I checked again because of you and my mistake. You are right! At work, I use a Leviton Charger 240 v with 30 amp so just use a provided adaptor. So no UMC is needed. I must got confused with NEMA chargers somewhere.
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Intermittent Charging Failure using 120 volt wall outlet
- Thread starter AnesDragon
- Start date
That is what I am trying to do, same as you. Since I have Leviton 240 V 30 amp charger at work and free supercharging rights, I just need to plug into 120 Volt at home. But mine has charge interrupted error that I am unable to overcome as of yet. So far It is not an emergency since I have good access to charging away from work but eventually, I need to solve this problem. I am sure Tesla service will be able to solve this issue. I was just wondering if this was a known issue with a simple solution.
@AnesDragon set the current as low as it will go on the screen when you are parked ready to charge.
Then plug in and see what happens.
Let it go for a while. Watch the voltage.
Increase the current, while still plugged in, and watch the voltage.
It could be an intermittent UMC, but I would bet on a wiring problem.
Tesla May also be able to remotely diagnose, given an exact time of failure.
Then plug in and see what happens.
Let it go for a while. Watch the voltage.
Increase the current, while still plugged in, and watch the voltage.
It could be an intermittent UMC, but I would bet on a wiring problem.
Tesla May also be able to remotely diagnose, given an exact time of failure.
voip-ninja
Give me some sugar baby
Have you plugged into another 120V in someone else's home? Have you tried borrowing someone else's UMC? You should be able to troubleshoot this pretty quickly at a Tesla service center.
There's nothing wrong with charging @ 120V although the efficiency is pretty horrible. You are wasting a lot of power charging that way but I'm sure it isn't more than it would cost you to put a 240V outlet in.
There is no such thing as a NEMA charger. First of all, the charger is in the car, it's not the box you plug into. More importantly, NEMA is the system for identifying electrical outlets. NEMA 5-15 is the usual household outlet, NEMA 5-20 is a 120V 20A outlet, NEMA 14-30 is the 240V 30A dryer outlet, etc. The two UMC adapters that came with your car are for NEMA 5-15 and 14-50 outlets.
Thanks for the info, I've been educated. Never really looked up NEMA just remember that I saw it somewhere. I personally hate acronyms for this reason.
How do you set the current low as you can? I am still a newbie when it comes to Tesla world.
On the charging screen there are + and - buttons to adjust the amperage up and down from the default value that's based on the UMC adapter it detects. (Actually just down, you can't go higher than the default value).
Well, I have an S... but I looked in the 3 manual and it is similar.
Hit the lightning bolt to go to the charge screen (it shows the battery in the middle of the car image).
At the bottom left it shows the charge current. Hit "-" a bunch of times.
Page 114 of the manual.
https://www.tesla.com/content/dam/tesla/Ownership/Own/Model 3 Owners Manual.pdf
The only time I saw that on the Leaf was when there was a power problem at the utility. You might try getting some kind of voltage monitoring device that can record spikes and drops to that plug over time while your charging. I'm sure such a thing exists, but I don't know where to get one. Maybe an electrician or the power company might have such a thing. If the voltage is steady for an extended period than it's probably a problem with charger or the car. One thing you could look at right now is if you have any devices/equipment that cause a sudden heavy draw on the power at your house during the time you're charging. Examples: AC units, electric heat, dryers, heavy duty power tools, vacuum cleaners, etc... those could cause a power fluctuation when they kick off specially if they have a part that is going bad. Also, see if there is another device on that circuit that is under automatic control. You can also buy a power regulator that goes between the plug and your charger if you can find one that is rated for your draw. Another thought, are there any industrial sites nearby that could cause power spikes? Bakeries, shops, aluminium smelters, etc...
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I just noticed this comment. No, Tesla service will not likely be able to solve this issue. Unless you have a bad UMC (possible but unlikely) you will need an electrician at your house to solve this issue. Most likely by wiring a new outlet.
