20 Amp GFCI trips with mobile connector.

[jrmbadger]

I'll also offer up that the others are right - if any of those outlets are backstabbed, those are definitely bad. Hard to tell from the pics, but I'll take your word that they are back wired and not back stabbed.

Another thing I noticed is how close those outlets are to each other and how close those live metal terminals are. Is it possible that when you increase the amperage enough, it causes a small amount of stray current on one of the terminals to arc to the other outlet? While perhaps not a safety concern, this might cause an imbalance of hot to neutral on the outlet causing the GFCI to trip.

I mention this because I once had a situation in a house where two romex runs were right next to each other in a wall. A mouse chewed JUST enough of the insulation on both wire runs that when the circuit for one wire run was shut off, I was still getting occasional live current readings on the wire that was shut off with my non-contact voltage tester. Note that the circuits weren't touching one another (and thus I didn't have a short circuit), but were just close enough to cause some stray voltage. In this case, this might be enough to cause the GFCI to trip.

Try wrapping those terminals in some electrical tape to ensure there isn't any stray current bridging that gap.

 

[CheapBastid]

Try wrapping those terminals in some electrical tape to ensure there isn't any stray current bridging that gap.

Will do, thank you for your helpful advice.

 

[FireFighterHil]

Has the electrician checked your panel? I had a similar issue, I finally found the issue was that the previous owner had mixed the neutral and ground bars as well as left a sub panel bonded. I eliminated the sub panel and I put all the grounds on the ground bar only, and the neutral to the neutral only. I also replaced every outlet in the house and made sure they were actually wired to the correct sides, not back stabbed, and all ground tested and connected. It fixed the issue with the afci and gfci popping. I am still chasing down illegal junctions, but i am making progress.

 

[CheapBastid]

Has the electrician checked your panel?

The electrician installed the subpanel (pictured earlier in this thread) a few weeks ago (along with the 'troublesome' NEMA 5-20 outlet).

 

[DuncanM]

The electrician installed the subpanel (pictured earlier in this thread) a few weeks ago (along with the 'troublesome' NEMA 5-20 outlet).

Is there only one outlet on that circuit?

 

[FireFighterHil]

And the sub panel neutral and ground aren't bonded together at the sub panel?

 

[derotam]

The electrician installed the subpanel (pictured earlier in this thread) a few weeks ago (along with the 'troublesome' NEMA 5-20 outlet).

I know this doesn't really matter for your current(no pun intended) problem, but...why did you not just put your intended 6-50 outlet in when the panel was installed?

 

[Rocky_H]

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.

OK, I was wrong on that. I had never heard of or seen that kind of mechanism in an outlet before. I apologize for my incorrect criticism.

 

[gnuarm]

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.

The backstab terminals are shunned by many. Lots of stories of bad connections. I don't like to spread such stories without substantiation, but it's a simple thing to not use. Just use the screw terminals in the way they are intended.

The real issue though, is that the non-GFCI outlet is on a separate circuit from the GFCI outlet. So there's no way the GFCI outlet can protect the non-GFCI outlet.

 

[Cosmacelf]

The backstab terminals are shunned by many. Lots of stories of bad connections. I don't like to spread such stories without substantiation, but it's a simple thing to not use. Just use the screw terminals in the way they are intended.

The real issue though, is that the non-GFCI outlet is on a separate circuit from the GFCI outlet. So there's no way the GFCI outlet can protect the non-GFCI outlet.

Good point. Both are in the garage, where all outlets should be GFCI protected.

 

[DuncanM]

The real issue though, is that the non-GFCI outlet is on a separate circuit from the GFCI outlet. So there's no way the GFCI outlet can protect the non-GFCI outlet.

If this is the case then it would be quite inexpensive to convert the non-GFCI breaker and outlet to a 240v NEMA 6-20 and when paired with a suitable EVSE his car can charge at 240V/16a.

If the EVSE is permanently plugged into the NEMA 6-20 then it's quite safe without a GFCI breaker.

 

[Phil Barnes]

If this is the case then it would be quite inexpensive to convert the non-GFCI breaker and outlet to a 240v NEMA 6-20 and when paired with a suitable EVSE his car can charge at 240V/16a.

If the EVSE is permanently plugged into the NEMA 6-20 then it's quite safe without a GFCI breaker.

