melted connector!

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

PBEndo | 3 februari 2014

Scary! Can you define "retrofitted" | 3 februari 2014

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.

wbrown01 | 3 februari 2014

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.

Thomas N. | 3 februari 2014

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

TFMethane | 3 februari 2014

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.

Pungoteague_Dave | 3 februari 2014

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.

wbrown01 | 3 februari 2014

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.

David70 | 3 februari 2014

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? | 3 februari 2014


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.

David70 | 3 februari 2014


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

Out4aDuck | 3 februari 2014

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?

Roamer@AZ USA | 3 februari 2014

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.

DTsea | 3 februari 2014

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


Roamer@AZ USA | 3 februari 2014

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.

Roamer@AZ USA | 3 februari 2014

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.

jbunn | 3 februari 2014

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.

Webcrawler | 4 februari 2014

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.....

theapple | 4 februari 2014

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?

Roamer@AZ USA | 4 februari 2014

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.

wbrown01 | 4 februari 2014

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.

alan | 4 februari 2014

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!

Bighorn | 4 februari 2014

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

Joshua Burstyn | 4 februari 2014

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.

Sudre_ | 4 februari 2014

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.

Roamer@AZ USA | 4 februari 2014

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.

slipdrive | 4 februari 2014

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. | 4 februari 2014

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:

slipdrive | 4 februari 2014

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 ... | 4 februari 2014

@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).

alan | 4 februari 2014

Lots of good information, appreciated.

Pungoteague_Dave | 4 februari 2014

@sudre - "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."

Sudre - Homeowners insurance does insure for mistakes and owner stupidity too (that's why we have insurance). I am NOT saying this owner was stupid - I also used an upside down 1430 for months, although without incident, until installing a HPWC in its place). Amateur electrical and plumbing work, improperly amp outlet/breaker size, improper extension cord usage, silly storage decisions start fires every day. Policies pay off for non-code electrical fires every day, even though some technically have the ability to deny the claim for gross owner negligence. Many fires result from owner or professional builder/installer mistakes of one kind or another - that's why we have insurance. Technically, many policies have requirements that work be done to code, and they could possibly use the clause to deny a claim, but in practice, that is very unlikely.

Put another way - almost every house has some sort of out-of-code situation, and insurance companies do not reject claims on that basis. However, some insurance companies will provide a discount or subsidy to bring a house up to current code, such as upgrading an old fuse box to breakers, replacing knob-and-tube wiring. From a post about this issue over on TMC:

"I actually called my home owners insurance company, USAA, and posed this specific scenario. I was assured that my company would pay the claim provided there wasn't intentional malice (intentionally trying to burn the house down). Just having a 26 foot cord or a 126 foot cord where a 25 foot one is specified by NEC was not a factor for them. Again, they made it clear that an electric vehicle charge cord longer than 25 feet would not be a factor, even if it was the cause of the fire and in "violation" of NEC, and any other industry standard. They did mention that following industry standards for wiring was encouraged, but something that didn't meet those standards wasn't the "smoking gun" to prevent them from paying the claim... again, without malice.

They did mention that if an older house had "knob and tube" wiring, an inspection would be required of the house, and the homeowner would be given time to repair anything UNSAFE, but they would still be fully covered the entire time the policy was in force. You might want to check your ACTUAL insurance company if you consider this an issue, rather than be swayed by unqualified internet blather.

Thirdly, it's a big world out there, and rules, regulations, insurance, etc, are different everywhere. Obviously, it's wise to understand the potential implications that are specific to your situation in your political jurisdiction.

If you have an insurance company that would use such an issue as a reason to disqualify your claim, my company suggested that "you get what you pay for", and I couldn't agree more."

slipdrive | 4 februari 2014

Yes, thanks. By "50's into 30's" I meant unknowingly rig it to do that. I was just pondering what might keep people from avoiding doing it correctly. In OP's, maybe they didn't realize there were 30 amp heads.(?) I am curious, though, does the car detect the adapter, and adjust the charge limit just based on that ? Presuming that is the case, then the ability of people to make up extension cords is pretty concerning.... That 14-50 adapter head becomes enabling route to accidents, if ever rigged to get into smaller house outelts and associated wires. Bottom line of course, know what you are doing.

