Problems charging at 110v on GFCI circuit

[jimmyz80]

Glad the information was helpful. I figured Eaton GFCIs would be good quality stuff, since usually Eaton gear is pretty top notch. I suspect the Gen 1 UMC did test, just less aggressively or something. The same Chinese GFCI I had problems with on the Gen 2 UMC, would also pop when trying to charge my Roadster back when I had it. I suspect the new Eaton GFCI would have probably fixed that situation as well.

 

[mswlogo]

I had a similar problem with a new variable speed DC brushless pool pump tripping the GFCI. Nothing to do with water or excessive load.

The way GFCI’s work is there is a circuit that has a frequency associated with it. The new Pump is a huge 3HP variable speed DC brushless motor. So it has a AC to DC inverter in it. It also has an inherent frequency in its circuits.

The two frequencies clashed. And it would trip after hours of running fine. And sometime it would trip when the electronics booted (without the pump even being on).

All I had to do was use a different brand GFCI. I had a Murray panel with Murray breakers. Siemens bought Murray. So I installed a Siemens beaker (it looked 100% the same). But it uses a different frequency. The electrical supply folks knew exactly the problem and said the Siemens will fix it. It did. It was not a defective breaker that was working perfectly on the old AC 2HP conventional pump.

I would try another brand circuit breaker (or GFCI outlet). And I’d do a little research on the old vs new brand to be sure they are different. A lot of stuff these days are made by one manufacturer that is labeled by many companies.

You are not plugging in an incandescent lightbulb here

If getting the outlet changed is out if your control you might be able to “buffer” it some how. Like through a power conditioner.

Oh, for grins, try plugging in say a 60 watt incandescent light bulb into the same socket while it charges.

 

[TurnFast]

Well crap, I had been just charging my car at work but I went to charge at home last night and exactly this happened where it kept tripping the gfci outlet in my garage.
I guess I need to get new gfci outlets? That seems to have solved the issue for most people?

 

[eprosenx]

Well crap, I had been just charging my car at work but I went to charge at home last night and exactly this happened where it kept tripping the gfci outlet in my garage.
I guess I need to get new gfci outlets? That seems to have solved the issue for most people?

Yes, try replacing the receptacle that is tripping first and see what happens.

 

[Feathermerchan]

ponzu - I am charging from the ceiling outlet in my garage. With GFCI. No problem except that I cannot reach to plug it in without a ladder. I found a 12ga 3ft extension at Lowes. It does not get hot at all and allows me to reach up and plug the EVSE in easily..

 

[ka9q]

That's not really how GFCIs work. In normal operation, all of the current that comes out of the line pin on the plug returns through the neutral pin. When a ground fault occurs, some of that current doesn't make it back to the neutral, and this causes an imbalance. A GFCI senses that imbalance, and if it is greater than just a few milliamps, it removes power.

The actual implementation is pretty clever. The line and neutral wires (black and white in North American practice) but not the ground wire are run through a magnetic core shaped like a donut. A sense winding is also wound around the core. If the currents in the line and neutral wires are exactly equal and opposite as they should be, their magnetic fields cancel in the core and no current is induced in the sense winding.

One reason for nuisance trips of GFCIs are radiofrequency interference filters built into devices with switching power supplies (which is just about everything these days). They include capacitors that shunt the radiofrequency noise onto the ground wire. If these capacitors are too large, they'll pass enough current to reach the trip threshold of a GFCI.

Another cause are devices that simply generate too much radiofrequency noise that isn't properly filtered. GFCI sense circuits are pretty sensitive, and if they don't filter out radiofrequency noise from a load it can also cause nuisance tripping. This is probably what's happening with your large pool pump; variable frequency motor drives can generate a lot of noise if they're not properly filtered.

 

[zafirisj]

This happened to me for over 1 year. It was quite frustrating and I called in the business electricians and they could not resolve it.

I discovered a remote iPhone thread claiming that the Tesla app was draining their iPhone battery. This was caused by the app remotely waking the car repeatedly. The contention was also that a power spike was triggered when the car was being wakened by the Tesla app.

I then recalled that the electrician reported that a power spike was being triggered by the car and causing the GFCI to trip.

I have been logging off my app on the iPhone immediately after I start charging and I no longer have charging problems.

Give it a try.

 

[jdbunda]

Ran into this exact issue with my new Model 3. First few nights it charged just fine on 110v, then suddenly, it started popping the GFCI. I saw a few threads on this, figured the GFCI was 20 years old or so. I got a new Leviton GFCI at HD, replaced it, but still the same issue. I took my car and charger to the Tesla service center, they tested everything and no issues, so it's my house setup. I ordered one of the Eaton GFCI outlets, and will give that a try. Hopefully I will get my 220v outlet installed quickly and all of this will be moot. I plan to try an extension cord to one of my other outlet circuits that isn't on a GFCI later today. Interesting about the iPhone app, will give that a try too, but I don't think it's that as it always trips my GFCI immediately on charger connection. I still think it's weird that it worked fine for a couple of days, then suddenly started.

 

[jdbunda]

Postscript to the above - I replaced the Home Depot Leviton GFCI outlet with the Eaton one from Amazon as recommended above, and all is good, my car charges without issues..

 

[mswlogo]

That's not really how GFCIs work. In normal operation, all of the current that comes out of the line pin on the plug returns through the neutral pin. When a ground fault occurs, some of that current doesn't make it back to the neutral, and this causes an imbalance. A GFCI senses that imbalance, and if it is greater than just a few milliamps, it removes power.

