Shocked My Hubbell 14-50 Failed!

[Cbowe]

I knew better… and yet ….

After 4 years of EV charging, my setup finally failed. If you’re using a NEMA 14-50, you’ll want to see what my procrastination caused. It can happen to you 🫵

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[I <3 My Lightning]

Based on your video you show your so called damaged hubble around ~5:30 mins. It looks nothing like your video image.

Did you even call hubble or take it apart to see if there was any internal damage or just bugs?

 

[Cbowe]

Based on your video you show your so called damaged hubble around ~5:30 mins. It looks nothing like your video image.

Did you even call hubble or take it apart to see if there was any internal damage or just bugs?

The thumbnail is just a thumbnail there also weren’t any lightning bolts coming from it either lol

it was actually bizarrely normal looking and at first glance no indication of any problems at all. This all happened this morning so haven’t done anything with it yet. I didn’t know Hubbell would take them back. I would be very curious what they would find. Have you heard that they will do that?

 

[I <3 My Lightning]

Ask them or simply take off the back. There should be a single screw/hex in the middle of the back.

That outlet is uL tested and certified for a continuous 50 amps at 250v. That is not a typo. It's rated and tested for up to a continuous 12,500 watts. It accepts up to 4 gauge copper. Of course with electric code you are not to exceed 40 amps on a 50 amp breaker for ev charging when using a 14-50 outlet.

If you are guilty of anything is that you didn't check the torque of the lugs yearly. A continuous 40 amps through that thing is childs play.

 

[Maquis]

Open ground internal to a receptacle is a really unusual failure mode. Did you take an ohm reading from the ground terminal screw on the back to the ground pin on the front? Also from each of those points to the mounting flange?

 

[Cbowe]

Ask them or simply take off the back. There should be a single screw/hex in the middle of the back.

That outlet is uL tested and certified for a continuous 50 amps at 250v. That is not a typo. It's rated and tested for up to a continuous 12,500 watts. It accepts up to 4 gauge copper. Of course with electric code you are not to exceed 40 amps on a 50 amp breaker for ev charging when using a 14-50 outlet.

If you are guilty of anything is that you didn't check the torque of the lugs yearly. A continuous 40 amps through that thing is childs play.

Definitely never checked the torque of the lugs

 

[Cbowe]

Open ground internal to a receptacle is a really unusual failure mode. Did you take an ohm reading from the ground terminal screw on the back to the ground pin on the front? Also from each of those points to the mounting flange?

I’m going to take some meter readings tomorrow and see what I get. I’m at work now but I’ve had some folks curious about that so I’ll see if anything stands out.

 

[Cbowe]

Open ground internal to a receptacle is a really unusual failure mode. Did you take an ohm reading from the ground terminal screw on the back to the ground pin on the front? Also from each of those points to the mounting flange?

Here is a follow up testing the Hubbell outlet check out how strange this failure was

I’ve Never Seen a Hubbell NEMA 14-50 Fail Like This!

 

[chriserx]

Curious, you talked about testing on the blades, with it plugged in have you tried testing the continuity on the contacts? They obviously move when plugged in, could they be dirty or cooked and no longer able to make contact with the prong, or does the movement otherwise physically disconnect the ground ?

 

[Cbowe]

I might open up the outlet and see what is going on inside. I’m not too sure internally what happens when the plug is pushed in to the outlet if anything is damaged internally or being separated but the way it works when unplugged again just seems so odd like it springs back and makes the electrical connection again.

 

[chriserx]

Actually, do the continuity, just touching the plug as you slide it in, that could give you your answer.

 

[Cbowe]

I can’t really put both the probe and plug in at the same time I don’t think it would be in the way.

 

[chriserx]

No I meant the prong, just touching it with the probe and the other end at the ground, it should have continuity, as you slide, continuity should be broken as you slide, the point at which could reveal some answers.

 

[Maquis]

Here is a follow up testing the Hubbell outlet check out how strange this failure was

I’ve Never Seen a Hubbell NEMA 14-50 Fail Like This!

Wow….that’s bizarre. I take from looking at your installation that you don’t plug/unplug often, which takes fatigue failure out of the equation. The root cause must be some manufacturing defect that caused some internal pathway to break open after some time period.

Thanks for taking time to investigate deeper!

 

[Dan C]

A good argument for hard wiring. If you do need to plug and unplug often you will see more failures in the receptical

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