stopcrazypp
Well-Known Member
Did they try replacing ONLY the 14-50 adapter? That can isolate the problem instead of guessing which part it is. The other case, that was the problem.
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New 240v outlet pulling 0 amps
- Thread starter toki
- Start date
The car reports 240V so L1-L2 are fine.
Neutral isn't used.
UMC thinks ground is OK.
Hardware works fine on 120V which uses the sane power wires.
14-50 also fails at Tesla.
Adapter is passive pass-through as regards power connections.
Agree about the neutral. But, in the interests of chasing things down and looking at possibilities, I wonder about that ground.
Suppose there was a low-impedance connection to one of the hots on that ground in the socket. There'd still be 240 VAC across the hots. But.. 120 VAC or 60VAC or something idiotic on the ground pin.. could it blow out a resistor or wire somewhere, leaving the ground, well, kind of floating around?
For that matter.. safety ground goes to ground somewhere. Neutral, not quite. That is, Neutral is supposed to be connected to the ground/neutral bus bar in the main breaker box. And, if one is in a residential house, that's often the case. An AC voltmeter connected between the neutral pin on a plug and the ground pin usually shows near-zero voltage when there's no load, and a couple of volts of I-R drop when there is a load. One might see this, say, on an unused 120 VAC socket when the other socket has a running vacuum cleaner or light plugged into it.
However, in my years of Just Messing Around, I've checked the voltage between neutral and ground in industrial-style buildings I've inhabited. And, interestingly, while there might be 120 VAC between hot and neutral, there was atypically (to me, anyway) anywhere between 0 and up to 50 VAC between ground and neutral.
And then there's the question about whether the house's grounding is proper. In modern construction there's usually a great big green wire that goes from the main breaker panel's ground/neutral bus bar, outside of the house, and bolted to a 6' copper ground stake that's been pounded into the ground. But I've been in much older houses where said green wire was more-or-less haphazardly attached to a copper cold water pipe.
And then there's been the extraordinary stuff I've run into as part of my work in telecom. The most notable, I suppose, where a really thick "grounding" wire ran from inside of a shielded shack, through a hole in the wall, onto a tray, 50' over to a gol-dang 200' telecom tower, up 70' on the telecom tower, and then firmly attached to one of the galvanized steel uprights. And said telecom tower was the highest thing in the neighborhood, by far, and was subject to lightning. Uh. No. Even if the base of the tower went to some serious ground stakes. One violates the Faraday Cage approach at one's peril. (I got pictures, even!)
So, I tend to be suspicious of grounds and weird errors. And I've seen enough smoked hardware to be really suspicious.
Agree things are weird, but the UMC handles 120V L1/L2 to ground normally and I expect 240V L1/L2 to ground would be survivable. Especially since miswired 208 Wye outlets are a thing.
The panel end of the feed would need to be severely misconnected since L1-L2 show 240V, so to get line on ground requires another breaker connection of the wire connected to the ground pin. And then it would need to somehow pass the UMC's ground test.
To me, the failure mode points to everything working except for the car knowing what the current limit is.
Took the "new" UMC to the alternate location (tested 2 separate outlets) and showed the typical 0/0amps. Same at the house
Shot the outlet at the house again and reads as follows (dryer is running, so a bit of a voltage drop):
L1 - G = 121.5v / OLΩ
L1 - N = 121.3v / OLΩ
L2 - G = 120.1v / OLΩ
L2 - N = 119.9v / OLΩ
L1 - L2 = 241.9v / OLΩ
G - N = .035v / 0.0Ω
Shot the outlet at the house again and reads as follows (dryer is running, so a bit of a voltage drop):
L1 - G = 121.5v / OLΩ
L1 - N = 121.3v / OLΩ
L2 - G = 120.1v / OLΩ
L2 - N = 119.9v / OLΩ
L1 - L2 = 241.9v / OLΩ
G - N = .035v / 0.0Ω
ATPMSD
Active Member
You may wish to also pull the outlet and verify all connections are tight and there is no charing. Then do the same in the breaker box, including the N & G wires.
