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Voltage too high to charge? (looking for help tonight if anybody is able)

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adiggs

Well-Known Member
Sep 25, 2012
6,422
24,526
Portland, OR
Looking for some help - hopefully tonight if anybody is about.

I am getting a "Charging Problem" error while charging my Roadster 2.5 with the UMC on a 14-50 plug. I know that the plug is on a 30A breaker, but I've got the current stepped down to 12, 16, and 24A and still getting "Charging Problem. ID: 920".

What I've seen when the message shows up is that it seems like the voltage is spiking up around 247V (12 or 16A), or over 240V (24A). I have also noticed that the charging goes longer to failure at 24A (a whole minute or two, instead of 30s at the lower levels).


I've searched the forum and called Tesla - apparently I am the first human, after the programmers that created the error, to have seen it. My operating theory right now is that the voltage is getting too high - for the car, for the UMC - something in there.


Any suggestions?

Asoka

- - - Updated - - -

Some additional detail. The behavior I am seeing is that the car goes through the normal sequence to start charging, ramps up the amps, and begins charging. It charges for a short period (much less than 5 min), and then throws the Charging Problem error. About 1-2s before throwing the error, the voltage cuts in half briefly (and then falls of to zero with the error).

After a few seconds, the error clears on its own, and the car goes back through the sequence of starting a charge, actually starting to charge, and then faulting again.

I was originally in Range mode - it's starting to get chilly here in Valley Ford, so I've switched to Standard mode (not going to get a Range charge tonight anyway) and to keep all the incoming power for the battery (or as much as possible).

After 3 or 4 cycles, the car stops attempting and shuts down charging.
 
Ironically, if you charged at 40 Amp, it would probably work. (You'd have a sufficient voltage drop).

Can you temporarily loan another breaker and switch it around?

Alternatively, do you have a 14-50 extension cord? That would also give you a voltage drop.

Lastly, turn on as many other items on the same supply as you can find (lights, A/C, over, open fridge door etc.) and charge at 24. The current draw may drop the incoming voltage a bit (though it takes a LOT of current to drop voltage on a utility line).
 
Yeah - was thinking about either 32 or 40A. Since I know it's a 30A breaker on that circuit, I figure either of those are doomed to a different problem.

Rather than exploring that, and unlike Tony who carries a selection of breakers with him, I've worked with the hotel and found a 110 to plug into. The car seems to be off and running at 110/15. Not a huge recharge, but I'm about 10 miles from an RV park (Bodega Bay I think he said the name was; near Valley Ford, CA) - it appears I'll be spending a decent chunk of the day with them tomorrow. (I am assuming that my UMC isn't the problem - it's been working fine on a daily basis since I got the Roadster back in March; I'll validate that tomorrow and let the owner of the hotel know once I have some information one way or the other about that plug).


The really unfortunate part of this is that apparently the ID: 920 error is truly new. Tesla Service couldn't find it in their list, I couldn't find it on the TMC forum list of Roadster messages - apparently only me and the programmer of that piece of code have seen it :tongue:
 
Apparently only me and the programmer of that piece of code have seen it :tongue:

Maybe an Easter Egg :).

Not like I would do anything like that. Ever... I would never run a GUID generation algorithm millions of times in a tight loop until I find a GUID that matches my name and initials, and then use it as the identifier of a component that's included by an Operating System used by billions of users. Not even if my initials happens to be writeable in hexadecimal. Never!
 
Good thought DC - I'm not enough of an electrician (read: none) to figure that out or be able to spot that. I've moved up the road and will be getting my overnight charge in Windsor. Sometime later today, I will find a different NEMA 14-50 and validate that it's not my cord / UMC that is the source of the error. I'll be reporting back to the hotel owner either way, and I'll pass along your thought about a bad breaker. Could it be something in the wiring of the outlet? That sort of idea from you is what I was hoping for when I called Tesla Service last night. All I got was a quote from the manual and a page reference, and a check with somebody else leading to agreement that ID: 920 was an error they didn't know :)

If it's a breaker, then they already know they need to update that circuit / breaker to 50A, and the problem probably fixes for free at that point (if you're right). They did have a Model S through there in the last few months and they charged just fine.


So I have my problem solution in hand (charge elsewhere) and the road trip is continuing. Once I have feedback on my cable, I'll check in at Plugshare / Recargo as well.
 
Thanks Lloyd - that's about what I figured (or at least, somewhere above 247). It was the best theory I could concoct on the spot (I'm a software and data guy, not particularly savvy about electricity beyond "don't touch bare wires").
 
Maybe an Easter Egg :).

Not like I would do anything like that. Ever... I would never run a GUID generation algorithm millions of times in a tight loop until I find a GUID that matches my name and initials, and then use it as the identifier of a component that's included by an Operating System used by billions of users. Not even if my initials happens to be writeable in hexadecimal. Never!
lol
 
The high end of the Voltage allowance is supposed to be ~251-252 volts, so I dont think that is the issue.

Correct. I recently charged at 250 - 253 V 70A without any problems with my 2.5. Sure was nice to find that! The fact that it works longer at higher amperage would support deonb's theory that the power supply is dirty and turning on more load from the same panel would help smooth it out. There is a section of Burlington VT where I can't charge my car (or any other roadster 2.5) because something in that neighborhood is creating uneven sine waves with spikes and dips.
 
I just read that there are now Model S HPWC's which supply 277v ! Apparently one phase of the 400v three phase supply. I think that is cool, but I worry about using the S can adapter with such an HPWC. Two problems I see possible. The Roadster probably can't handle that voltage, would it damage the Roadster? Also, in the 110v case, the Roadster is picky about the neutral being on a particular pin, maybe the adapter will not do that? Anyone know more about these 277v HPWC's?
 
I just read that there are now Model S HPWC's which supply 277v ! Apparently one phase of the 400v three phase supply. I think that is cool, but I worry about using the S can adapter with such an HPWC. Two problems I see possible. The Roadster probably can't handle that voltage, would it damage the Roadster? Also, in the 110v case, the Roadster is picky about the neutral being on a particular pin, maybe the adapter will not do that? Anyone know more about these 277v HPWC's?
The Roadster will refuse to charge at 277v as you know. I don't think it will hurt anything but I would avoid plugging into those if you know the voltage is above 250v. The CAN SR has no way to check the voltage but it does keep the polarity correct WRT neutral.
 
I just read that there are now Model S HPWC's which supply 277v ! Apparently one phase of the 400v three phase supply. Anyone know more about these 277v HPWC's?

I think you meant to say that the HPWC can use 277v, not supply 277v. Also, 277v is the line to neutral voltage of a North American 480 volt three phase WYE system (480/sq rt 3=277)