Burnt 240V outlet

[Ngkgb]

My misunderstanding, I thought you have 30A wires between the breaker box and the outlet (on the picture). I should have read more carefully.

If you have 50A wires (6AWG) between the box and the outlet then I was mistaken and you are right you can charge with 30A if the charger says it supports that continuously, mea culpa maxima.

To be fair my original post wasn’t 100% clear. Looks like I’ll be bringing in an electrician to hardwire a charger and review the whole installation.

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[Chrisy]

To be fair my original post wasn’t 100% clear. Looks like I’ll be bringing in an electrician to hardwire a charger and review the whole installation.

Make sure they check the wire gauge inside that conduit as well. Helps to sleep better to know you have 6AWG That conduit on your pic looks a bit skinny but who knows, looks like you might have a 2/1 for that outlet.

Some "electricians" just plop breakers in without considering that pulling a new wire might be necessary. Upgrading a circuit for EV charging is not simply swapping the breaker to a beefier one...

 

[Zoidz]

NGKB is correct about 40 amps (it's 80% of 50 amps). A charger is considered a continuous load and calls for the 80% rule (it's in the NEC). 42 won't fly within the code

lol, yes, 40A is correct. I'm quite familiar with NEC. Typing fast and not proofreading...

 

[R.I.P.]

Most mobile EVSEs on the market today are cheaply made "dumb" units that do not include heat and voltage sensing routines to protect the wiring, the EVSE and vehicle.

It is for this reason I recommend using the Tesla mobile EVSE and the NEMA kit for mobile/plug-in use. It will sense the heat caused by bad connections, low voltage and other conditions and automatically lower the draw from the wall to prevent damage; while at the same time throwing an error message to the user so the condition can be corrected without burning the house down.

Probably a good place to reinforce the following:

1. The Rivian mobile EVSE is not a good unit. If you plug in a lot at campgrounds and such, invest in a Tesla unit.

2. Avoid using third party plug adapters, as they have zero line sensing ability or error correction. Instead, use Tesla's nema kit to plug into any and all plugs.

 

[Ngkgb]

Thanks for all the input everyone. Just ordered the hardwired ChargeFlex. In case anyone is interested, i asked the bot on their website for a discount code and he gave me one for 10% off. ? Use code Drift10.

 

[SPITmadFIRE]

Other people can chime in, but I don’t believe this is correct. My breaker is 50 Amps and the charger is 30Amps. I believe the 80% rule is for picking the charger. For example the next charger I chose should be no more than 40 Amps. That’s my understanding.

The 80% rule is for every component from breaker to outlet, inclusive. That means your circuit is only safe to operate at 80% of the lowest rated component. If you have 8awg wire, 50A breaker, but an outlet that is only rated for 30A, then your max safe sustained load is 24A.

 

[Ngkgb]

The 80% rule is for every component from breaker to outlet, inclusive. That means your circuit is only safe to operate at 80% of the lowest rated component. If you have 8awg wire, 50A breaker, but an outlet that is only rated for 30A, then your max safe sustained load is 24A.

How do I know what the outlet is rated? Why electricians make a 50 Amp breaker and only install a 30 Amp outlet?

 

[SPITmadFIRE]

How do I know what the outlet is rated? Why electricians make a 50 Amp breaker and only install a 30 Amp outlet?

That's a great question. If you specifically chose the outlet and asked the electrician to install it on a 50A circuit, that could explain why they did it. I don't recognize what type of outlet it is offhand, but it doesn't appear to be a 14-50 NEMA which would be a great choice for a 50A 240V circuit.

 

[SPITmadFIRE]

How do I know what the outlet is rated? Why electricians make a 50 Amp breaker and only install a 30 Amp outlet?

Judging by the lettering on the top of the outlet (the outlet was installed upside down), it appears to say "50A 250V" so I doubt it was the outlet choice that did it. Almost certainly a faulty connection as others have said

 

[Chris TX]

To be fair my original post wasn’t 100% clear. Looks like I’ll be bringing in an electrician to hardwire a charger and review the whole installation.

I used the Mobile Connector (charge cord) that came with my Tesla in 2013, for 10 years with no issues. I used a Leviton 14-50 outlet from Home Depot. The KEY is proper terminal torque, here.