Verified. All connections are good and no charing or melted insulation.
Told Tesla SC that the same issue is going on and they said to call an electrician. I don't feel like I need one since I feel like they're just going to check what has already been checked numerous times, but am willing to get one out here for good measure.
I wish I could just pull my car into the house and plug it into the range outlet and see if it works there.
It wouldn't make sense that 4 different outlets aren't working properly.
fholbert
Active Member
@CosmicBrownMan ,
If you pull the outlet, suggest you replace it with something better than a Home Depot outlet.
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davewill
Active Member
I agree that having it fail at the other locations is strong evidence that it's not your outlet. That said, having someone out to check it may be the only way to satisfy Tesla to take it to the next step. I'm afraid very little of the troubleshooting so far makes much sense.
That said, I wouldn't plug it into your house at all at this point. It will just encourage Tesla to continue to point the finger at your outlet.
I wonder if the problem could be upstream of the ECU, at the internal charger itself?
Yeah, doesn't make sense given it didn't work at Tesla either.
Was there any strange order of operations when the second UMC worked at Tesla? Like it started out plugged into the car. Car started out asleep. Anything like that?
If you knew someone with a 14-30, that would be an interesting, but not worth the cost of adapter and outlet just to test it...
I know I'm stretching, here, and am probably wrong. But check and make sure that the connection between the ground/neutral bus bar and the physical ground outside is in good working order. As I've said before, this is usually set up by a thick copper wire with green insulation that, at one end, is bolted to the ground/neutral bus bar in the breaker box. It then exits outside of the house somewhere, usually down low, and is physically clamped to a copper bar, pounded very thoroughly into the physical ground. These copper stake ends can sometimes be a bit hard to find since, after years of plant growth and mulch addition they tend to get buried a bit. That, and when they get installed, in the interests of not having a lawnmower find them, they get pounded down flush with the ground or deeper. But one can usually spot the green wire, somewhere down below the electric meter on the outside of the house.
Sometimes that little clamp rots.
I honestly don't know what a floating ground hooked up to neutral might do. But telephone poles are subject to Big Static Discharges, which makes everything bounce around. Even short of an actual lightning strike. Part of the reason for that ground bus bar to Actual Ground connection is to keep that kind of junk under control, on a neighborhood-wide basis, if you see what I mean.
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My brother-in-law has a Tesla and a 14-50 in his garage. Think I'll drive up there and try his charger out, see if it works, then my charger.
I wasn't out in the garage when they tested it. Should have been through.
No dice. He has a 14-30 plug, and just sold his Tesla and adapter. Sorry to get everyone's hopes up haha.
Checked the connection to the ground rod and it is fine, the house is only a few years old.
Pretty quick to spend other people's money haha.
I did not install a breaker with a GFCI, could run up and grab one, but I also don't think that'd cause this. At least without a fault showing on the UMC.
GFCI would only make things worse.
Not gonna let you waste your money!
davewill
Active Member
I agree. Yes, you should have installed one, but not having it won't cause the problems you're seeing, and unnecessary changes should definitely be avoided at this point. Same thing with putting in a "better" outlet. A cheap outlet isn't going to cause the problem you're seeing, and changing it now won't help. A cheap outlet might get hot and throttle down after charging for a while, but it won't act like you're seeing.
ATPMSD
Active Member
I would be suspicious that Tesla actually tested it as I don’t think they have 14-50 outlets, so then probably just tested the 5-15 adaptor and at one of their wall connectors. Testing at your brother-in-law is an excellent idea!
I don't think that's true. I've seen many many many reports over the years of Tesla service centers testing people's UMCs on 14-50 outlets at the service center. Since that was the most common method for people charging at home for many years, it made sense for them to make sure to have at least one 14-50 outlet available at every service center to use for basic troubleshooting. So yes, it seems pretty common for them to have one for testing.
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