Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Melted adapter and outlet

besnova

Member
Nov 10, 2017
110
42
New York
I feel like I have been in this forum so much more lately, it is like problems are just happening back to back! My car alerted me that charging was interrupted and that the charge port was open... strange, so I went to take a look. The charger was still connected and I was able to remove the charger without waiting for the light to turn white. I smelt burning and immediately checked the outlet. It melted through. I then turned off the circuit breaker and now I am without an outlet or adapter. I read some posts but all I could find is that it could have been a loose connection. I emailed Tesla as well. Any thoughts and recommendations on this? I feel like now I want to install a lower outlet even though my circuit breaker is 50A and wiring is 6-gauge over about 75-ft and pulling 40A with no issues. I have had no problems since having my car for years with no charging problems at all. It is a 2014 Model S P85 with 110K miles.

The charger itself on both ends except for the adapter look completely fine and not hot to the touch. The adapter was very hot though.

The only thing I think I could do is see what Tesla says and buy a brand new NEMA 14-50 adapter and new receptacle and just make sure it is wired securely before closing.

IMG_1415.jpg
IMG_1416.jpeg
IMG_1417.jpg
IMG_1419.jpg
62450482936__73B62F35-FE6A-475F-BF21-29F761A1671F.jpg
IMG_1420.jpg
IMG_1421.jpg
 

animorph

Active Member
Apr 1, 2016
2,133
1,529
Scottsdale, AZ
I agree with your search results. Probably a loose wire connection to the outlet. That one side of the outlet had the majority of the damage and looks like the heat source to me. A new outlet and most likely a new adapter plug should fix the problem. The wire to the outlet may not have been torqued enough during installation and loosened more as it heat cycled.
 

jmaddr

Member
Mar 29, 2019
891
894
Florida
What outlet did you use and how often do you connect/disconnect the mobile charger? At one time, Tesla use to list specific outlets designed for RV use (Cooper maybe) which could be constantly connected and disconnected but they were like 60 to 90 bucks vs the 10 Leviton ones you can get at Home Depot.
Maybe the constant plugging and unplugging of a 10 dollar outlet finally caused a loose connection?
 

besnova

Member
Nov 10, 2017
110
42
New York
What outlet did you use and how often do you connect/disconnect the mobile charger? At one time, Tesla use to list specific outlets designed for RV use (Cooper maybe) which could be constantly connected and disconnected but they were like 60 to 90 bucks vs the 10 Leviton ones you can get at Home Depot.
Maybe the constant plugging and unplugging of a 10 dollar outlet finally caused a loose connection?
I charged anytime I got home, so sometimes it could be for 1 hour or 8 hours straight charging to 90%. I haven't heard of outlets designed for RV/EV but I will look into those. This outlet was fine all these years up until recently, so I am suspect of the heat resistance behind one of the pins/contactors. It just sucks because you never really know when they need to be tightened again.
 

besnova

Member
Nov 10, 2017
110
42
New York
I was able to find again what I referenced above. Please see:
https://www.tesla.com/sites/default/files/downloads/universalmobileconnector_nema_14-50.pdf
Specifically it mentions:
View attachment 599170
The Cooper is like $60 and the Hubbell is around $100. The Leviton at Home Depot is $8.89 which is why most just go with that.
Thanks so much. I was following that guide a long time ago but I can't believe I missed those recommended outlets. I ordered the Hubbell from Amazon for $90.03 and ordered a new Gen 1 NEMA 14-50 adapter from Tesla for $48.99, totaling $139.02 for the replacements. I appreciate the help. There was a cheaper Hubbell in other sites but shipping speed added it to the same price as Amazon's Prime.
 

SlyWombat

Member
May 15, 2014
275
104
Mississauga, ON, CA
The key reason is if you plug/unplug the mobile adapter that puts the wear and tear on the plug. My mobile was plugged in almost all the time except the the RV was in the driveway, but I had the switch (code here) that is above the outlet melt and fuse together. Forgot to take a picture of the fused part, but you are supposed to be able to pull that handle to disconnect the circuit, but it was melted in there and could not remove it. Could not tell from outside that it was a mess in there. Still all worked, I was upgrading to add an dedicated RV outlet, so it was replaced with a subpanel instead.PXL_20201001_183403553.jpg
 

ucmndd

Well-Known Member
Mar 10, 2016
6,413
11,965
California
The state of the wire and insulation on the other side of the receptacle may necessitate the running of new conductors - be prepared for that.

get into the habit of thoroughly inspecting the circuit and the torque on the connections once or twice a year.