Pungoteague_Dave | 4 februari 2014

Put another way - almost everyone who has mounted their flat screen TV on the wall has committed a specific electrical code violation by cutting a hole and running the TV's power cord inside the wall. Your insurance company isn't going to deny a claim because you violated this code:

NEC ARTICLE 400 Flexible Cords and Cables General 400.1 Scope.
This article covers general requirements, applications, and construction specifications for flexible cords and flexible cables.
400.8 Uses Not Permitted.
Flexible cords and cables shall not be used for the following:
(1) As a substitute for the fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors.

In other words, running power cords through the walls is not a substitute for permanent wiring. You are supposed to install a new electric socket installed directly behind the TV, and plug in the power cord and coil up the slack. If you drilled a holes and ran cable yourself in and back out to a power socket, you are in violation of the code.

Insurance company denials of such claims are an urban myth. You have to actually intend to burn down your house to be denied a fire claim.

JenAlJill13 | 4 februari 2014

I'm an EE, and based on my own experience, I'm with the few people that feel the cable orientation is an important factor in addition to the non code work. My cable is connected properly, with the proper #6 wiring, installed by a licensed electrician, and the cable pointing down off the plug. That orientation minimizes the pull on the plug tending to slowly pull the plug or the 14-50 adapter off the wall receptacle. Unless I'm traveling, I never remove the UMC from the wall, but I have noticed that with time and the movement of the cable during charging sessions, the 14-50 adapter slowly pulls off the wall plug and starts to heat up because there is more resistance on the pins that are not making full contact. Based on my personal observation of a heated connector at least twice that correlated with the connector not being fully engaged, I am now charging at 30 amps and checking the wall connection every time I charge the car. So far, no additional problems. My advice is to start fresh and do it right.

RFD | 4 februari 2014

I agree that installing a 14-50 receptacle on a 30-amp circuit was not a wise move. However, based on what Alan said he did, the meltdown should not have happened. Somewhere in the vicinity of the outlet was a high resistance connection. It could have been between the charging cord and the 14-50 adapter, between the adapter and the receptacle, or between the receptacle and the incoming wires. The wire clamps on the receptacle have a minimum and a maximum wire size they are designed to accommodate. Too large a size and the wire won't fit. Too small and the clamp will not tighten enough to provide a secure connection. I am suspicious this may have been the problem.

If if the original receptacle was a 10-30 or a 14-30, a better solution would have been to spend $45 on the appropriate adapter from Tesla. You could still install, or re-install, a 30-amp receptacle and use the correct adapter.

Roamer@AZ USA | 4 februari 2014

If the proper 10-30 or 14-30 outlet was used with the proper UMC adapter the car would automatically draw a steady state load of 24 amps. The car reduces the breaker/outlet rating by 20% to account for the continuous load created by this application.

Thanks for posting this failure so we can all learn and be aware. This story caused me to wonder if my wife would know what to do if I was not home and the charge cord started overheating. In a panic she would likely attempt to pull the plug.

So my corrective action was to show her which breakers ( we also have two cars ) to flip in the garage sub panel. I also labeled them so she wouldn't have to spend time looking for the right breakers in a panic situation. I have not experienced even the slightest of overheating but it never hurts to learn from others and anticipate problems so corrective actions can be implemented.

Here is a picture of my emergency shutdown system made easy for my wife.

alan | 5 februari 2014

Again, many thanks for everyone's contribution here!

In regard to the 1450 plug, it is connected to existing home wiring on a 30A breaker, 10AWG wire. It was originally installed by licensed electricians, and since this issue has come up, Tesla is sending their electrician, the electrician that did the installation at all Southern California tesla service facilities, to my home tomorrow. I told him how the wiring was configured and he had no issue with it whatsoever, provided the pins were properly connected (which I am confident they are). I will report back after he visits my home tomorrow.

I fully understand the upside down connector concern, however Any weight/stress on the connector had been removed by supporting & securing the cable to the wall.

Roamer - Thank you for your input and the idea about labeling the breakers, this is a great idea that I will do today.

