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

[sdan45]

I've got the electrician coming out after work tmw. Hoping they can just hardwire the unit (assuming the unit is sitll operational).

Good for you for calling in an electrician. I've been doing electrical work for 44 years and am mostly retired right now. I've got several Ford dealerships that I do work for and have install many Ford charging stations that are all hardwired. I've installed many chargers for home use and have always hardwired those too. Hardwired is the way to go. The less connections between the breaker and the appliance the better.

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[devmach-e]

Look up wire size ampacity rating tables and then read the fine print on hours of continuous use.

It is not in residential NEC because they never considered 5 or 10 hours of continuous use before EV came along.

Sure in a perfectly installed system you can probably run 40 amps for several hours without any problems, but I think it is irresponsible to suggest that there is not higher risk and it is advisable to stick to 32 amps or 36 at most for a reliable and safe installation

Continuous duty is 3 hours or more, not 5 or 10 hours. The specific NEC rule is:

Article 100 Definition: Continuous Load: A load where the maximum current is expected to continue for 3 hours or more.

210.20(A) Continuous and Noncontinuous Loads. "Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less than the noncontinuous load plus 125% of the continuous load."

Breaker (overcurrent device) has to be matched to the wiring. So the ampacity of the wiring for the circuit has already been increased to 125% of the EVSE's capabilities. I.e I have a 32A EVSE, I have to have a circuit breaker and wiring that rated for 40A. If I have a 14-50 or 6-50 outlet, and it has been wired with the appropriate sized wiring and breaker, the maximum amperage that the EVSE is supposed to pull is 40A.

 

[Scooby24]

And they are?

Here's an example:

I have an OPENEVSE unit and the relay welded shut...I had to open it up and swap out the relay. I had to order the relay as it couldn't be used while it was welded shut and the local Grainger didn't carry this specific relay.

Was able to just unplug the unit, and plug in my mobile charger to use temporarily. If I had hardwired my unit, I'd be charging on 120v for a week while I waited for a part in the mail.

I've seen lots and lots of failure threads and every single one has been a commercial grade outlet. I've not seen or heard a single instance of the industrial outlets failing....and as such see no benefit to me personally to hardwire. Maybe when bidirectional charging is more common then I'll reconsider.

 

[devmach-e]

Resetting is just as easily accomplished by turning off and on of the breaker. As to swapping the units (for whatever reason) involves minimal cost to have an electrician do it, and it doesn't happen all that often (unless you have a plug-in unit, of course).

Breaker may not be nearby or convenient to get to, especially if you have to do something within a certain time period when power is reset. When swapping the unit you can't always wait for an electrician to show up. Failures of EVSE's always happen at an inopportune time.

I have a hardwired unit. It was originally a 30A unit with 16-foot cord. I swapped it for a 32A unit with a 25-foot cord. It took a significant amount of time to do so, even though they were the same physical unit, so essentially plug and play. A plug-in version would've take a lot less time.

 

[67 Stang Convertible]

Here's an example:
Maybe when bidirectional charging is more common then I'll reconsider.

Speaking of Bidirectional charging......I stumbled across this when I was considering a new charger.

https://www.emporiaenergy.com/how-the-emporia-v2x-charger-works/

 

[devmach-e]

Speaking of Bidirectional charging......I stumbled across this when I was considering a new charger.

https://www.emporiaenergy.com/how-the-emporia-v2x-charger-works/

Sadly, the Mach-E isn't setup for V2X(home, grid, load). But if you get a Lightning, it might be a viable alternative to Ford's solution.

 

[dtbaker61]

Sadly, the Mach-E isn't setup for V2X(home, grid, load). But if you get a Lightning, it might be a viable alternative to Ford's solution.

The Mach-e is not set up internally for bi-directional charger... but you CAN export up 1500-2000watts via 12v connection points and run it thru an inexpensive (<$400) to run whatever you want.

My MME is my backup Generator for emergency power.... Enough energy with a full battery to run all my critical loads for 6+ days. This is why I like to have the 240v outlet rather than hard-wire my charger.

 

[dtbaker61]

I have two EVSE's in the garage and another 240v outlet. Both my EVSE's are hard-wired.

But even hard-wire can be a problem if the installer does SERIOUSLY tighten down the lugs. When I did my install, we added wire ferrules and picked up the appropriate tool (4 jaws "square" the end of the wire inside the ferrule) and this gives a nice flat contact surface for a better connection.

IF this isn't TIGHT then all the power has to flow through a minimally sized contact surface and that can create resistance which leads to heat which leads to ... what happened here.