I just spent about an hour trying to digest this thread. And I think that THIS (above quoted) is the answer. Let me explain:

From the photos, it looks like there are two 20Amp breakers in the sub panel. These two 20Amp breakers are supplying 120Volts to each of two GFI outlets in the wall box. One of those GFI outlets is a 15Amp, the other is a 20AMP. The single cable running from the panel to the wall box has two conductors (red and black), one white neutral and one green ground.

I think the problem that the original poster is having, is that he is plugging his GFI protected Mobile Connector into a GFI protected outlet. In my experience and what I've heard from electricians: Having two GFCIs In series on the same circuit will cause exactly the behavior being described in this thread. One of the GFIs will trip and shut down the circuit. This thread is the first I've read that suggests that sometimes you can get away with having two GFIs without a problem.

I have two solutions for you:

Solution One
Replace the 20Amp GFI outlet with a 20Amp non-GFI outlet.
Delete the second outlet in the wall box since the charger should have a dedicated circuit.
This 120V, 20Amp circuit should charge at about 7mph.
Only cost here is a 120V, 20Amp non-GFCI outlet (less than $5.00)

Solution Two: as suggested by Duncan M.
Replace both outlets from the wall box with a single 240V, 20Amp non-GFI protected outlet.
Replace the two 20A breakers in the panel with a single 240V, 20 Amp (non-GFI protected) breaker.
This will give you a charging speed of about 15mph.
You would have to buy three things:
240V 20Amp circuit breaker
240V, 20Amp wall outlet
Nema 6-20 adapter for your Mobile connector (the one made for 240V, 20Amp circuits)

As suggested by DuncanM., Solution two would be a simple conversion since the wiring is already in place. Just guessing, the cost for materials would be maybe $100. I would also suggest that a licensed electrician would always put a GFCI protected outlet in place for code reasons. A licensed electrician who installed EV circuits on a regular basis might also tell you to ditch the GFCI outlet (or breaker) and replace it with a non-GFI equivalent after the the inspector was gone.

Finally: The 240Volt, 20Amp outlet with a Mobile Connector is exactly the solution I use for my model Y. My wife has a Wall Connector on the other side of the garage for her Model 3.

 

[stopcrazypp]

I just spent about an hour trying to digest this thread. And I think that THIS (above quoted) is the answer. Let me explain:

From the photos, it looks like there are two 20Amp breakers in the sub panel. These two 20Amp breakers are supplying 120Volts to each of two GFI outlets in the wall box. One of those GFI outlets is a 15Amp, the other is a 20AMP. The single cable running from the panel to the wall box has two conductors (red and black), one white neutral and one green ground.

I think the problem that the original poster is having, is that he is plugging his GFI protected Mobile Connector into a GFI protected outlet. In my experience and what I've heard from electricians: Having two GFCIs In series on the same circuit will cause exactly the behavior being described in this thread. One of the GFIs will trip and shut down the circuit. This thread is the first I've read that suggests that sometimes you can get away with having two GFIs without a problem.

I have two solutions for you:

Solution One
Replace the 20Amp GFI outlet with a 20Amp non-GFI outlet.
Delete the second outlet in the wall box since the charger should have a dedicated circuit.
This 120V, 20Amp circuit should charge at about 7mph.
Only cost here is a 120V, 20Amp non-GFCI outlet (less than $5.00)

Solution Two: as suggested by Duncan M.
Replace both outlets from the wall box with a single 240V, 20Amp non-GFI protected outlet.
Replace the two 20A breakers in the panel with a single 240V, 20 Amp (non-GFI protected) breaker.
This will give you a charging speed of about 15mph.
You would have to buy three things:
240V 20Amp circuit breaker
240V, 20Amp wall outlet
Nema 6-20 adapter for your Mobile connector (the one made for 240V, 20Amp circuits)

As suggested by DuncanM., Solution two would be a simple conversion since the wiring is already in place. Just guessing, the cost for materials would be maybe $100. I would also suggest that a licensed electrician would always put a GFCI protected outlet in place for code reasons. A licensed electrician who installed EV circuits on a regular basis might also tell you to ditch the GFCI outlet (or breaker) and replace it with a non-GFI equivalent after the the inspector was gone.

Finally: The 240Volt, 20Amp outlet with a Mobile Connector is exactly the solution I use for my model Y. My wife has a Wall Connector on the other side of the garage for her Model 3.