The actual implementation is pretty clever. The line and neutral wires (black and white in North American practice) but not the ground wire are run through a magnetic core shaped like a donut. A sense winding is also wound around the core. If the currents in the line and neutral wires are exactly equal and opposite as they should be, their magnetic fields cancel in the core and no current is induced in the sense winding.

One reason for nuisance trips of GFCIs are radiofrequency interference filters built into devices with switching power supplies (which is just about everything these days). They include capacitors that shunt the radiofrequency noise onto the ground wire. If these capacitors are too large, they'll pass enough current to reach the trip threshold of a GFCI.

Another cause are devices that simply generate too much radiofrequency noise that isn't properly filtered. GFCI sense circuits are pretty sensitive, and if they don't filter out radiofrequency noise from a load it can also cause nuisance tripping. This is probably what's happening with your large pool pump; variable frequency motor drives can generate a lot of noise if they're not properly filtered.

Thanks for the detailed explaination. I knew it had to do with noise from the switching circuits erroneously getting into the GFCI sensing. But didn’t understand technically the reason why one GFCI was susceptible and another not other than it was frequency based. Are you saying the one that works just has better filtering or is it that different venders target different frequencies to filter?

 

[ka9q]

Are you saying the one that works just has better filtering or is it that different venders target different frequencies to filter?

Could be any of those things; I wouldn't be able to tell without some testing with the right equipment.

 

[Jeffers0n]

For anyone still following this thread, I had a similar problem in my garage. My UMCv1 from my Model S worked just fine on my GFCI garage outlets, but the UMCv2 from my Model 3 would pop them instantly. They were no-name Chinese junk from the home builder, and I just replaced them with these Eaton GFCI outlets, which seem to have totally resolved the problem. I plugged and unplugged the UMCv2 at least a dozen times and the GFCI never popped a single time.

https://www.amazon.com/Eaton-Self-Test-Resistant-Receptacle-Wallplate/dp/B0189B79IM/

Just wanted to say thank you sooo much. Had the exact same issue as this thread and ordered the Eaton GFCI that you linked to on Amazon. Worked 100%. So happy to be able to charge my car at home now (was starting to freak out since charge level was getting low and was getting vampire drain over the holidays).

 

[TallyGator]

I had the problem with the wall charger tripping my rented garage's 110V GFCI outlet. I tried logging out of the app, but it did not solve the problem.

I'm pleased to report that the Eaton GFCI outlet recommended on this thread works very well! I've not had it falsely trip for over a week now.

 

[Rocky_H]

I had the problem with the wall charger tripping my rented garage's 110V GFCI outlet.

I am rather puzzled at how you have a wall connector wired to use a plug on a 120V outlet. It's not intended to be used on a 120V circuit.

 

[davewill]

I am rather puzzled at how you have a wall connector wired to use a plug on a 120V outlet. It's not intended to be used on a 120V circuit.

I presume he was referring to the mobile connector.

 

[Feathermerchan]

Esp because he used 'charger'. They are not chargers.

 

[TallyGator]

I should have written mobile connector. My mistake!

 

[Feathermerchan]

There you go. Words are important.

 

[mtlake]

I resolved my issue but thought I'd pass this on.

I had been charging my Model 3 on a garage downstream 110v GFCI outlet for several weeks. After driving longer than I usually do (a few miles per day) and plugging it in, after charging to 198 miles, I was notified it stopped charging due to an issue. This happened a few times, then I smelled something inside the house. After a little investigation, I found the GFCI outlet was seriously melted inside the box. I plugged the car into a non-GFCI outlet and no problems thereafter. The outlet that melted was not the one that the car was plugged into, it was one of several downstream from the GFCI breaker which never tripped. The other load on the circuit was minuscule (< 1 amp). The circuit was a 20 amp with a 20 amp GFCI. The adapter for the charger is the standard 110 that ships with the car so it should only have been drawing 13 amps. Don't know if this has anything to do with GFCI but I'm staying away from such circuits when possible.

 

[eprosenx]

I resolved my issue but thought I'd pass this on.

I had been charging my Model 3 on a garage downstream 110v GFCI outlet for several weeks. After driving longer than I usually do (a few miles per day) and plugging it in, after charging to 198 miles, I was notified it stopped charging due to an issue. This happened a few times, then I smelled something inside the house. After a little investigation, I found the GFCI outlet was seriously melted inside the box. I plugged the car into a non-GFCI outlet and no problems thereafter. The outlet that melted was not the one that the car was plugged into, it was one of several downstream from the GFCI breaker which never tripped. The other load on the circuit was minuscule (< 1 amp). The circuit was a 20 amp with a 20 amp GFCI. The adapter for the charger is the standard 110 that ships with the car so it should only have been drawing 13 amps. Don't know if this has anything to do with GFCI but I'm staying away from such circuits when possible.

So I don’t think this had anything remotely to do with the GFCI nature of the circuit.

I think quite simply something was not tightened sufficiently (or was a defective receptacle - which is unlikely). When wires are not tightened properly and carry sufficient current they can heat up massively and melt things.

Most residential circuits are daisy chained one receptacle to another. So if you are charging the Tesla on the fifth receptacle in the chain you are running he current through four other receptacles and you are relying on all those connections to be made properly.

This is one reason why NEC requires EV charging circuits to be dedicated (for a any new circuits you install).

Note that a GFCI receptacle or circuit breaker only protects you from faults to ground. In this case there was likely no fault to ground (just excessive heating which eventually caused enough voltage drop for the Tesla to detect an issue and maybe save you from a house fire). The regular over current function of the circuit breaker also would not have tripped since current levels likely were not out of spec.

If at all possible I would recommend installing a dedicated charging circuit (and perhaps upgrade to 240v and maybe higher amperage at the same time!)