20 Amp GFCI trips with mobile connector.

[davewill]

This is a very hard thread to follow, partly because the OP insists on using goofy language for the parts he is using, such as 'Magic Plastic'.

I came here looking for info on what is going on with using GFCI on the outlet the mobile connector is plugged into. My understanding is this is part off the NEMA code, so is required, and no way around that. I'm not putting anything in my home that isn't up to snuff.

I can't understand why a pair of cascaded GFCI devices would have any impact on each other. The GFCI is just a toroid transformer core, with both sides of the power line wound through it. The polarity of the windings is such that the two will cancel as long as they are equal. When unequal, a net flux causes current to flow in a sense wire wound on the same core, which can be sensed and used to trip a relay. There is no reason to think having a second GFCI downstream of the first, would cause any problem with operation of either. Yet, I see this reported repeatedly.

I don't see where anyone in this thread explains why this would be a problem. More importantly, I don't see where anyone has a solution.

To the best of my knowledge, all EVSE contain a GFCI, in fact, I believe it is required in the spec. NEMA requires a GFCI in the outlet in locations like the garage. I don't see how EVSE makers can be selling these devices without having problems with them. The only solution would seem to be to not use an outlet, rather direct wire the EVSE.

In general, people DON'T have problems with them. Every now and then, someone comes here complaining that their GFCI is tripping, and we usually just recommend they replace them and that fixes the problem.

The EVSE does a very brief ground test when it powers up, where it passes a miniscule amount of current throught the ground to verify it's connected. It's designed to do this without tripping a GFCI, but if one is very sensitive, it can. Once again, replacement with something newer generally does the trick.

 

[CheapBastid]

More importantly, I don't see where anyone has a solution.

The only solution I've seen so far is a request for me to spend the time/money to 'check the connections' and/or replace a newly installed GFCI 5-20 outlet.

Speaking to the electrician who recently installed that GFCI outlet I was told that they 'don't work with car charging devices', and that 'it is fine'.

So... yeah.

 

[dafish]

 

[davewill]

The only solution I've seen so far is a request for me to spend the time/money to 'check the connections' and/or replace a newly installed GFCI 5-20 outlet.

Speaking to the electrician who recently installed that GFCI outlet I was told that they 'don't work with car charging devices', and that 'it is fine'.

So... yeah.

Well, something's wrong. This works for lots and lots of people. You're going to have to try something different from what you're doing now.

 

[gnuarm]

The only solution I've seen so far is a request for me to spend the time/money to 'check the connections' and/or replace a newly installed GFCI 5-20 outlet.

Speaking to the electrician who recently installed that GFCI outlet I was told that they 'don't work with car charging devices', and that 'it is fine'.

So... yeah.

So, he is saying this is a problem he knows nothing about... yeah.

 

[stopcrazypp]

The only solution I've seen so far is a request for me to spend the time/money to 'check the connections' and/or replace a newly installed GFCI 5-20 outlet.

That's the only remaining thing and most likely cause of your problem. Given your 5-15 GFCI has no issues, it's not your car's power throttling, it's not your 20A breaker tripping, and presumably you have checked you have no other loads on those breakers when charging (I assume those are dedicated breakers, please check if you haven't), there aren't any other obvious possible causes.

Speaking to the electrician who recently installed that GFCI outlet I was told that they 'don't work with car charging devices', and that 'it is fine'.

So... yeah.

Well it isn't "fine", because it isn't working and tripping well under the rated load. Seems like a fairly irresponsible statement. I've worked with electricians on projects and they are more than happy to diagnose nuisance trips and swap breakers as necessary to eliminate them. However, they did a whole house, so it was part of a much bigger job for them. If it was a very small job they may not want to come back.

Technically it's your electrician's responsibility and it's totally understandable if you aren't comfortable doing this if you aren't the DIY type, but it'll take literally minutes to flip off the breakers, use a screw driver to take off the cover plate, and check (if it's backstab or loose)/reconnect the wiring to the outlet. You've probably spent hours already diagnosing other stuff already.

 

[derotam]

Each time it trips the M3LR sets the charging to 48A (max). This is the piece of info that concerns me. I fear that there might be something odd going on, but it may just be standard behavior (an odd standard in my view).

Let me just touch on this because you have brought it up a couple times... I don't think this is an issue because if it was, you would see a problem almost immediately if it went straight to 48A. It doesn't though, the car ramps up the amperage and is continuously doing safety checks. I have seen mine start to go up from 0, and stop part way up, pause, and then continue to max allowed by the adapter that is plugged into the mobile connector.

After reading this whole thread it is looking like you have a faulty or overly sensitive GFCI outlet and would need to change it. People are telling you what they think is the problem and what you can do to check it, or just replace it. If that costs you money that is not our concern, we are not just saying spend more money. Does that part of it suck? Yes. Personally I don't know what the reason for putting in a 5-20 outlet in as an "interim" to getting a 6-50 or whatever else, ESPECIALLY for such a short run and even more especially if this was while you were putting in that sub-panel.

I would also recommend not doing a 6-50, do a 14-50. Negligible price difference for your short run and it is more future proof.

 

[jrmbadger]

first a disclaimer: I'm not an electrician.

I wonder if the shared neutral may be causing the nuisance tripping? Some googling suggests that perhaps the outlets need to be wired in a certain way to make that work (e.g., looks like they have the neutral pigtailed to each outlet rather than connected through the load terminals of the GFCI outlets). See e.g., diy stackexchange See also electrician talk.com

Also, OP, you might want to consider this link here as well: diy stack exchange - In short, it appears that there may be concerns about a shared neutral on single pole breakers like it appears you have.