As for the NEMA 14-50 Receptacle ... that has to be replaced and get an industrial outlet (it should cost in the $40-80 price range and have a brand name such as Hubbell. DO NOT buy a NEMA 14-50 R priced in the $10-20 price range. Those can't handle EV charging.

WHY: Most things that plug into a 240v outlet only draw power for limited amounts of time. Even an electric oven baking something for hours on end isn't actually CONTINUOUSLY drawing power. An oven pre-heats and then starts to cycle the heating element on/off periodically to maintain the temperature. Dryers to the same thing (and they don't draw 50 amps).

But an EV ... that can pull power continuously for 6-8 hours without ever letting up ... and that's a problem for ordinary 240v outlets.

If you DO want to use another receptacle (instead of going hard-wired ... but hopefully by now you've decided to go hard-wired) then you'll need a NEW outlet AND the plug on your EVSE must be SHINEY metal. There must be no charring or blackness. The char will create resistance and resistance causes heat and you'll risk having the whole nightmare all over again. You need thoroughly clean bright shiny metal.

exactly... to pull more than 32a requires a perfect install and high quality components and wire. If you have a cheap plug, outlet, or questionable wire, then stick to 32a MAX.

if your REALLY REALLY NEED a faster charge, then step up to new equipment and use a trusted licensed electrician.

 

[shutterbug]

I have an OPENEVSE unit and the relay welded shut

Sorry to hear this. How often does this happen with Open EVSE?

If I had hardwired my unit, I'd be charging on 120v for a week while I waited for a part in the mail.

Or...Use DC charging. Sort of an in-town road trip.

 

[shutterbug]

Breaker may not be nearby or convenient to get to, especially if you have to do something within a certain time period when power is reset. When swapping the unit you can't always wait for an electrician to show up. Failures of EVSE's always happen at an inopportune time.

I have a hardwired unit. It was originally a 30A unit with 16-foot cord. I swapped it for a 32A unit with a 25-foot cord. It took a significant amount of time to do so, even though they were the same physical unit, so essentially plug and play. A plug-in version would've take a lot less time.

So as part of this, did you switch to a plug-in unit?

 

[devmach-e]

So as part of this, did you switch to a plug-in unit?

I get what you are trying to imply here, that if I'm okay with plug-in units, why don't have one of my own? Because of various reasons, including the fact that when I had the original 30A unit installed some 12 years ago, only a hard-wire connection was available. Not to mention that it's mounted on the front of my garage in my driveway, so a 14-50 outlet wasn't practical. And if it weren't for the fact that the 32A unit was a drop-in replacement 7 years ago, I probably would still be struggling with the 30A unit and its short cord. I swapped in an essentially identical EVSE in. Same mounting hardware. Same wiring requirements. Just 2A more of charging and 9-more feet of cable. I got lucky that GM was selling a 32A version of the original Nissan 30A EVSE from AeroVironment.

Just because I don't have a plug-in EVSE doesn't mean I can't recognize why others might want one.

 

[Jerrytball]

I'd like to note that there are hardly any such disasters with hard-wired chargers.

??

 

[shutterbug]

I get what you are trying to imply here, that if I'm okay with plug-in units, why don't have one of my own? Because of various reasons, including the fact that when I had the original 30A unit installed some 12 years ago, only a hard-wire connection was available. Not to mention that it's mounted on the front of my garage in my driveway, so a 14-50 outlet wasn't practical. And if it weren't for the fact that the 32A unit was a drop-in replacement 7 years ago, I probably would still be struggling with the 30A unit and its short cord. I swapped in an essentially identical EVSE in. Same mounting hardware. Same wiring requirements. Just 2A more of charging and 9-more feet of cable. I got lucky that GM was selling a 32A version of the original Nissan 30A EVSE from AeroVironment.

Just because I don't have a plug-in EVSE doesn't mean I can't recognize why others might want one.

Ok, you are dealing with legacy install issues. But if you were getting a brand new EVSE and had a clear choice, would you opt for hard-wired or plug?

 

[devmach-e]

Ok, you are dealing with legacy install issues. But if you were getting a brand new EVSE and had a clear choice, would you opt for hard-wired or plug?

My install location (outside, attached to front of garage) doesn’t allow for a socket, so I have to go with a hard-wired solution no matter what. If Ford was paying for a new install in the garage, then a socket would be fine, but that assumes that I can park in the garage. Which I cannot do at this time. Or probably ever.

 

[Maquis]

Ok, you are dealing with legacy install issues. But if you were getting a brand new EVSE and had a clear choice, would you opt for hard-wired or plug?

Another consideration if you are under 2020 NEC or later is that a receptacle outlet requires GFCI protection. Hard-wired does not.

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