the wire not being torqued properly down? Or was the UMC not inserted all the way fully? Or do you think it was some other internal failure of the receptacle?

These are dangerous failures and so I think as a community we need to understand how they happen. That is good data for fire inspectors btw...
 
Are you saying you put in a Cooper of Hubbell receptacle now and it is much stiffer? Which did you go with?

The UMC Gen 1 makes sense. It draws a full 40a vs 32a and it does not have a temp probe like the Gen 2 does.

Do you think the issue was the wire not being torqued properly down? Or was the UMC not inserted all the way fully? Or do you think it was some other internal failure of the receptacle?

These are dangerous failures and so I think as a community we need to understand how they happen. That is good data for fire inspectors btw...
Probably caused by repeated plugging and unplugging, MS is over a year old.
Levitton, didn't know about the Hubbell and Cooper brands. The original electrician replaced for free the receptacle and replaced the 50 amp GFCI breaker with a non GFCI as recommended by Tesla. Was causing the breaker to trip, 2 GFCI in a series.
 
Probably caused by repeated plugging and unplugging, MS is over a year old.
Levitton, didn't know about the Hubbell and Cooper brands. The original electrician replaced for free the receptacle and replaced the 50 amp GFCI breaker with a non GFCI as recommended by Tesla. Was causing the breaker to trip, 2 GFCI in a series.

Ah, so do you plug and unplug it every day then?

Note that downgrading to a non GFCI breaker is now a code violation in 2017 NEC article 625.

Though if it was a non-wet location I totally am in the no-gfci breaker camp.

The new rule is not well known by most inspectors and is commonly not enforced.
 
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Did my own set up inside the garage and used 6 gauge wire with Hubble NEMA 14-50. In addition bought the NEMA 14-50 plug adapter for my Gen 1 mobile charger. Leave the adapter plugged in all the time. Plug and unplug the mobile charger. Used a Cooper at our second home with 6 gauge wire. Don't use it as often so plug and unplug from the receptacle. Difference is the Hubble posts are brass coated steel. Just bought another Gen 1 MC. Leave one at home and keep the other in the car.
 
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I bought the Hubbel 14-50 for first install. Receptacle tabs are brass coated steel. As I recall was about $60 at local Electrical supply outlet. Have had no issues with it. Installed a Leviton 14-50 at our vacation home from Home Depot for $7. Bare steel resepticle tabs. No issues. It is important to use the 6 gauge wire from breaker panel to outlet. Won't get any heat build up except at Tesla adaptor and cord. From size of cord probably 8 gauge at most. Cord gets warm. I see no real difference between the Hubbel and Leviton outlets, except the shiney brass coating
 
HI all,
Glad I found this forum. I too have a melted outlet. I had a licensed electrician install this years ago. Didn't have any issues until recently. We reach the cord about 10 feet to plug into the car, so I believe that over time, the plug started to wiggle out of the outlet, and/or weakened the contacts inside the outlet with the sideways torque that just the weight of the cord was putting on it. When I noticed it, the plug was slightly out of outlet. Sometimes the cord gets a little tangled and it's likely that we added some torque pulling on it. As you can see from the pictures, this was a close call. The breaker never tripped and the car gave no indication that there was something wrong. I leave the cable plugged in 100% of the time. Since we bought the car years ago, I'll assume that I have the gen 1 UMC.
I'll be making sure that I have a GFCI breaker and the recommended brand of connector this time. Replacing the box too with a properly mounted box. Will probably buy a new UMC too, just to be safe.
 

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