Had the electrician replace the GFCI breaker at the box with a fresh GE 20A after the origional was tripping. The circuit shares 2 bathrooms (with gfci plugs in each) and the car is set to charge at midnight when nothing else is on the circuits. I'm getting a trip at the breaker GFCI maybe once a week or 10 days and charger is set to full power. Seems to be near the end of the charge cycle since the car is at 75% in the morning when it tripped. Guessing I need the fancier GFCI breaker and hoping an expert can chime in since my googlefoo is lacking. TIA!
I dont and not sure how I'd determine that. The breaker has a red indicator that goes away after flipping the breaker itself off and then back on. The breaker lever itself is not tripped over, its just showing a red indicator so my guess is GFCI fault and not over-current. There's nothing else running on the line at the time either.
it does sound like ground fault, maybe the old one wasn't bad. i suppose these are some of the reasons for a dedicated circuit.
The old one tripped almost every time. I've read that receptacles can get old and causes problems and this is an outside socket that is probably original to the 20+ year old home. Thinking the solution may be a combination of a new socket where the charger plugs in and one of the charger friendly GFCI breakers that I cant seem to find the name of.
I've had my charger plugged into a 15A circuit and outlet (protected by an ordinary daisy-chained GFCI outlet, not a GFCI breaker) and it has never tripped once.
Is it new construction? The electrician said that heavy grinder use will kill GFCIs. He's had to come back in new construction that he just wired after large tile jobs where grinders were plugged in the sockets, kills the GFCI. All anecdotal info but something to consider. The outlets I think Im looking for are the hospital grade ones.
As I understand this graph, it indicates that the longer your circuit is overload, the pickier the GFCI gets. (two hours would be 720 seconds) http://apps.geindustrial.com/publibrary/checkout/GES-9883?TNR=Time%20Current%20Curves%7CGES-9883%7CPDF&filename=GES-9883.pdf
No, the chart says the more overloaded the circuit is, the faster the over-current protection will trip. The GFCI works on an entirely different principle than the over-current protection. What a GFCI does is measure the total current in and out of the hot and neutral wires. It should always be zero because all the current going one way is cancelled by all of it coming back the other way. If the sum is not zero that means current is leaking to ground somewhere and that means someone might be getting shocked. In such an event, it trips as fast as possible (milliseconds) at a very low leakage current (milliamps). It takes less than 100mA (0.1A) across your heart to send you into fibrillation, and a GFCI is designed specifically to prevent that from happening so it has to be both very sensitive and very fast.
720 seconds is 12 minutes. The overcurrent chart doesn't go above 1000 seconds, or a bit under 17 minutes, for the narrowest overcurrent conditions. The inset ground fault chart goes to 10,000 milliseconds, a.k.a. 10 seconds.
Its been a while since I've looked at code books, but I thought GFCIs should only be installed at the upstream receptacle of a string circuit. Something to do with multiple GFCIs on one circuit tend to cause problems with false trips. A GFCI breaker, plus GFCI receptacles at each outlet seems a bit redundant
My feelings also. EVSE also has built in gfci. Possible that a self test of one of the gfci's during the pauses in charging is causing the other gfci to trip.
Thats what I thought too but the electrician didnt seem concerned about it. I'm also learning there are different sensitivities of GFCI's and I can check local codes to see if I can use the less sensitive ones.
Here is something to consider...you mentioned you had a 20A GFCI breaker 'in the box'. I am assuming you are talking about the main breaker panel in your home. Please verify. Sometimes multiple GFCIs on the same circuit will cause noise on the line. Your 20A may be sensitive enough to pick up this noise and trip while you are charging your car. You don't need those GFCI's in those bathrooms, so I would suggest spending $5 and replace them with standard outlets and see if this resolves your issue.
