Melted 240 outlet

[Bentleytn]

Newbie here and new to EV's.

I leased a bolt on a whim to use as a third car/grocery getter to reduce fuel from my big pick-up truck and just to check out electric. Loved it so much sold the truck and just rent one when I need it, wife loved it more and took the EV from me.....thats irrelevant to the topic, but should tell you who wears the pants in the family.

I had a 35 amp breaker (2) put in my panel, connected to a dryer outlet and used my buddies nissan leaf level 2 charging cord and for $60 set up worked fine for the first 10 months, then started noticing that the car seemed confused as to how long the charging would take, I would flip the breaker and all went back to working.

Then yesterday same thing, but I decided to hang in the garage to fiddle around and drink a glass of wine while looking at my former EV that my wife had confiscated. I noticed a sound and unplugged the charger, reset the breaker and then noticed it again, when I inspected the outlet it smelled and was hissing. I quickly disconnected and took the outlet apart and found the attached picture. Clearly overloaded or installed improperly. I know the gauge of the wire is large enough to handle and doesn't excessively heat (got that wrong originally) I do not know that I have big enough breakers or that the outlet is not defective or the wrong set-up. I know that the large continuous loads from the charging are more problematic and that set-up needs to be bullet-proof - don't know much more.

I'm curious if someone with some technical skills could tell me how I got this set-up wrong. Or give me some advice, i want to quickly fix it and have it working properly as I'm looking for another EV for myself. Would love to avoid getting a high end level 2 until my second EV arrives. Thanks for any help.

Man without an EV of his own.

 

[theothertom]

35 amp breaker? Code says to only use 80% of breaker amps for continuous use (like charging). So your max current should be 28 amps.
If the outlet worked ok for 10 months but recently caught fire, sounds like a connection worked loose. That can happen as wires heat and cool, expand and contract, and eventually work loose.

 

[Bolt2019]

Yes you'll need to know the power draw of that Leaf EVSE or if there's a switch on it.
The Bolt itself will take max 32 amps. So you'd need minimum 40 amp breaker with appropriate gauge cable for the length involved and that amperage.
(the system wants to make these links...I didn't)

 

[JoeS]

Photo? Which NEMA receptacle are you using?

 

[Bentleytn]

First off, thanks for sharing all of the expertise!

Here are pictures of the back of the charging cord, outlet and switches.

I don't know how it works as their are two 35amp breakers (does that equal 70 or is the measurement of capacity off of 35? Clearly I'm out of my pay grade) The cord (ESVE?) says 30 amp (80% would be 28 amps for just one of the breakers, which would suggest based on some of the experts suggestion that for continuous load I don't have enough) Don't know if this would cause the melting after 10 months after it working properly.

And the outlet is as pictured (I have the cover off of it to inspect)

Let me know any feedback if you have ideas for me. Thank you all so much.

 

[theothertom]

The pictures aren't showing but from your description, I'd say the total current available is 35 amps. So to meet code, you shouldn't use more than 80% of that, or 28 amps for your charger

 

[JoeS]

Bentleytn, in your PM to me you responded that the outlet was a NEMA 14-50 (!), that the circuit has two 35A circuit breakers, and you mention that the (portable?) Nissan Leaf EVSE is rated for 30A.

Sounds to me as though that EVSE has a NEMA 14-50 plug on it, which would be proper for a 30A draw.

However, earlier in this thread you also mentioned that "you had a 35A circuit breaker put in" and that you are using a "dryer outlet". Did you or someone also replace the dryer NEMA 14-30 outlet with NEMA 14-50 to match the connector on your Nissan Leaf EVSE?

First off, DO NOT TRY TO USE THIS RECEPTACLE UNTIL THE PROBLEM HAS BEEN IDENTIFIED AND A SOLUTION IMPLEMENTED. This is how houses burn down. Your Bolt can be quite happily charged on a daily basis using its own portable EVSE plugged into a plain old 120vac 15A wall outlet.

Unfortunately, we still can't see any photos and don't see any link within your posts.

A dryer outlet is normally NEMA 14-30. You must not just exchange its 30A circuit breakers with 35A circuit breakers, or replace a NEMA 14-30 receptacle with 14-50 receptacle without also addressing the wiring going between the breaker panel and this outlet (assuming the overall breaker panel capacity is sufficient to handle 50A).