Consider charging at 32 amps instead of 40. That’s more than fast enough for nearly all situations and greatly reduces the potential for these sorts of issues.
 

mspohr

Well-Known Member
Jul 27, 2014
9,255
10,783
California
The state of the wire and insulation on the other side of the receptacle may necessitate the running of new conductors - be prepared for that.

get into the habit of thoroughly inspecting the circuit and the torque on the connections once or twice a year.

Consider charging at 32 amps instead of 40. That’s more than fast enough for nearly all situations and greatly reduces the potential for these sorts of issues.
I charge at 32 amps at home. I have a HPWC hard wired. Never a problem getting full charge by morning. Much less stress on the system.
As an electrical engineer, I always err on the conservative side. Just because something is rated maximum 40 amps doesn't mean it's a good idea to run it at that all the time.
 

besnova

Member
Nov 10, 2017
110
42
New York
Dropping from 40a to 32a drops the heat by about 36%.
That is substantial especially that I can even go on with 20A charging overnight. 40A se
I charge at 32 amps at home. I have a HPWC hard wired. Never a problem getting full charge by morning. Much less stress on the system.
As an electrical engineer, I always err on the conservative side. Just because something is rated maximum 40 amps doesn't mean it's a good idea to run it at that all the time.
That is a good idea. I rarely come home with under 10% battery, usually over 60% so 32A or even lower will be good enough for me. When I do get really low, charging to 90% is about 200 miles of range for my P85 and if I plug in at midnight and unplug at 8AM, 8 hours of charging at 40A (25 mi/hr for me) is perfect. But that is probably the tightest scenario as I usually plug in early evening AND come home with over 50% SoC.

When I get this all setup again I will start low maybe 20A to find a good sweet spot. From my personal experience and needs 40A is more than enough, but I set it up this way originally so that I have the freedom to choose if I did need it. Thank you all for your inputs.
 
  • Like
Reactions: ucmndd

mspohr

Well-Known Member
Jul 27, 2014
9,255
10,783
California
That is substantial especially that I can even go on with 20A charging overnight. 40A se

That is a good idea. I rarely come home with under 10% battery, usually over 60% so 32A or even lower will be good enough for me. When I do get really low, charging to 90% is about 200 miles of range for my P85 and if I plug in at midnight and unplug at 8AM, 8 hours of charging at 40A (25 mi/hr for me) is perfect. But that is probably the tightest scenario as I usually plug in early evening AND come home with over 50% SoC.

When I get this all setup again I will start low maybe 20A to find a good sweet spot. From my personal experience and needs 40A is more than enough, but I set it up this way originally so that I have the freedom to choose if I did need it. Thank you all for your inputs.
A while back, someone on this forum calculated charging efficiency at different charge rates (sorry, don't have the link now). Factors included resistance losses in the wire, charger efficiency in the car and battery cooling system. if I remember correctly, maximum efficiency was about 30-35 amps. (This was for Model S... YMMV)
 
  • Like
Reactions: besnova

beatle

Active Member
Aug 31, 2019
1,044
510
Springfield, VA
That's been my experience with charging amperage as well. 32A is more efficient by a few percentage points than 40A - this is on the same gen 1 UMC.

It is a shame that Tesla doesn't allow the amperage to be changed remotely. Most of the time, charging at 32A is preferable unless getting ready for a trip, and then I want full juice.
 
  • Like
  • Informative
Reactions: nwdiver and besnova

besnova

Member
Nov 10, 2017
110
42
New York
That's been my experience with charging amperage as well. 32A is more efficient by a few percentage points than 40A - this is on the same gen 1 UMC.