The Mobile Connector is designed to work fine with GFCI outlets and breakers. Plenty of people use it that way and it works fine, plus it's required by code, as the GFCI protects the case where you get shocked via the outlet (which the EVSE does not protect against).

 

[Cosmacelf]

I just spent about an hour trying to digest this thread. And I think that THIS (above quoted) is the answer. Let me explain:

From the photos, it looks like there are two 20Amp breakers in the sub panel. These two 20Amp breakers are supplying 120Volts to each of two GFI outlets in the wall box. One of those GFI outlets is a 15Amp, the other is a 20AMP. The single cable running from the panel to the wall box has two conductors (red and black), one white neutral and one green ground.

I think the problem that the original poster is having, is that he is plugging his GFI protected Mobile Connector into a GFI protected outlet. In my experience and what I've heard from electricians: Having two GFCIs In series on the same circuit will cause exactly the behavior being described in this thread. One of the GFIs will trip and shut down the circuit. This thread is the first I've read that suggests that sometimes you can get away with having two GFIs without a problem.

I have two solutions for you:

Solution One
Replace the 20Amp GFI outlet with a 20Amp non-GFI outlet.
Delete the second outlet in the wall box since the charger should have a dedicated circuit.
This 120V, 20Amp circuit should charge at about 7mph.
Only cost here is a 120V, 20Amp non-GFCI outlet (less than $5.00)

Solution Two: as suggested by Duncan M.
Replace both outlets from the wall box with a single 240V, 20Amp non-GFI protected outlet.
Replace the two 20A breakers in the panel with a single 240V, 20 Amp (non-GFI protected) breaker.
This will give you a charging speed of about 15mph.
You would have to buy three things:
240V 20Amp circuit breaker
240V, 20Amp wall outlet
Nema 6-20 adapter for your Mobile connector (the one made for 240V, 20Amp circuits)

As suggested by DuncanM., Solution two would be a simple conversion since the wiring is already in place. Just guessing, the cost for materials would be maybe $100. I would also suggest that a licensed electrician would always put a GFCI protected outlet in place for code reasons. A licensed electrician who installed EV circuits on a regular basis might also tell you to ditch the GFCI outlet (or breaker) and replace it with a non-GFI equivalent after the the inspector was gone.

Finally: The 240Volt, 20Amp outlet with a Mobile Connector is exactly the solution I use for my model Y. My wife has a Wall Connector on the other side of the garage for her Model 3.

The Mobile Connector works fine with properly functioning GFCIs. We asked several times for the OP to just replace the dang GFCI and as I recall he hasn't so ???

I am getting annoyed at people repeating what is now an old wives tale that EVSEs do not work reliably with GFCIs. This requirement is IN THE NEC!!!! The NEC isn't going to make such a dumb mistake.

 

[flai54]

Can you be more specific than "plugged into a converter", "standard adapter" and "reduced to a level that I've never seen at home"?

Exactly what type of "converter" are you using?

The standard adapter provided with the mobile connector is a NEMA 5-15; what looks like any other 120VAC plug that you have in your home. Two blades, one slightly thicker than the other and a round ground pin:
View attachment 961422
The NEMA 5-20 plug is this:
View attachment 961423

The maximum current that the 5-15 adapter will allow is 12 amps. The maximum current that the 5-20 adapter will allow is 16 amps. What was the amps that you have "never seen at home"?

Note that using the mobile connector on a circuit which is protected by a GFCI can be problematic. Some people have absolutely no issues with this setup. Others trip the breaker at random times.

Even then ....setting it to 16 amps is only suitable if that is the only outlet connected to the breaker in the panel. If this is connected to another outlet you run the risk of overloading it.

 

[Hotwheelzz]

Have had the Tesla Mobile Connector plugged into a converter to then plug into a standard GFCI outlet that has a cover outside that was feeding a fountain.

We're in the process of re-doing our carport and will eventually get a 6-50 plug on a 50amp breaker installed, but in the interim they have put in a 20amp GFCI plug that will take the Tesla Moblile charger wihtout the 'standard adapter' to 'dumb it down' to a 15 amp plug.

I was ecstatic as the mobile connector would reduce the charging voltage and it was super slow. Once I plugged it into a native 20 amp outlet with a dedicated breaker the charging estimate reduced to a level that I've never seen at home.