Thanks for trying to help. Although I did finally borrow a friends UMC today and had no problem charging the car for 5 hours in a row to 289 miles at 5mi/hr at 121v and at full 12 amp according to the screen. I was going to charge at my friend's house if this attempt didn't work since he has no problem at his house using 120v outlet at his home with his UMC. I had a feeling it was not my wall outlet issue since my electrical wiring at my house is pretty robust and never had any problems before including a Solar evaluation from Tesla. They stated that I needed 2 power walls and such and that my 2 different electrical fuse boxes also had plenty of bandwidth to deal with the future upgrade.
So anybody with intermittent charge failure should go through the differential of checking the power source such as your wall outlet, and go through the forum members advice such as checking to see the volt and amperage and mileage on your screen and even adjust to lower settings to see if this solves the problem but don't forget it could just be the bad UMC which can be easily distinguished by borrowing someone's UMC. I also heard sometimes even ECU and charge port could be a problem source. It is interesting though to note that most forum members are very protective of Tesla and want to fault the owner's side first rather than the possibility of a defect with Tesla or simply objectively stating the differential of problem-solving in the order of most likely to least likely. Please don't get me wrong but I do appreciate all the help in taking time to help forum members from problems by other forum members like myself.
Glad you found the problem, but I’m sorry you misinterpreted my and other responses as “being very protective of Tesla and wanting to fault the owners side first”. Actually it’s a matter of probabilities and possible dangerous outcomes. We already know it’s not the charge port or otherwise in the car because you can charge with an EVSE at work. The experience of Tesla owners since the Model S came out six years ago is that the problem you described is much more likely to be caused by a poorly wired electrical outlet than be caused by a brand new UMC being defective. Bad outlets are many times more common that bad new UMCs. The dangerous outcome of that could be an electrical fire. So we weren’t trying to protect Tesla, or insult your house that you think has excellent electrical wiring (but how would you know without looking at the outlet?), rather it was trying to tell you what probability says is most likely and trying to prevent a house fire.
teddytoons
Member
Yeah. Just roll up to a Tesla service center. They'll check you in real quick, test the UMC and the car and let you know what happened. The UMC will be under warranty.
Dmagyar
Member
Just a caveat on the level to which anyone’s home has been wired. As a retired Electrical contractor, I recall while going through my apprenticeship, that we were always assumed to be “working” for “chintzy electric”, for any class assignments. My real experience proved during my contracting career, was that all wiring done inside walls and thus not able to be visually inspected is suspect of problems until proven otherwise. I along with many other electrical contractors continue to purchase many pieces of electrical test equipment to help ascertain the condition and viability of any such circuit (not able to be physically inspected).
I agree with you. Solving problems need to occur in a logical manner going through most likely to the least likely causes. Addressing most likely causes will net majority of problems being solved very quickly. However, I bet most of the Tesla owners are some type of enthusiast and likely more educated than the general population on the average because of both the nature of the car and the cost involved. Maybe it is a generalization that should not be made but statistically likely. Most of the time, the owner probably did some due diligence especially when someone points it out in the first place. However, when the majority of the advise just chime in on the same solution to a problem when it was looked into not being a problem that is the bias I was referring to. Even though I was repeatedly stating that my outlet is probably not the issue people seem to "pooh-pooh that", even though they are not familiar with the owner's property. It would be nice to just continue to move on to other differential solutions that you can give due diligence to the problem. As a professional I solve problems every day and like you I think of the most common causes first but always work on differential diagnosis in my mind to make sure I do not miss very important solutions that may cause the outcome to be successful. But I do think you are right to have a good receiving attitude since everyone is taking time out of their day to help people on the forum. I am also an enthusiastic Tesla owner, but I think a lot of improvement still need to be made before Tesla can rule the world. I really don't want them to be a blip in the scheme of things. But thank you for the reminder!
So I called Tesla since the UMC charger is probably at fault and they said they will schedule a mobile service unit to be sent to the house to confirm the diagnosis and replace as well as changing out a lower plastic trim piece that had a deep albeit small gauge by the front driver side door noted during the delivery process. Nice, that I don't have to drive to Rocklin, CA from Reno to have this problem solved. Not having a local dealer is a pain, but having a mobile service is definitely nice! Thanks to everyone who tried to help on this forum.
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