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Bad electrician ran 6/2 to my NEMA 14-50, what to do?

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EarlyAdopter

EarlyAdopter

Active Member
Jun 24, 2012
2,841
2,099
Redmond, WA
#1
I finally decided to get a 240V 50A line run out for my Model S. I've been doing fine on 120V 12A, so this wasn't urgent, but with a Model X on the way for my wife it seemed like a good time to do it.

I got a bid from the EV branch of a local solar company that I _thought_ was reputable, but ended up with an absolute mess of a hacked, incomplete install. Absolutely terribly incompetent. I've fired them and don't ever want them near my electrical (or anyone else's for that matter) again. I shudder to think what shoddy work they've done elsewhere.

Here's what they did:

  • Tried to put a slim THQP breaker in the top slot in my GE panel, which doesn't accept them in the top slots. They then tried to physically modify the breaker and the breaker slot in the panel to make it fit. I rose a living fit when I discovered this and had them put everything back and told them to never call back.
  • Ran 6/2 NM-B cable above the drywall in the garage ceiling to a NEMA 14-50 outlet. No neutral wire. Fine for a UMC, but clearly not to code.
  • Nicked the living hell out of the conductors when stripping the ends of the cable.

I moved a couple of other breakers to THQP's further down and put a full sized 50A breaker in the top slot, cut the nicked ends off and restripped the wire, and torqued it all down properly, so I have a functional install. But I'm left with a 6/2 run to a NEMA 14-50 and need to get this inspected. What should I do?

Options:
  1. Run a new, proper 6/3 cable to the outlet. This will be a major pain and expense to re-run a new cable.
  2. Run a single 6/1 strand to wire up the neutral. Would this be to code?
  3. Swap the NEMA 14-50 outlet for a NEMA 6-50. I have a 6-50 adapter for my UMC sitting in the closet, so this would be pretty easy and do the trick. My only concern is it's the older style UMC adapter and not the redesigned, gray plastic center adapter like the new NEMA 14-50 recall replacement adapters.

What do people here think?
 
#3
miimura said:
I would change the outlet to 6-50.
Click to expand...

+1

I would take advantage that you are fortunate enough to own a UMC 6-50 adapter. There is nothing wrong with a UMC 6-50. Always check to insure an acceptable operating temperature of your equipment/UMC adapters including your 6-50 while charging. I wouldn't waste my time, money or copper installing an extraneous neutral conductor (needed for 120v camping) that the UMC doesn't electrically connect to (the neutral prong on a UMC 14-30 and 14-50 are dummy prongs with no connectivity). I would submit that most owners don't even need to charge at 40A for their average daily commute (you may consider a rate of 25-30A). I have been charging at 24A with a 160-mile commute for 38,000 miles.

Good-Luck!


btw, i would try to procure a back-up (as I did) UMC 6-50 adapter since it appears that Tesla has permanently discontinued this great UMC adapter
 
Last edited:
#4
Yes, switch to a 6-50 receptacle. The old 6-50 adapter will work fine. It may work forever, or you may have gotten a bad one, and it will degrade in a few years. The problem is that Tesla isn't making 6-50 adapters anymore.

So, here are some recommendations.

1 - since you've been living with 120v, just dial down your regular charging to 30A from 40A. This will reduce potential heat resistance by half. This should allow your 6-50 adapter to live forever even if you got a bad one. You can still charge occasionally at 40A if you need a quicker daytime charge...

2 - if you eventually do run into problems with your 6-50 adapter, you can always make your own 6-50 to 14-50 adapter and then use Tesla's latest 14-50 adapter.

3 - you can buy a Tesla HPWC (they recently lowered the price to $850 or something) and use that. You can set its dip switches to max out at 40A. This way, you get to keep your UMC in the car at all times.
 
#5
Buy one of the $500, eBay, Canadian HPWC's and install that. With the #6 wire, I think you can set the HPWC to a 60A Breaker, 48A charging. You will need to buy a new breaker, or set the HPWC to a 50A breaker/40A charging if you keep your current 50A breaker.

