NEMA 14-50 meltdown

Was it permanently plugged in?

 

Wow, impressive. Wouldn't expect that.

 

And I thought I had a bad day when the coffee maker shorted out this morning..

 

I think the reason is printed right on it. Next time, Leviton or Hubbell, and be liberal with the DeOxit.

_H*

 

Makes me feel better about having to hardwire my home EVSE due to electrical regulations (all 240 V outlets require GFCI in my state).

 

You also might consider replacing it with a industrial version. Commercial receptacles may not handle high current draw for sustained periods of time as well. If you got the receptacle from a local big box hardware store you can probably assume it's commercial not industrial grade. An electrical supply house will have the larger industrial version. They are physically larger in diameter.

Cooper/Eaton 5745N or Hubbell HBL9450A are examples the industrial receptacles. An Industrial grade outlet will have a larger face which requires a receptacle cover with a 2.48" ID hole. (Mulberry 97223)

They are also considerably more expensive.

 

After a screw is tightened down on copper, the copper tends to "creep" and make things just
a little looser. When tightening fittings like that I always hold the final torque for a while longer,
and it usually snugs down a little more in the process. Wiggling tne wire if possible and giving
every screw one more little squeeze before buttoning things up is a good idea.

Also note how the female spring contacts in several of these aren't full blade height...

_H*

 

How frequently does the plug gets in and out the receptacle as they might not be designed for this kind of service use?
Is this installed at your workplace with frequent in-outs?
Do you have to bring your own EVSE and take it out after use?
If so, are the other EVSE plugs corroded?
Compare with the designed maximum number of insertions directly from the supplier or specs sheet. This number of plug-in, plug-outs is much lower than people think and the same problem is frequent with L1 120 V EVSE « emergency unit » that comes with the car.
The one given with Rav4 Prime even has a built-in counter to give a «replace EVSE» alarm to minimize overheating like you got.
That is the main reason to wire permanently in the supply cable and not use a convenience plug-receptacle system.

Sent from my iPhone using Inside EVs

 

Having acquired a second phev, I'm finally looking to install L2 and came across the Leviton offering. They state that GFCI is required for the WR version, so I'm staying away from that one based on user reports of nuisance trips from independent GFCI (and other user reports that 2023 NEC allows the GFCI functionality to be provided by the EVSE). Here's the info page with links to pdfs:
https://www.leviton.com/en/products/1450r

 

The latest National Electrical Code requires a GFI breaker if you use a plug/receptacle. Not every jurisdiction follows the latest National Electric Code, so whether a GFI breaker is required depends on where you live. You can always hardwire your EVSE, and that doesn't require a GFI breaker to meet the National Electrical Code.

I suspect the GFI requirement has less to due with just an EVSE, and more likely due to the receptacle being available to any other device to could get plugged into the receptacle, hence an EVSE doesn't need a GIF breaker for a hardwired EVSE.

You can read the National Electrical Code for free if you sign up for a free account.

https://www.nfpa.org/codes-and-standards/7/0/70?l=109

 

This is not the first report of this I have seen online. I believe the issues is in fact residential quality parts used continuously at the full load. NEMA 14-50 may be rated for 50 amps FLA, but the service is only 40 amps. The chargers know this of course.

I use a 14-30 (dryer) plug which is rated for 24 amps of service. However I dial down the charger to 20 amps for additional safety as I charge overnight. For what it is worth, I would say if you don't need the speed of 40 amps (I don't), I would lower the draw. You can always amp it up if your in a hurry.
25 amps is about 22 miles of charge per hour - plenty for an overnight charge.