240 volt charging wall receptacle gets very warm 14-50R bryant

[DiveMan911]

Update on my overheating receptacle issue.
I opened up the outlet and I can’t tell exactly which size the THHN is, however it is solid copper and it’s either 12 or 10ga, so big enough for 30amps (edit…20amps). I tightened down the lugs. They were reasonably tight, but I really cranked them down. It was still warm. I basically determined this is likely an issue with the EVSE so I started troubleshooting it.
I opened up the EVSA itself with a plan to replace the wall side plug. It’s an early generation Lectron charger. What I found is disappointing. Although it’s a four wire (three conductor) plug (NEMA 14-30)…only 2 conductors are being utilized. Which I would imagine is what’s causing the heat. I’ll be finding a different EVSE.

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[TaxmanHog]

Update on my overheating receptacle issue.
I opened up the outlet and I can’t tell exactly which size the THHN is, however it is solid copper and it’s either 12 or 10ga, so big enough for 30amps. I tightened down the lugs. They were reasonably tight, but I really cranked them down. It was still warm. I basically determined this is likely an issue with the EVSE so I started troubleshooting it.
I opened up the EVSA itself with a plan to replace the wall side plug. It’s an early generation Lectron charger. What I found is disappointing. Although it’s a four wire (three conductor) plug (NEMA 14-30)…only 2 conductors are being utilized. Which I would imagine is what’s causing the heat. I’ll be finding a different EVSE.

The ground was not used?
Only the two HOTs were connected?

 

[Whammy Bar]

Update on my overheating receptacle issue.
I opened up the outlet and I can’t tell exactly which size the THHN is, however it is solid copper and it’s either 12 or 10ga, so big enough for 30amps. I tightened down the lugs. They were reasonably tight, but I really cranked them down. It was still warm. I basically determined this is likely an issue with the EVSE so I started troubleshooting it.
I opened up the EVSA itself with a plan to replace the wall side plug. It’s an early generation Lectron charger. What I found is disappointing. Although it’s a four wire (three conductor) plug (NEMA 14-30)…only 2 conductors are being utilized. Which I would imagine is what’s causing the heat. I’ll be finding a different EVSE.

Conductors need to be sized for continuous load. So if you're rocking yellow romex (12ga) your limits 16A. If you have the Halloween orange (10ga) then your limited to 24A.

 

[DiveMan911]

The ground was not used?
Only the two HOTs were connected?

1 hot, the neural and the ground.

 

[TaxmanHog]

1 hot, 1 neural and the ground.

Is this a 120 v circuit?

 

[TaxmanHog]

Sorry, I'm confused................. two discussion on this thread.

 

[DiveMan911]

Conductors need to be sized for continuous load. So if you're rocking yellow romex (12ga) your limits 16A. If you have the Halloween orange (10ga) then your limited to 24A.

It’s not Romex, it’s THHN in conduit. Conductors are wrapped in electrical tape identifying them, so I can’t read their size. I also don’t have a guage tool, so I was eyeballing it. Basically, an exact science. It’s definitely big enough for a 20 amp breaker, just seems silly they did a 20amp breaker on a 30amp receptacle.

 

[DiveMan911]

Is this a 120 v circuit?

No, 240V. The receptacle is a NEMA 14-30 with 3 conductors (2 hots and a neutral, plus the ground).

 

[chl]

Dielectric grease is an insulator, not a conductor. There is no manufacture that recommends usage of any grease or lubricant on lugs. In fact the torque specs for typical commercial 14-50 outlets made by Hubbell and Bryant are Dry Torque Specs.

The only wire connections that should have a chemical at the lugs are when using aluminum wires on lugs certified for aluminum. Then usage of something like NOALOX anti-Oxidant compound is REQUIRED. This is usually found on service entrance aluminum feeder cables.

Yes, dielectric grease if applied to protect against corrosion should be applied only after the terminal/wire contact is torqued properly. So for example, it is applied to the exposed parts of car battery connections AFTER they have been mounted and tightened.

See for example:

If the outlet is located in an area that is subject to moisture formation, then using a weather-resistant outlet box type is a must to prevent corrosion, and your local code may require it in garages.

 

[chl]

thanks Brons2. my EVSE (in the pic) was also a Amazon cheapie bought in 2020 for our PHEV Pacifica. The cheapie HD 14-50R outlet lasted 3 years before melting.

With the Lightning needing longer charging and up to the max 32A the EVSE is able to provide, I changed the cheapie outlet for the Bryant, but I guess I need to replace the romex as well and maybe the breaker - here in Florida its hot and humid, the circuit breaker panel inside the garage is showing signs of corrosion on the bus bars (where the breaker connection is seated. Perhaps I need to turn off the main and lightly sand the bus bars prior to installing a new breaker and wiring - but I must be getting old it was tough running the wire into the receptacle box and connecting the Bryant 14-50R and then getting the receptacle into the box once connected.

Sanding could/would create pitting which is a bad thing for electrical connections.

There is contact cleaner you can use if needed.

However, you should use a weather tight panel in your area of high humidity.

BTW, overheating can be mistaken for corrosion, both can caused a 'brown' discoloration of plastic parts in outlets in my experience. Of course corrosion can cause hot spots and overheating.

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