Melted 240V outlet (Major Disaster Avoided) -- PSA: only highly rated charging equipment

[Maquis]

The wire interface points on my 6-50 look like those in the 4th picture. This is extremely important because a direct screw interface such as in the third picture is more prone to heating up and therefore losing torque. My 6-50 has been there since 2014. I used to check the torque on the screws semi-annually, then annually. Now I just check whenever the whim hits me since there has been no measurable change in torque. ??

Even though the UL listing says otherwise, I consider the terminals where the screw directly contacts the conductor as suitable for solid wire only - the twisting action mashes stranded wire, pushing some of the strands out of the compression area.

After 10 years, I’d say you’re good to go!

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[dtbaker61]

It's been over 3 years, but if memory serves it was 40 amps. It's possible it was set at 32. But I'd generally get 9kw flowing.

if you were generally seeing 9kw, you likely had the charger set to 38 or 40amps, which is too much for a NEMA14-50.

 

[ChasingCoral]

if you were generally seeing 9kw, you likely had the charger set to 38 or 40amps, which is too much for a NEMA14-50.

A 40A charger is the maximum allowable on a 50A circuit. A properly installed and maintained commercial-grade 14-50 outlet on a 50A circuit with the proper wire size should be just fine to power a charger up to 40A.

That said, I would always hardwire a charger for regular use in my own home.

 

[dtbaker61]

A 40A charger is the maximum allowable on a 50A circuit. A properly installed and maintained commercial-grade 14-50 outlet on a 50A circuit with the proper wire size should be just fine to power a charger up to 40A.

That said, I would always hardwire a charger for regular use in my own home.

risk goes up with currents over 32amps, even in a perfect installation with low ambient temperatures.

The point is unless you REALLY need a 9kw charge rather than a 6kw charge at home.... you will be safer to limit charge to 32amps on a 50amp circuit whether you use a plug or hard-wire.

 

[ChasingCoral]

risk goes up with currents over 32amps, even in a perfect installation with low ambient temperatures.

The point is unless you REALLY need a 9kw charge rather than a 6kw charge at home.... you will be safer to limit charge to 32amps on a 50amp circuit whether you use a plug or hard-wire.

Lower loads are always safer and more reliable than higher loads.

 

[azerik]

Cheap Leviton NEMA 14-50 outlet strikes again...

Everybody should check that they don't have one of these junk Leviton outlets. They're notorious for this. They've very common, and hundreds have melted this way during EV charging.

Headed back to home depot.. lol

 

[shutterbug]

The ones you want will say Industrial or Commercial grade on the box. Some say designed for EVs. Also, if it’s less than $20 you don’t want it. You want the ones that are $50-100.

I get it, but what exactly is the advantage?

 

[HuntingPudel]

I get it, but what exactly is the advantage?

The advantage in an Industrial or EV-grade receptacle is in how it’s constructed and designed. The landing points for the conductors are designed to clamp the wiring rather than just screwing the bare end of a screw into it. The interfaces between the socket and prongs are set up to make a higher quality connection. The insulation material can handle higher temperatures and tends to have a higher dielectric constant. A commercial or residential grade outlet can handle low duty cycles. An industrial or EV outlet can handle the load over a long time. ??

 

[shutterbug]

The advantage in an Industrial or EV-grade receptacle is in how it’s constructed and designed. The landing points for the conductors are designed to clamp the wiring rather than just screwing the bare end of a screw into it. The interfaces between the socket and prongs are set up to make a higher quality connection. The insulation material can handle higher temperatures and tends to have a higher dielectric constant. A commercial or residential grade outlet can handle low duty cycles. An industrial or EV outlet can handle the load over a long time. ??

How is that an advantage over hard-wired? I should have been more explicit.

 

[HuntingPudel]

How is that an advantage over hard-wired? I should have been more explicit.

It’s not. Since this thread is about an outlet receptacle I have been responding in kind. ?‍?

 

[ChasingCoral]

How is that an advantage over hard-wired? I should have been more explicit.

It’s not. It’s an advantage over cheap outlets.

 

[ChasingCoral]

The advantage in an Industrial or EV-grade receptacle is in how it’s constructed and designed. The landing points for the conductors are designed to clamp the wiring rather than just screwing the bare end of a screw into it. The interfaces between the socket and prongs are set up to make a higher quality connection. The insulation material can handle higher temperatures and tends to have a higher dielectric constant. A commercial or residential grade outlet can handle low duty cycles. An industrial or EV outlet can handle the load over a long time. ??

Also, the really cheap outlets like some Levitons have contracts that only cover half the length of the plug blades.

 

[Maquis]

Also, the really cheap outlets like some Levitons have contracts that only cover half the length of the plug blades.

Pictured in post 15.

 

[woody]

I guess. However, most of us can't tell the difference between "industrial" and "commercial". What we can tell is that there is no advantage to plugin connection. I'm sure someone will bring up the "what if I want to move and take my charger with me" argument. But that will be years from now and the cost difference will be minimal ($50-$100 on top of running a new connection) and may not even happen before you need a new charger.

of course there are advantages to (properly installed) plugin connections

 

[devmach-e]

if you were generally seeing 9kw, you likely had the charger set to 38 or 40amps, which is too much for a NEMA14-50.

40A on a 50A circuit is perfectly fine. In fact, it conforms to the NEC, assuming the correct gauge wiring was ran, a heavy duty outlet was used, like the Hubbel or Bryant, and connections were properly torqued. Too much for a NEMA 14-50 would be 48A continuous use.

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