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Schmelted UMC/NEMA 14-50

yobigd20

Well-Known Member
Oct 28, 2012
5,926
528
Skaneateles, NY
Just had my UMC + NEMA 14-50 replaced today. Schmelted the old one. It still worked, but clearly faulty.

schmelted_umc.JPG
 

yobigd20

Well-Known Member
Oct 28, 2012
5,926
528
Skaneateles, NY
Not really sure - I have the newer style adapter and this should not happen with it. Only reason I discovered it was during a conversion with a Tesla rep that they were replacing all the original adapters with newer ones. We inspected my NEMA 14-50 and I had the newer version already (the old version were earlier than my vin, so most people have the new ones already, must be earlier than 5k vins)).

Anywho, upon looking inside it we found it melted both the adapter and UMC. He was very surprised to see that I had the new one and yet this still melted. He did mention something like when you click the adapter onto the UMC that it needs to be fully clicked in - no gaps. He mentioned something like the metal clip in the original was flimsy and sometimes this wouldn't snap on fully and if that happens and there is a gap between the adapter and UMC it causes it to melt like that. This should be fixed with the new adapters but clearly not as mine was already melted and he's definitely never seen it happen with the new ones until mine...
 

brianman

Burrito Founder
Nov 10, 2011
17,519
2,981
Just had my UMC + NEMA 14-50 replaced today. Schmelted the old one. It still worked, but clearly faulty.
When I went to get my tires rotated, I got replacement adapters for 14-50 and J1772.

My understanding/recollection is that the 14-50 replacement was to deal with the melting issue while the J1772 was just that some cars and/or stations had fitting issues.
 

brianman

Burrito Founder
Nov 10, 2011
17,519
2,981
The J1772 versions have different TPNs (part numbers).
Left is my original (U.S.) Signature vehicle J1772 Adapter.

TSL02 to J1772 ADPTR
P/N: 1005617-00-A
S/N: T1200000446

DO NOT USE IF DAMAGED
ENCLOSURE: TYPE 4
CAUTION - NOT FOR CURRENT INTERRUPTING
TEMPERATURE RATING: -22F(-30C)~122F(50C)
INPUT & OUTPUT: 240VAC, 50~60Hz, 80A MAX
READ OWNERS MANUAL BEFORE OPERATING
TESLA MOTORS, INC. PALO ALTO, CA 94304

TSL02 to J1772 ADPTR
P/N: 1005617-00-B
S/N: T1300023806

DO NOT USE IF DAMAGED
ENCLOSURE: TYPE 4
CAUTION - NOT FOR CURRENT INTERRUPTING
TEMPERATURE RATING: -22F(-30C)~122F(50C)
INPUT & OUTPUT: 240VAC, 50~60Hz, 80A MAX
READ OWNERS MANUAL BEFORE OPERATING
TESLA MOTORS, INC. PALO ALTO, CA 94304


Functional differences reported by Tesla:
  1. Better fit for the broad array of J1772 EVSEs in the marketplace.

Observed differences:
  1. P/N change from 1005617-00-A to 1005617-00-B.
  2. Newer one is shinier.
  3. Color change from gray to bluish gray.
  4. Triangle-with-exclamation icon next to the "CE" logic changed from yellow to white, and no longer has an inset black triangle.

As for the 14-50, my new one has...
1014324-00-B
... on it. I presume the original ends with "A". But that's just a guess as I don't have my original one.
 
Last edited:

FlasherZ

Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
7,024
1,013
I had one of the newer 14-50 adapters too when mine was replaced. It just appears that over time, some UMC's are not making full contact and it's generating heat.
 

Alpha

Member
Dec 4, 2012
406
0
Earth
I was just pondering today- the UMC and cable sure does get hot - couldn't they make a bigger, thicker version that would stay cool?
Sure it would be more bulky, but I wouldn't mind that since it stays fixed in my garage 99% of the time (and I could still keep the current, more portable version for road trips...)
I would think the cost savings over time (in less wasted electricity) would add up! So surely that's worth something...
Correct me if I'm way off...
 

montgom626

Active Member
Dec 15, 2012
1,328
0
USA
I was just pondering today- the UMC and cable sure does get hot - couldn't they make a bigger, thicker version that would stay cool?
Sure it would be more bulky, but I wouldn't mind that since it stays fixed in my garage 99% of the time (and I could still keep the current, more portable version for road trips...)
I would think the cost savings over time (in less wasted electricity) would add up! So surely that's worth something...
Correct me if I'm way off...


I lose 3 kW per day from vampire loads. UMC is irrelevant when it comes to kW lost.
 

qwk

P130DL
Dec 19, 2008
3,024
766
^^^That might solve the melting problem, but not the UMC malfunction problem.

BTW, the old 14-50 adapter does have a part number that ends in A. The new ones have a B.
 

Alpha

Member
Dec 4, 2012
406
0
Earth
I lose 3 kW per day from vampire loads. UMC is irrelevant when it comes to kW lost.

Charger has been measured to be only 86% efficient, thats way more than 3kW per day of loss! Some of that is probably from the rectifiers in the car not being 100% efficient, but some is also probably from the heat loss.

And besides, vampire load will be fixed by end of year (or so I've heard.)
 

brianman

Burrito Founder
Nov 10, 2011
17,519
2,981
^^^That might solve the melting problem, but not the UMC malfunction problem.
BTW, the old 14-50 adapter does have a part number that ends in A. The new ones have a B.
Thanks for the confirmation, qwk!
 

FlasherZ

Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
7,024
1,013
May be the best way is to forget about using UMC charging at 120V. Cut the end of the AC plug and wire to a Home Depot 14-50 plug.

The adapters contain components (mostly resistors) that tell the UMC what type of a plug is connected. You'd have to duplicate those too, if you wanted to hardwire a specific plug onto it.

- - - Updated - - -

^^^That might solve the melting problem, but not the UMC malfunction problem.

BTW, the old 14-50 adapter does have a part number that ends in A. The new ones have a B.

Correct, although my rev B adapter is what melted. I've since gone to the HPWC, so I don't use my UMC anymore except on the road to tell you my experiences.
 

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