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melted connector!

Tesla Model S plugged into standard 220v outlet, retrofitted with a 1450 connector. MELTED - thank God it happened and we caught it instead of going to bed. lots of rancid smoke.......scary

Scary! Can you define "retrofitted"

Uh... why is the connector upside down?

I thought the picture might be inverted, but the drips seem to say it is not.

That is a problem that should be corrected.

Wow, that is scary. Did you ever feel the charing cord to be warm long before this. Is this recent Model S cord or older 8 months old or so? The older cords likely have an issue and may have a build up of a rust like stains that deposit on the chrome pins that you can see when you separate the Nema 14-50 from the cord. From the looks of this you should have had a warm cord long before this. Also you may have issues with your breaker box, bad breaker or wrong wire to breaker match, have that check NOW.

Are you certain that you didn't spill peanut butter on it?

A few things seem odd about this picture. I'd like to see the OP post this as a private message, as well, to verify that he is a model S owner.

However, this is a known problem that Tesla released a software fix for, that limits the current (Amperage) charging from a 14-50 connector. In addition, Tesla has started shipping replacement 14-50 connectors that have temperature cutoffs. This is the subject of the controversy over whether to call it a "recall" or not.

I would like to see a few follow up pictures, like maybe scrape off the melted parts and show us what the connectors themselves look like. I question the simultaneous melting at the same rate on both the connector side and on the UMC side.

I agree that it's nonstandard that the wall plug is upside down. I wonder if the person did this retrofit himself, or if he had it done by a licensed electrician. Still, Tesla should assume that some people will do their own installations, and design the equipment to handle power surges. It is already designed to be nonfunctional when the pins are connected improperly.

Seems to be a real guy, not hiding:

My original 1450 outlet was also installed upside down like in that picture, by a professional electrician who is also a family friend. I didn't think it mattered, so plugged in the UMC adapter upside down for 10 months until replacing it with a HPWC. I can see how an electrician can easily put that particular outlet upside down given that it has four prongs.

This appears to be a resin that is used inside the Nema 14-50 and or the cord that has over heated, got soft and flowed though the opening created after the plastic melted. Again that breaker should have tripped before this he needs to get that checked. That is the same color of the stuff I thought was rust, it was not rust. If that resin builds up on the connectors inside where the two meet it gets warm then next the breaker starts to trip.

What did you mean by retrofit. Did you replace the original outlet with a 14-50? If so, what was the original outlet? You didn't replace the original breaker with a new 50A one did you?


Yeah, Allan has some interesting friends if you check out the images.

The issue with the connector upside down is that it potentially puts a lot of leverage on the connector which wouldn't be there if it was installed properly.

Is it a real problem... I can't confirm. But with multiple connections, it's one potential issue that could be eliminated. It also tends to put a sharper bend in the cable near the plug and, assuming the plug is a decent distance from the floor, the weight of the control box will sharpen the bend instead of pulling the cable straight. Sharp bends are potential problems.


Of course Tesla's instructions show that the ground pin should be up.

The problem is a resistive connection between the cable and the adapter. The 14/50 outlet, though upside down, looks fine. Everything looks straight in the photo, so I expect the weight of the cable is supported from above. If not, the upside-down cable exit could compromise the connection integrity. Note that a resistive connection will not trip a breaker because it is not an overcurrent condition. However, if a new adapter was being used, it should have tripped the thermal switch. Was it a new one or an old one?

That's the first time I have seen a 50 amp outlet wired into a single gang box. That had to be brutal to get four heavy 50 amp leads crammed into a single gang box. I have a hard time bending the leads and stuffing them into a standard double gang box.

@McClary, how can you tell it's a fake?


I would bet the outlet wiring is not the right size. The outlet likely is getting hot and melting the lowest temp capable materials. I would for sure check out the breaker, wire size and outlet wiring connections. You would have to be a magician to connect the proper size wires to a 50 amp outlet and stuff it all into a single gang box.

By the way there is no such thing as a "standard 220 volt outlet"

You really need to make sure you have number 6 or larger wire to run a 50 amp continuous load outlet. I still can't see how you can fit a NEMA 14-50 connected to 4 number six wires in a single gang box. Something is not right with that outlet.

Yeah, I think we have a space issue in that box. Not willing to pull out my code manual this late at night, but having done a few, I can't imagine mashing that much wire into that small a box.

You guys are right. It is a huge code violation for that receptical to be in a single box. It would not be possible to get 8ga much less 6ga installed correctly. 30amp circuit it max for single box.....

Connector contacts use the wires as their heat sink. Depending how the outlet was "retrofitted," the wires might be under-sized, allowing excess heat to build up.

Also interesting to note that the knee-jerk software "fix" that's driving some owners crazy failed to prevent this. But I'm not surprised: the EE in me says attempting to detect heat buildup using a voltage drop can only work some of the time, at best. Especially when it doesn't stop charging altogether (which would be more intolerable to drivers).

Additional thoughts:
1) Circuit breakers only prevent against excess CURRENT, not faulty wiring; the Tesla was only drawing its 40A (or whatever), the connector just had too much voltage drop. So it's not at all surprising the breaker didn't trip
2) Why is everyone so quick to think this is faked?

I would expect the light weight rubber charge cord and components would melt before the outlet components.

The outlet is made of a non flexible phenolic material and the contacts are metal terminals, the wires are rated for in wall operation and the box is also fire rated to contain or delay electrical fires.