An HPWC will be good for any Tesla MS or MX, has a longer cable with cable storage, and will be more robust for long term use with heavier wires that won't get warm with 40 or 48 Amp charging. You and your wife can leave the UMC's in the trunks.

Sorry about your bad experiences, but at least you caught it.

Good Luck!
 
#9
Can you describe more fully why it would be so difficult to run 6/3 in place of the 6/2? Might it, for example, be possible to use the extant 6/2 to fish through the 6/3????
 
#10
If it's been installed correctly, it will be stapled somewhere close to the outlet box, and at the panel end as well, so you'll have to open the drywall at those two points (Even if it's not stapled, you have to open the drywall so you can properly staple the NEW cable. If you do that, then you might be able to use the old cable to fish the new cable through, so long as it's not too long. If it's long or bending around corners or through floors or ceilings, it would probably be pulled too tight in places. I'd go with the 6-50 or install a HPWC as others have suggested.
 
#13
Thanks for the responses everyone!

I had originally planned on using an HPWC, bought one, but sent it back for 2 reasons:
  1. It's big. Really big. At least 4x, maybe 6x, the size of the UMC. Just looked huge holding it up on the wall.
  2. The cord is twice as thick and not as flexible as the UMC cord. It sticks out from the car farther before draping down. I have a tight garage and regularly walk past the car and out the garage door on that side, so it makes a difference.
I don't need >40A charging. I only have a single charger on my current car and the same will be true for future cars, so it would only have been for aesthetics, but after seeing it in person that was out, and for over-engineered margin of safety. On the downside, if the HPWC ever died replacing it will be a pain. With the UMC, if it dies I just unplug it and plug in the UMC from the other car.

As for running a new 6/3 line, it's just going to be a pain. It's fished up inside the wall up and over the ceiling, down the opposite wall, with two 90 degree bends through holes in studs. Perhaps the only thing the electrician did well (heh, well, we'll see on inspection). $100 for new cable plus an hour or two of my time to fish a new cable just to wire up a neutral I'll never need just doesn't compute.

Sounds like just swapping for a 6-50 receptacle is the way I'll go, since I do have the advantage of having an adapter already. I'll keep an eye on temperature and charge at 30A most of the time to extend the life of the adapter. If I ever have problems with it I still have fallback options - either build my own 14-50 to 6-50 adapter cable (thanks for that reminder!), or go back to the HPWC.
 
#15
EarlyAdopter said:
Thanks for the responses everyone!

I had originally planned on using an HPWC, bought one, but sent it back for 2 reasons:
  1. It's big. Really big. At least 4x, maybe 6x, the size of the UMC. Just looked huge holding it up on the wall.
  2. The cord is twice as thick and not as flexible as the UMC cord. It sticks out from the car farther before draping down. I have a tight garage and regularly walk past the car and out the garage door on that side, so it makes a difference.
I don't need >40A charging. I only have a single charger on my current car and the same will be true for future cars, so it would only have been for aesthetics, but after seeing it in person that was out, and for over-engineered margin of safety. On the downside, if the HPWC ever died replacing it will be a pain. With the UMC, if it dies I just unplug it and plug in the UMC from the other car.

As for running a new 6/3 line, it's just going to be a pain. It's fished up inside the wall up and over the ceiling, down the opposite wall, with two 90 degree bends through holes in studs. Perhaps the only thing the electrician did well (heh, well, we'll see on inspection). $100 for new cable plus an hour or two of my time to fish a new cable just to wire up a neutral I'll never need just doesn't compute.

Sounds like just swapping for a 6-50 receptacle is the way I'll go, since I do have the advantage of having an adapter already. I'll keep an eye on temperature and charge at 30A most of the time to extend the life of the adapter. If I ever have problems with it I still have fallback options - either build my own 14-50 to 6-50 adapter cable (thanks for that reminder!), or go back to the HPWC.
Click to expand...

Just found this thread. You should not have to pay to have it fixed. If it were me I would demand they do it right on their dime. You paid for their professional services and that mess up is not professional.
 
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