 

[CheapBastid]

wonder if the shared neutral may be causing the nuisance tripping?

I popped it open, and all wired connections appear to be solid into both (5-15 and 5-20) outlets. So if I remove wire pigtailed from the 5-15 outlet (disabling it as a test) it will effectively leave me with a 'single' neutral. Or might I simply power off the breaker to the 5-15 and achieve (a simpler/neater) result that is similar? A reminder - nothing else is (or ever was) plugged into either (5-15 or 5-20) of these new outlets that might 'cause fluctuations'.

If I can consistently charge at 16A with the 'temporary/rinky-dink' setup that will confirm the 'shared neutral' theory.

If not I can try purchasing (...which I am trying to avoid - see my name for why) another 5-20 outlet. I can try hooking that up to the existing wiring. If that does not work I'm not sure what to do next.

 

[dafish]

So much for trusting your electrician. Those appear to all be back-stabbed. We’ve told you those cause problems. Those need corrected.

what is going on with the white jumper on the “right” receptacle?

Shared neutral line side, as this is, should be no problem.

 

[RayK]

Thanks for the outlet photo. I couldn't find a Leviton part using the number printed on it (11360-078) but at least it appears that the wiring is connected to the screw terminals. If you end up breaking down and replacing the outlet (to get a solid 16A performance), then I would recommend NOT getting another Leviton outlet. For 240V 14-50 outlets, Leviton is known to skimp on the metal that's in contact with the plug blades. That leads to bad connections and increased temperatures. I don't know if that's true with the 5-15/5-20 designs but most people here recommend either a Bryant or Hubbell outlet, but it comes at a slightly higher cost than a Leviton.

 

[RayK]

So much for trusting your electrician. Those appear to all be back-stabbed. We’ve told you those cause problems. Those need corrected.

I looked at the Leviton design. There's screw terminals on the side of the outlet. The white (hot) wire seems to be screwed in (a bit of copper is showing) but I can't determine where the black wire is going.

what is going on with the white jumper on the “right” receptacle?

Good question.

Shared neutral line side, as this is, should be no problem.

 

[dafish]

Cheap, give us a pic from the side. Are the wires connected via screw terminals or back stabbed into little holes?

 

[stopcrazypp]

I popped it open, and all wired connections appear to be solid into both (5-15 and 5-20) outlets

They look backstabbed, as others mentioned. This saves the electrician time and will likely work for smaller loads, but it creates an relatively iffy connection vs using the screws. Definitely not recommended for EV charging (sometimes even the phillips screw method isn't as secure, for example the Hubbell/Bryant 14-50 use a hex screw champ design that allows much higher clamping force).

So if I remove wire pigtailed from the 5-15 outlet (disabling it as a test) it will effectively leave me with a 'single' neutral. Or might I simply power off the breaker to the 5-15 and achieve (a simpler/neater) result that is similar? A reminder - nothing else is (or ever was) plugged into either (5-15 or 5-20) of these new outlets that might 'cause fluctuations'.

If I can consistently charge at 16A with the 'temporary/rinky-dink' setup that will confirm the 'shared neutral' theory.

You can try this first since it requires no work.

If not I can try purchasing (...which I am trying to avoid - see my name for why) another 5-20 outlet. I can try hooking that up to the existing wiring. If that does not work I'm not sure what to do next.

I would redo the connections using the screw terminals before running out and buying a new outlet. Perhaps remove the 5-15 from the loop to eliminate variables.

If you need a tip on how to remove the backstab connection (do not just attempt to pull the wire out, there is a slot where a small screwdriver can be used to release it) here's a video:

 

[CheapBastid]

FYI - they were 'back wired' not 'back stabbed'

Not that I would in any way recommend (or think about doing) this, but there are non GFCI 5-20 outlets that exist, and while not code would sort the temporary issue out (until getting the 6-50 outlets installed).

...so I consider my situation (theoretically) sorted.

 

[Rocky_H]

FYI - they were 'back wired' not 'back stabbed'

That's a new low for this thread. There is no difference between those terms for the same thing.

 

[dafish]

That's a new low for this thread. There is no difference between those terms for the same thing.

Lots of competition for that title, but I offer up "Until getting the 6-50 outlets installed" as runner up.

 

[CheapBastid]

There is no difference between those terms for the same thing.

I am not (and have never been) an electrician. Not sure why I'm continuing to getting a ration of s*** here.

Please see video above. I used the term that the video used. Bitch that guy out.

As I understand it backstab are 'press into' and back wire are tightened down from the back. My new (flaky) GFCI 5-20 had the wires inserted and then were tightened down (by screw, not by some internal backstab mechanism) so they could not be removed without releasing the tightened down screw.

Another video that differentiates.

 

[dafish]

Rocky, I've seen a few of these "back wired" things. Wires tend to pull loose pretty easy so I avoid them, but they do have better connector to wire surface contact than a back stab does. Mind you the other recept seems back stabbed, so...

 

[jrmbadger]

I think eliminating the shared neutral makes sense from a troubleshooting perspective. Another thing to check is to make sure that pigtail wire nut on the neutral is properly tightened. Its hard to tell just from the picture, but I've seem 'em where you can pull out a wire because it wasn't properly tightened. A loose neutral in the wire nut logically would seem to be capable of causing GFCI issues.