So the outlet assembly is designed to hold up under high heat and loads to protect the structure. The cord is designed to be light, flexible and portable. The cord is not designed for in wall installation.

When the OP stated he used a standard 220 outlet red flags went off in my mind. When I looked at the picture and observed a 50 amp outlet in a single gang box more red flags went off. Not to mention the outlet is installed upside down.

I am concerned that the OP may have lucked out and had the cord melt down from heat transfer thru the plug prongs. Had the cord not melted down the failure could have been the in wall wires and outlet setting the house on fire.

The OP really really needs to have his entire 14-50 installation inspected by a qualified electrician before he potentially experiences a house fire.

No guys, the resistance in this is happening in the charge cable, thus that is where the heat is building up and melting the cable end. Yes he may have the wrong breaker to wire match, but it is not that too many wires are in a small box that is causing this or we would see damage there also.

Oh my goodness. I should not have left everyone hanging on all their inquiries. Love the "it's a fake" conspiracy theory people....

I am a real guy, live in Huntington Beach CA.
The 'retrofit' I discuss was putting the 1450 plug on an existing, 30 amp 220 wall connector. So it is a 1450, but with only 30 amps of service behind it- too lazy to replace the breaker and the 10 gauge wire would not be up to code for the 50 amp service.

I reduced the charge voltage to 25 amps in the car, charges overnight easily.

The plug is upside down as the cable travels up the wall, across the ceiling of the garage and drops down to where the car is parked.

Not only am I not a fake (in regard to owning a Tesla anyway), I actually own 2 model S....sorry to crush the conspiracy:

FYI, Tesla offered to bring me a replacement cable LAST NIGHT at 9:30pm. I am picking the replacement up from the Torrance service center today at 2:30pm, in case anyone wants to come and say hi!

going into a meeting but look forward to continuing the thread later this afternoon. let me know if anyone has more questions!

McClary speaks in non sequiturs. Who seriously thought this was fake?

25/30 is over the 80% threshold for sustained use. I am sorry to see the damage but would seriously recommend going to lower than 24 amps after you get everything repaired.

Get Tesla to check out the car.

I would also recommend ensuring wires to the plug (backside) are extremely tight and have a good connection. My box and adapter melted due to resistance inside the box. This in turn heated up the NEMA 6-50 adapter and caused damage to it. Thankfully the UMC and car were fine but I had them verified by Tesla just to be sure. Safety first!

Good luck and sorry again to see the damage.

I guess it's a good thing there wasn't a house fire. It is against code to install a 50 amp outlet on 30 amp wire (not relevant what the breaker is) Don't ask why just ask an electrical inspector.

I know it's just temporary but your home owners insurance would not have covered the fire if there was one. They would have wanted to see the permit and inspection of that installation.

This a perfect example as to why people should be calling electricians and having the job permitted and inspected.

Get a NEMA 10-30 and the right adapter for the UMC. If you are honestly charging at 25 amps like you claim why replace the outlet and not just get the correct adapter? That is the only thing I see as squirrely in about this post.

Why not use a NEMA 10-30 or a NEMA 14-30 and do it properly.

If you have a common and two hot leads use a 10-30. If you have a common, two hot and a ground use a 14-30.

Not worth burning your house down over a simple wrong sized outlet, wire and breaker. It will take a lot more heat to melt down the outlet than to melt down the adapter. Lucky for you the cord melted before the outlet melted down.

The connection terminals on a 14-50 are not designed to properly clamp onto 10 gauge wire. A poor wire connection will generate lots of heat under steady load conditions.

If the Tesla 14-FIFTY male pin adapter is snapped on, will the car not try to pull up to 40 amps, or whatever is manually set on screen ? The car doesn't know your house wires are hot, right ? Geez. If so, than that plug should NEVER be on a house line that is not tightly on at least 6ga and a 50amp breaker. This business of building extention cords and retro-electro if wide-spread is going to get people hurt. 110v buzz is nothing to a 240v hit, let alone fires. Please hire electricians.

I agree with most of the comments - it needs to be wired properly!

I'm 99% certain the NEMA code does not specify an orientation, and only in the last 5-10 years has it become a bit more common, but not regulated, to have the grounding pin up on any receptacle that has a ground. The idea is if the plug is only partly in place, the exposed grounding lug/pin is at the top, and should any tool hit it, it's better than hitting the live pins below it. Sort of a far-fetched case, but possible.

That said, I feel the orientation is more important to relate to the item being connected, and the cord that will be used such as the UMC. In this case, with the cord running upwards, the ground pin oriented down is likely to provide the least strain on the cord.

For all installations using the UMC I'd recommend a forked holder for the 'brick' portion of the UMC to further reduce any strain on the cord, no matter which orientation the NEMA connection is made. Here's one at Home Depot for less than $1:

Realizing there are several configurations of pins/plugs for various 30amp outlets. Perhaps TMC might consider a coupon for one additonal adapter of your choice, to thwart 50's plugged into 30's etc ... Folks burning down houses with no insurance coverage hire lawyers, etc, etc ...

@slipdrive - I'm not sure you're aware, but you can't plug a higher amperage connector into a lower amperage receptacle. They are all uniquely keyed with different arrangement of blades.

In the OP's case, they improperly replaced a 30 amp receptacle with a 50 amp one, a major no-no, since the wiring and breakers were left at 30 amps, and the box is not rated for 50 amp service (it requires a dual-size box or larger).

Lots of good information, appreciated.

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