It is a shame that Tesla doesn't allow the amperage to be changed remotely. Most of the time, charging at 32A is preferable unless getting ready for a trip, and then I want full juice.
Yeah I was gonna say the same, remote change would be useful. Although it is not changed often, it’s good to make the change in the fly when needed.
 

besnova

Member
Nov 10, 2017
110
42
New York
I got the Hubbell but I am just learning that it is actually wider in diameter than a standard NEMA 14-50R outlet. Standard is about 2.15in in diameter and Hubbell (and other industrial grade brands) are about 2.45in in diameter. So I can't use my original outdoor enclosure, but I ordered this outdoor rainproof 3R enclosure, which is rated and made for RVs, only to find out that the hole diameter is the same. I have been searching around but can't find a rainproof 3R enclosure that has a 2.45in hole diameter for this Hubbell outlet. This is a pain in the ass.

I found some wall plates and etc, but they are made for indoor installs. Any ideas?

Also, the enclosure I bought already has a NEMA 14-50R outlet installed in it and it says it is made for RV only. I'm not sure if this would be okay for EV though. However, just looking at the diameter of both outlets it looks like the standard sized one and not an industrial outlet.
 

Electric700

Active Member
May 21, 2013
1,698
361
Florida, United States
Why not just replace the whole enclosure, including the outlet? I saw the one you ordered but haven't heard of that brand. See:

Midwest Electric Products 50 Amp Temporary RV Power Outlet-U054P - The Home Depot

Also:
Outdoor NEMA 14-50 outlet - Google Shopping

You can order a new Tesla Gen 1 MC 14-50 plug here:
Gen 1 NEMA Adapters

While you're at it, I think it's a good idea to install one of these whole house surge protectors if you don't already have one (or similar):

GE Whole Home Surge Protection Unit-Panel Mount-THQLSURGE - The Home Depot

I got the Hubbell but I am just learning that it is actually wider in diameter than a standard NEMA 14-50R outlet. Standard is about 2.15in in diameter and Hubbell (and other industrial grade brands) are about 2.45in in diameter. So I can't use my original outdoor enclosure, but I ordered this outdoor rainproof 3R enclosure, which is rated and made for RVs, only to find out that the hole diameter is the same. I have been searching around but can't find a rainproof 3R enclosure that has a 2.45in hole diameter for this Hubbell outlet. This is a pain in the ass.

I found some wall plates and etc, but they are made for indoor installs. Any ideas?

Also, the enclosure I bought already has a NEMA 14-50R outlet installed in it and it says it is made for RV only. I'm not sure if this would be okay for EV though. However, just looking at the diameter of both outlets it looks like the standard sized one and not an industrial outlet.
 
Last edited:
  • Like
Reactions: besnova

nwdiver

Well-Known Member
Feb 17, 2013
7,781
10,019
United States
I charge at 32 amps at home. I have a HPWC hard wired. Never a problem getting full charge by morning. Much less stress on the system.
As an electrical engineer, I always err on the conservative side. Just because something is rated maximum 40 amps doesn't mean it's a good idea to run it at that all the time.

Yep. I rarely charge >20A on my HPWC that can provide up to 80A. Heat generated by current increases exponentially. I^2 R.

I wish that Tesla would encourage this. Adding the ability to the app to change the charge rate would help. I think some people don't lower it because sometimes they need the faster rate and it's inconvenient to go into the car to change it.
 

besnova

Member
Nov 10, 2017
110
42
New York
Why not just replace the whole enclosure, including the outlet? See:

https://www.lowes.com/pd/Eaton-50-Amp-GFCI-Receptacles-Overhead-Temporary-Power-Panel/3027570

Also:
Outdoor NEMA 14-50 outlet - Google Shopping

You can order a new Gen 1 MC 14-50 plug here:
Gen 1 NEMA Adapters

That is the plan but the issue that came up is that all these enclosures are made to fit the standard sized NEMA 14-50R outlets which is about 2.15in in diameter. The Hubbell NEMA 14-50R outlet is actually wider in diameter at about 2.45in. So most, if not all, of these enclosures that I am finding are not made to fit this Hubbell outlet. I will continue my search in Google as I've been looking on eBay, Amazon, Home Depot, and Lowe's. Also, I ordered the Gen 1 NEMA 14-50 Adapter from Tesla already.

If I can't find any other enclosures, I'm going to just manually widen the hole in the enclosure to fit the Hubbell, I don't have a choice. They sell faceplates for the Hubbell outlet but that is only for indoor use. My charging setup is outdoors, about 75-ft away from home. I live in an apartment building, so indoor charging is not an option.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top