Arc-Fault nuisance tripping question

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Ballsdeep

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Recently we installed a dedicated circuit for a vehicle charging outlet (Tesla) at a client of ours. In order to make room for the 2 pole breaker we had to twin up some breakers. Two of these that we had to twin were arc-fault breakers. I know it's frowned upon but they were only controlling lighting circuits and it was the only way to make room. There were a total of five arc fault, now three that we twined up two. The remaining three are now intermittently tripping. How would the removal of one arc-fault breaker cause another to trip intermittently? Has anyone come across this before?

Thank you
 
Twin-up= combine the two circuits onto one breaker?? Did you also connect both neutrals? It's also possible that now you have met the (usually) 8 amp threshold where the AFCI will begin to detect a problem- or nuisance trip .

-Hal
 
Ballsdeep said:
How would the removal of one arc-fault breaker cause another to trip intermittently? Has anyone come across this before?
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Welcome to the Forum.

The erratic behavior of the remaining AFCIs (assuming they, and their branch circuits, were untouched, not relocated, left as found, and that each is a single pole AFCI) is quite unusual.

Given that you have an existing installation (the Premises Wiring System) and the erratic behavior started after your work, based upon what you've just described, I think a whole lot more information is needed.

Are the AFCIs branch feeder, combination, or a mixture of both? Who is the maker of these AFCIs?
What are the loads that are running on the erratic AFCI branch circuits when they trip?
How old is the structure, and what are the wiring methods involved? (raceway, cable, knob & tube)
Can you post a picture of the panel, before and after?
Was there really no AFCI nuisance tripping BEFORE you did your work?

You may well have to set a subpanel to get breaker pole space, for some of the non-AFCI breakers to be moved to, so you can restore the original AFCI protection, as well as have pole space for the charger. Having removed AFCI exposes you to liability. . .
 
The erratic behavior of the remaining AFCIs (assuming they, and their branch circuits, were untouched, not relocated, left as found, and that each is a single pole AFCI) is quite unusual.
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I understood the OP to say that the breakers with the additional circuits were tripping. If the existing untouched breakers are now nuisance tripping nothing surprises me with AFCIs. I think the only way to keep your sanity is to remove a couple of regular breakers and use the space for new breakers to feed a sub panel. Then move those circuits over to it as well as your charger and put those AFCIs back the way they were.

Of course now that you touched it, you are going to get the blame every time an AFCI trips even if they say they never did so before. :rant:

-Hal
 
Maybe it’s the Tesla charger throwing some electrical noise on the whole panel that the arc faults do not like.

Just saying because we had a plasma flat screen tv at one of our jobs that caused unrelated arc faults to trip.
 
It's not unheard of for AFCIs to trip for no good reason. For example, there was a case of a certain AFCI that would trip in the presence of amateur radio transmissions.
 
Gene B said:
It's not unheard of for AFCIs to trip for no good reason. For example, there was a case of a certain AFCI that would trip in the presence of amateur radio transmissions.
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If that wasn't happening before he "twinned up" why would it happen now ? I'm going out on a limb here but I'm assuming that "twinned up" means that the OP removed the AFCI breakers and installed tandem breakers to free up space for the 2-P vehicle charging breaker. I would caution the OP that this is beyond "frowned upon". This could possibly be an outright Code violation if the AFCI's were installed as a requirement for some previous installation. On the other hand, if a HO replaced several breakers with these AFCI's because he thought it was a good idea or believed they made his house wiring safer then it might be OK to make the change. I would advise the HO in either case.
hbiss said:
I think the only way to keep your sanity is to remove a couple of regular breakers and use the space for new breakers to feed a sub panel. Then move those circuits over to it as well as your charger and put those AFCIs back the way they were.
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I think this is good advice.
hbiss said:
Of course now that you touched it, you are going to get the blame every time an AFCI trips even if they say they never did so before.
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Again, right on the $$$.
 
mopowr steve said:
because he also introduced a new load (the charger) that could be the cause
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You may be correct but I have no experimental evidence or documentation to take issue with you on this. However, if this were a brand new install with a new load center and all new breakers couldn't the same be said if a car charger were part of the electrical load in the same panel ? That would mean that you couldn't have AFCI's in the same panel as a car charger circuit.

BTW, to prove that radio frequency does trip these breakers I tried an experiment at a high-rise condo in Jersey City, NJ. While inside an electric closet I had one of the security guard's walkie-talkie radios and just keyed the mic and tripped about 12 GFCI breakers all at once in the panel. The security team had been complaining that these breakers (for de-icing cable) were all off every morning they came in to do their shift. While they didn't specifically go into the electric closets, just talking on the radio while being in close proximity to the outlying circuits caused them to act like an antenna and thus tripped the breakers when they keyed up.
 
goldstar said:
You may be correct but I have no experimental evidence or documentation to take issue with you on this. However, if this were a brand new install with a new load center and all new breakers couldn't the same be said if a car charger were part of the electrical load in the same panel ? That would mean that you couldn't have AFCI's in the same panel as a car charger circuit.
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Sure, if you wanted to take the chance of the arc faults tripping. Which isn’t your problem but more so the manufacturers to remedy the issue between the charger and the breakers (which they had been doing with every revision of arc fault put out there). Which needs to be reported to the arc fault nuisance trip website so the breaker manufacturers can test these appliances against their product to determine where the correction needs to lie.
 
Thank you for all the responses. Sorry I was away for awhile.

It sounds like the Tesla charger may be causing the arc faults to trip. I'm almost positive though, that I have other clients with Teslas and arc faults who have not run into this. There was no room physically or cost-wise to install an entire new sub-panel just to make room for the 2 pole 50 for the charger.
 
Ballsdeep said:
Thank you for all the responses. Sorry I was away for awhile.

It sounds like the Tesla charger may be causing the arc faults to trip. I'm almost positive though, that I have other clients with Teslas and arc faults who have not run into this. There was no room physically or cost-wise to install an entire new sub-panel just to make room for the 2 pole 50 for the charger.
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You very well could have other clients with them. But every premis has its own unique technicalities due to length of wires, how wires are ran, spd’s, mov’s, bla,bla,bla and how that influences or quenches things.
 
Same Issue

Same Issue

We are having the same issue with a Tesla wall connector. We have installed 100's of these chargers, but this is a first. 2 year old house. Everything checks out, but when the car charges, random arcs trip in the panel. We have tried a different car and a different charger...so we know its something related to the home. Currently, I suspect the Eaton arc faults. But, I don't want to do a panel change for nothing....!
 
Ohmy said:
We are having the same issue with a Tesla wall connector. We have installed 100's of these chargers, but this is a first. 2 year old house. Everything checks out, but when the car charges, random arcs trip in the panel. We have tried a different car and a different charger...so we know its something related to the home. Currently, I suspect the Eaton arc faults. But, I don't want to do a panel change for nothing....!
Click to expand...

Call Eaton and see if they will give you the most current revised breakers in place of the ones that are installed.
 
Ballsdeep said:
The remaining three are now intermittently tripping.
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How intermittently? If it occurs frequently enough to assure repeatability, then I would open the breaker to the new car charger for a week or so and see if that eliminates the problem. If so, then you have strong evidence the car charger is causing the trips. If the AFCI's continue to trip with the car charger offline, then you know you have other issues.
 
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