Once I got into the house the GFCI tripped. I thought it was fluke and re-set the plug but I noticed the car was setting the charge rate to 48 amps.

Since then I've been dancing with the charging settings in the car, trying to limit the rate to 16 amps, but I haven't been successful.

Last night I thought I was safe, walked away, check it twice, set to 16 amps.

Two hours later (after we were asleep) the GFCI tripped again.

Any suggestions on something I might be missing?

 

[Hotwheelzz]

Have had the Tesla Mobile Connector plugged into a converter to then plug into a standard GFCI outlet that has a cover outside that was feeding a fountain.

We're in the process of re-doing our carport and will eventually get a 6-50 plug on a 50amp breaker installed, but in the interim they have put in a 20amp GFCI plug that will take the Tesla Moblile charger wihtout the 'standard adapter' to 'dumb it down' to a 15 amp plug.

I was ecstatic as the mobile connector would reduce the charging voltage and it was super slow. Once I plugged it into a native 20 amp outlet with a dedicated breaker the charging estimate reduced to a level that I've never seen at home.

Once I got into the house the GFCI tripped. I thought it was fluke and re-set the plug but I noticed the car was setting the charge rate to 48 amps.

Since then I've been dancing with the charging settings in the car, trying to limit the rate to 16 amps, but I haven't been successful.

Last night I thought I was safe, walked away, check it twice, set to 16 amps.

Two hours later (after we were asleep) the GFCI tripped again.

Any suggestions on something I might be missing?

Has anyone given an "official" reason why Tesla chargers will trip some GFCI? I park at a place where no other EV will trip the outlet, except Teslas. It is becoming extremely annoying and unreliable. Thanks

 

[stopcrazypp]

Has anyone given an "official" reason why Tesla chargers will trip some GFCI? I park at a place where no other EV will trip the outlet, except Teslas. It is becoming extremely annoying and unreliable. Thanks

You would have to define what you mean by "no other EV". Do you mean another EV plugged into the Tesla Mobile Connector would not trip, but a Tesla would? If so, how much power is that EV drawing vs your Tesla? If that EV is drawing less power, what happens when you set your Tesla to the same power?

Or do you mean another EV plugged into a different EVSE? If so, which EVSE model, and how much power is that EV drawing? If that EVSE works, what happens when you plug that EVSE into your Tesla?

 

[Hotwheelzz]

You would have to define what you mean by "no other EV". Do you mean another EV plugged into the Tesla Mobile Connector would not trip, but a Tesla would? If so, how much power is that EV drawing vs your Tesla? If that EV is drawing less power, what happens when you set your Tesla to the same power?

Or do you mean another EV plugged into a different EVSE? If so, which EVSE model, and how much power is that EV drawing? If that EVSE works, what happens when you plug that EVSE into your Tesla?

No other EV, except Teslas, was meant to say that for that same 20amp GFCI outlet, only the Tesla mobile chargers are tripping the outlet. No other EV brand is tripping the outlet, and that includes hybrid plug ins as well. I do not know how much those EV's are drawing. I have personally tried multiple amperages, such as 8,10,12 and 16amps, and all tripped the outlets. However, there is a section of "older" power outlets that don't trip (kind of in the opposite side of the garage). I can't tell if it's because the power outlet is old, it may not be as sensitive as the new outlets (Both old and new are GFCI's). I've heard claims that Teslas will leak a bit of power through the ground wire, in order to verify the integrity of the ground connection, but I'm not sure if that is a fact or not. My question is. Is that in fact the case for Teslas? Is there a way to mitigate the issue? Any suggestion? Thanks everyone.

 

[Cosmacelf]

I've heard claims that Teslas will leak a bit of power through the ground wire, in order to verify the integrity of the ground connection, but I'm not sure if that is a fact or not. My question is. Is that in fact the case for Teslas? Is there a way to mitigate the issue? Any suggestion? Thanks everyone.

I'm 99% sure that it is a fact that Tesla leaks a bit of power to verify there is a working ground. It is supposed to do it either quickly enough or low enough current to not trip a functioning GFCI. GFCI's tripping can be cured by simply replacing the GFCI outlet. GFCI outlets are notorious for having a limited lifespan (like 5 years typically).

I don't see a work around unless you want to do some handyman work in the garage...