 

[John Binford]

Recommend buy commercial grade, (Brand name plug) Electronic infrared thermometer, (check all the plus and breaker from RT! to 50 amp breaker. Strained copper wire works must be checked and inspected. I use the thermometer often. I check the cord for being crushed. Even if I had it direct wired, I still check due to long charging times. I even check the cloth dry, stove and A/C system. KiLL POWER TO MAIN SERVICE CHECK WITH METER BEFORE YOU DO THE TEST.

 

[Electrified Outdoors]

I agree with @R.I.P. on the mobile/portable units. They aren't really designed for daily use. Yes, there are some folks that use them for a long time with no problem but the outlet increases your chance to have a failure. I have a 40 amp mobile ShockFlo unit that I use on travel. It tells me line voltage and allows me to adjust amperage from 40amps down to 16 amps.

Voltage is important at campgrounds. A brownout won't make you popular with neighboring campers ?

Lastly, in the US if you install a hard wired EV charger you should be able to recoup some of your costs through a federal tax credit.

There are a lot of good points here about wire sizing etc. The last point I'll make is about having the work permitted and inspected. It gets an extra set of eyes on it to make sure the electrician isn't cutting corners and that the install is safe. Part of that process is also to notify the utility as well for capacity planning purposes.

I have Tesla Wall Connector on a 60 amp circuit, #6 90C THHN in conduit. I have seen quite a few of these melted outlets over the years and I am very passionate about EV charging safety. Hardwired is the way to go especially with large battery like in the Rivian.

 

[Ngkgb]

I agree with @R.I.P. on the mobile/portable units. They aren't really designed for daily use. Yes, there are some folks that use them for a long time with no problem but the outlet increases your chance to have a failure. I have a 40 amp mobile ShockFlo unit that I use on travel. It tells me line voltage and allows me to adjust amperage from 40amps down to 16 amps.

Voltage is important at campgrounds. A brownout won't make you popular with neighboring campers ?

Thank you for this info. I had no idea about the tax credit.
Lastly, in the US if you install a hard wired EV charger you should be able to recoup some of your costs through a federal tax credit.

There are a lot of good points here about wire sizing etc. The last point I'll make is about having the work permitted and inspected. It gets an extra set of eyes on it to make sure the electrician isn't cutting corners and that the install is safe. Part of that process is also to notify the utility as well for capacity planning purposes.

I have Tesla Wall Connector on a 60 amp circuit, #6 90C THHN in conduit. I have seen quite a few of these melted outlets over the years and I am very passionate about EV charging safety. Hardwired is the way to go especially with large battery like in the Rivian.

 

[Ngkgb]

An update on this: electrician came out and hardwired our new charger and said previous electrician had used #8 wires. Not sure if this contributed to the issue. I think #8 should be ok for a 30A charger but not for the 50A breaker. We updated the wire to a #6 and will
Be charging at 40A.

 

[Mathme]

I'm not an electrician, but my understanding is that you only set the truck/charger to charge at 80% of the rating of the lowest component in the line: breaker, wire, or outlet. What it looks like :

Item	Rating	Charge Setting
Breaker	50a	40a
10 Gauge Wire	30a	24a
8 Gauge wire	55-65a	40a
4 Gauge Wire	85a	48a
Outlet	30a	24a

From what we can see from this example is you have a 50a breaker, 10 gauge wire, and a 30a outlet, so charging should be set to 24a max of 24amps. For added safety, I'd set the limit at the charger so that the vehicles have to accept that rate. If you don't the truck may think you have a 240 outlet and try to draw upwards of 40amps.

I've also seen examples of where people are constantly plugging different car chargers into the same wall outlet and this can be hard on the outlet as they really aren't designed to be used like that.

At my place we charge a Tesla Roadster and the Rivian off the same 14-50 charger set to 40 amps. My electrician (who did the complete rewire during a remodel) said we could go with either a hard-wired or plug option for our charger. We decided to go the plug route as that gives us more flexibility to change the charger without involving the electrician again (we've had a bad one replaced under warranty). About 2-3x a year, the Wallbox manages to get itself all wound up and confuddled and needs a hard reset. In these instances I reset via the breaker rather than unplugging the outlet.

In your case, I'd get an electrician to check come out and look at the box and have them fix it. I'd also ask about the feasibility/cost of upgrading possible 10-gauge wire to 6 and if your house will handle the load. If you can upgrade the wiring, then go for the faster charge up to 40a however, if your house can't handle it, then 24amps it is.

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