First off, a 35A circuit breaker in each leg of the split-phase 240vac is still 35A (it is not additive). 35A is an unusual value, as a 14-50 outlet I would expect to have 50A circuit breakers. Again, are you sure the receptacle is 14-50 and not NEMA 14-30 (they look similar, but the Neutral prong on 14-30 has a bend to it)?

14-30 is what is normally installed for dryers, and the maximum continuous current you should be drawing from it is 24A.

Your Bolt will be trying to draw 30A, as instructed by that EVSE. Remember, your Bolt can draw up to 32A if an EVSE allows it to do that.

As others have pointed out, 80% of 35A is 28A which should be the maximum steady-state current you should be drawing from this circuit. Thus, your Nissan Leaf 30A EVSE is already telling your Bolt to draw too much current from this circuit.

That said, and with a 35A circuit breaker, I would not expect a "Melted 240 Outlet" as the NEMA 14-50 receptacle is easily capable of handling 40A continuously. I suspect that either the wiring inside the receptacle was not properly attached and/or the wires going from the circuit breakers to this outlet are undersized.

With the circuit breakers turned OFF, that receptacle needs to be opened up and examined, as well as the wiring going to it. If it has been subjected to heat stress, the receptacle needs to be replaced.

How long is the run from your circuit breaker panel to this receptacle? Depending on the wire type and its length, I would expect a wire size of #6AWG or #8AWG in there. Anything smaller (in physical size) is asking for trouble. Don't risk it!

Since the Bolt does not have onboard 240vac current adjustability, the only way to tell the car to reduce this current is inside that EVSE, and I don't believe that feature is adjustable on the Leaf portable EVSE (anyone?).

If you'd like to use this EVSE, it should be plugged into a circuit that contains circuit breakers AND wiring AND outlet that will handle 50A. NEMA 14-50 meets this need.

Enough food for thought - your best bet is to hire an electrician or ask a knowledgeable friend to help out.

If you want to continue using that "dryer outlet" and the wiring is undamaged, plan on using an EVSE with adjustable current so as not to draw more than 24A - I'd use 16A for a while and make sure nothing is getting warm before increasing the current.

Apologies for being repetitive, but overheating receptacles/wiring is one of the more common causes of house fires.

Let us know of your progress.

 

[Bentleytn]

Wow - I'm humbled by the time you took to help out.

To clarify the 14-50 plug is correct. I did not replace a dryer outlet, I incorrectly described it as a dryer outlet, it was a new install by an electrician. Clearly my guy was not super clear on what the needs were for the car, and I'll take the blame for that.

I agree it sounds like bad connections or wiring. I will have an electrician install new guage wire (I think its big enough but I don't know how to tell. It is about a 10-15 foot run from the breaker panel outside of the garage to the actual plug.

You are correct, the portable ESVE cable from the leaf is not adjustable so its drawing 30 amps (presumably)

The one thing I just don't understand is that the breaker panel has two 35 amp breakers (they are joined together by the "flip switch" How does that work - for example if my electrician was installing a 50 amp breaker is it two conjoined 25amp breakers or do they work somehow independently?

Again, thanks for all of your help!

 

[JoeS]

240vac in the North American split-phase system means that each 'leg' is 120vac and the two together form 240vac. Each leg has its own circuit breaker, which carries the full rated current. They are usually ganged and mounted together in the circuit breaker panel, so one flip opens/closes both legs.

Yes, have your electrician check the wire gauge to ensure it can handle the 50A that the NEMA 14-50 receptacle is rated for, and then increase the dual circuit breaker to 50A each. In your application, if the panel capacity is limited, you could use dual 40A circuit breakers because the maximum your Bolt could ever draw is 32A; however, the wiring must be sufficient to support this current.

As a matter of practice, I use EVSEs that have adjustable current and rarely find that I need to use more than 16A at 240vac in my everyday life. Less current is simply safer, especially in older houses with ancient wiring - and that applies to 120vac as well: I charged some of my EVs at 8A (instead of the maximum 12A) for years.