Peter7 | 5 februari 2014


There is one other issue that seems to have been introduced by Tesla's latest version of software. It would be worthwhile (to Tesla even more than you) to have them pull the cars charging logs and see if this scenario occurred.

If charging with a 14-50, at a reduced current, say 20 Amps, and the car sees a power issue it then reduces the current to 25% below MAX, in your case, that would be 30 Amps. In your case this would RAISE your current from 20A to 30A when a fault is detected. Because of your particular setup, this would now exceed the rating for everything on the house side (except the 14-50 outlet itself). This would then exacerbate the issue.

The very latest software version 5.8.7 (which seems to only be installed at service centers so far) MAY correct this software issue. You may want to make sure you have that installed also.

In any case, good luck and please keep up informed!


Peter7 | 5 februari 2014

*up = us

TheRaven | 5 februari 2014

Question. Have had S85 since June. Solar City installed 14-50 outlet in garage with #6 cable to breaker box. All seems good, but the UMC cable does get warm when charging at 40 amps. Is this normal?

jajabor | 5 februari 2014

Somehow the photo does not convince me as real!

Joshua Burstyn | 5 februari 2014


Warm is OK although we could try and find out what the cable is rated for in terms of temps. :-)

Bighorn | 5 februari 2014

I've seen something similar with my homemade 6-20 adapter. I have it manually set to 16A and a couple times there's been a power surge that has caused an intervention by the new program. It set's my amperage to 30A and then I think it totally shuts it down. All was well before the new 25% safety reduction software.

Galve2000 | 5 februari 2014

I've done a number of gut renovations to homes and apartments and every single electrician or contractor I have used flat out refused to pull the power cord of the TV through the wall.

It gives me piece of mind to know that these professionals are not being careless with my "investment."

Really, installing a new (recessed) outlet behind your plasma/LCD screen is not that big a deal.

alcassfast | 6 februari 2014

GM executive?

KWTESLA | 6 februari 2014

Re-do the whole thing to be sure. New breaker ,box ,6/3WG wire best quality Nema 14/50 look for a nylon receptacle. Or better still order and install HPWC. Do it right or you might burn your house down!

I have said this before in the forums wall receptacles are not made to be plugged in & out repeatedly as in daily . In installations of high use you buy the best. Most 50 amp receptacles get used once until the range is replaced.
The contact clamping devices inside the wall receptacle get loose with frequent use and things get hot with loose connections. Some of you may have sloppy 120 receptacles you plug you hair dryer into every day . Do you have to wiggle it to make it work ? That is also a potential fire hazard.

Alan get new parts! Think HPWC . Be safe !

JPPTM | 7 februari 2014

KWTESLA--since I have heard the same issue with the NEMA 14-50 and repeated insertion/removal issues, I own 2 NEMA 14-50 adapters for my UMC. 1 always stays plugged into the wall, and 1 in my black mesh UMC bag for travel. Figure it is cheaper/easier to replace the adapter than call out the electrician to replace the receptacle.

alan | 9 februari 2014

Thanks again for everyones input and contribution. FYI, the charge cable was always plugged in - I haven't had any need to remove it, ever. It is secured to the wall to keep the weight from pulling on the connection.
Tesla was very helpful and replaced both charge cables [we have two Model S], sent their electrician - at their expense - out to my home to evaluate both connections. Electrician found nothing wrong with the electrical configuration or installation (30A > 10AWG > 1450). They determined that the cable was at fault. I am a little concerned that I had heard of the cable "recall" via a press release, but not a dedicated email offering to swap it. I assumed without a direct correspondence from them, that the cable issue didnt involve me (based on VIN) Anyone else?

Brian H | 10 februari 2014

It was a converter recall, not a cable recall.

jon | 22 september 2014

I just had the mobile connector and the nema 14/50 adapter melt. One of the pins (and only one of the pins) got very hot and burned/melted the male & female parts. I was using the new nema 14/50 adapter (the grey one). Tesla just replaced both the cable and the adapter but I'm wondering how widespread this issue is. My car was having trouble charging and that's why I noticed the issue. I've dropped my charge current down to 20A to ensure I don't have future issues.