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Gen 2 charger ground faults

boilerbots

Member
Apr 4, 2013
62
3
San Jose, CA
i have a Model S with a gen 1 charger and have never had ground faults. I am getting ground fault errors, 1 flashing red blink, maybe 50% of the time after connecting to charge. I plugged the charger into the same outlet as my S and it still happens.

Anyone had a problem like this and found that it was the adapter and not their home wiring?
 

Need

Active Member
Nov 22, 2017
2,882
2,196
SoCal
Is that what that is called? Flashing red light on the mobile unit... a ground fault? We got it all the time when we first got our MX (that comes with the Gen 2 UMC). I would have to unplug it, plug it back in and it would be okay for next charge. But just about every time the charger comes out from the port and put it back it.. got the flashing red lights.

After a few days, we called Tesla and they came out and replaced the Gen 2 with a Gen 1. Now it never ever flashed red again.. been over a month now. And it also charges faster. :D
 

run-the-joules

Active Member
Aug 13, 2017
3,644
6,517
SF Bay
Ooooh, this is happening to me too. If I plug into the car and then the wall, it's fine. Wall and then car… roll of the dice. Was going to bring it with when I take the car to get the heater checked, but having them send a ranger isn't a bad idea.
 

cwerdna

Active Member
Jul 11, 2012
3,399
2,241
SF Bay Area, CA
i have a Model S with a gen 1 charger and have never had ground faults. I am getting ground fault errors, 1 flashing red blink, maybe 50% of the time after connecting to charge. I plugged the charger into the same outlet as my S and it still happens.

Anyone had a problem like this and found that it was the adapter and not their home wiring?
What do you mean by "charger"? For level 1 and 2 AC charging, the charger is on-board the car. See Range issues - Page 2 - My Nissan Leaf Forum.

For the L1 and L2 AC cases, the external unit (e.g. Tesla Product Page Template and Model S/X/3 Wall Connector) are EVSEs, NOT chargers. Notice Tesla calls them connectors and not chargers?

You having a problem w/the mobile connector or wall connector as opposed to the car's on-board charger?
 

DFibRL8R

Active Member
Jan 17, 2013
1,286
1,796
Leesburg Virginia
I’ve been having problems with my new UMC/EVSE that came with the Model 3. I have been using it to charge the Model S on a 110 outlet (using the Model S Charger on a 14-50 for the new Model 3 since it has a higher charge rate). I’m getting frequent Red charge ring light. Oddly the steady Red ring flashes blue briefly then back to steady red. Unplugging the UMC from the wall seems to reset and it works again, for a short time.
 

boilerbots

Member
Apr 4, 2013
62
3
San Jose, CA
Sorry to call the wall adapter thing a charger, I dumbed my question down to much. I meant the “mobile connector”.

So it seems a few others are seeing the frequent faults. I should probably contact Tesla and see what they say considering the gen 1 has never faulted on the same outlet over 5 years.
 

Need

Active Member
Nov 22, 2017
2,882
2,196
SoCal
Sorry to call the wall adapter thing a charger, I dumbed my question down to much. I meant the “mobile connector”.

So it seems a few others are seeing the frequent faults. I should probably contact Tesla and see what they say considering the gen 1 has never faulted on the same outlet over 5 years.

Yeah you should. They will probably just exchange it with a good one. There was another thread in the Model S forum that a new MS owner got the Gen 2 UMC and having the same problem. Maybe there is a bad batch of Gen 2 UMC out there.
 

EdinSD

Member
Apr 12, 2018
6
2
San Diego county
I see this is the Model 3 forum, but we got a new Model S a month ago with a Gen 2 cable, and are having the exact same issues. It always works if I plug in to 110. On 240, mostly it errors with the ground fault code. I usually fix it by flipping the breaker on the house panel off and back on again. Sometimes just unplugging it from the wall and plugging back in works.

I had our electrician out to double check his work. Of course it didn't error out when he was here! Then the Tesla ranger guy came out and gave us a brand new Gen 2 cable. It worked when he was here, but then later, the error code again.
 

Ted209

New Member
Mar 13, 2018
3
0
California
I'm on my third Gen 2 mobile connector for my new Model S and I get a ground fault error about half the time I plug it in. I usually disconnect the cable, then pull out the connector out of the socket and back in again (wish there was a reset button) and there's about a 50% chance of success. Sometimes I need to do this half a dozen or so times to make it work. My previous Model S never had this problem with the Gen 1 mobile connector
 

Karma

Member
Nov 17, 2014
104
15
Safety Harbor, Florida
Glad to see that we are not the only ones. I never had an issue with the Model S. Model 3 is a different story. 50% of the time the car fails to start charging, or starts, then faults. If I unplug from the 14-50 and replug to the outlet, it seems to to work. Major PITA, if you ask me, but even more so for my wife, who isn't as used to waiting to make sure that charging has started (and not terminated due to fault).
 

TexasEV

Well-Known Member
Jun 5, 2013
7,642
8,470
Austin, TX
I’m also on my 3rd gen 2 UMC. The one that came with the Model 3 was replaced because the buttton didn’t depress easily, The replacement UMC had ground fault errors about one time in 5 that I plugged it into the charge port. The next replacement has worked fine for the past few days.

In contrast, the UMC that came with my Model S five years ago lasted for 4 years. And that was supposed to be the less robust than Gen 2 because it charged at 40A.
 

sunnyg

Member
Mar 22, 2018
7
0
Bay Area California
OMG I'm so glad I found this page... I've been splitting hairs trying to figure this out. I'm on my second generation 2 charger and it's still showing ground fault even though the certified electrician that installed the 240v outlet proved to me that everything was installed correctly with a meter. This thread seems to confirm for me that there is something wrong with the UMC and not the outlet that works half the time. Has anyone had luck after getting the UMC replaced multiple times? Also I'm on the new Mcu.
 

TexasEV

Well-Known Member
Jun 5, 2013
7,642
8,470
Austin, TX
When the service center plugged my gen 2 UMC into their 240V outlet to charge my car with it, it gave a ground fault one time out of the 10 times they tried it. So they knew it was the UMC, not my outlet, but the problem with diagnosing such an intermittent issue is they need to try it many times to reproduce it. The replacement UMC has worked fine at home.
 

McBtes

Member
Aug 30, 2017
5
0
UK
I have had this problem and the answer for me is to put a hose on the ground spike .... with v dry weather, the soil pulls away from the spike. Put water on on (for 20 mins or so) and it works.
 

eprosenx

Active Member
May 30, 2018
2,065
2,484
Beaverton, OR
I have had this problem and the answer for me is to put a hose on the ground spike .... with v dry weather, the soil pulls away from the spike. Put water on on (for 20 mins or so) and it works.

If this is truely what is making your charging work then you have a SERIOUS issue with your electrical system and you need to have an electrician out right away.

What an EVSE is testing for is *not* that your ground is connected to earth. It is really testing to make sure your ground and neutral are bonded together. It is checking for voltage potential between the hot conductors and the ground. Whether ground is actually connected to the earth is not something it can test for.

If what you describe is true, then it sounds like your house does not have neutral and ground bonded and you are relying on the earth providing a conductor from your ground rod back to the utility transformer.
 

geometro

Member
Jun 24, 2015
370
530
Austin
Mine started acting up last week too. The mobile charger shows the letter “T” in red (rather than green).

When I called up the service center, they said it was the outlet. How do I get them to replace the mobile charger?

(It went away after I unplugged the charger and plugged back in; just happened again this morning though).
 

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