AFCI/ GFCI breakers Kitchen

[olly]

I see contractors using a combo AFCI / GFCI breaker for a small appliance branch circuit for the kitchen and still mounting a GFCI outlet. Is that code? Isnt the breaker enough? Why install the gfci outlet?

 

[LarryFine]

Yes. Yes. Ignorance.

 

[Fred B]

I actually had an inspector insist on one at the receptacle even though showed him had it at the panel.

 

[olly]

I actually had an inspector insist on one at the receptacle even though showed him had it at the panel.

Not sure why, when you use a GFI tester the breaker will trip first in my experience

 

[James L]

Probably using dual function breakers because it's becoming common for box stores to only stock those. Then a gfci device for convenience, since (at least in theory) a ground fault in a kitchen would be much more common than an arc fault.

Theoretically, the kitchen gfci would trip before the breaker if the ground fault is in a small appliance.

Not that I agree with the logic, but I've seen it.

If I wanted that type of convenience, I would order afci-only breakers

 

[Fred B]

Not sure why, when you use a GFI tester the breaker will trip first in my experience

He made a "convenience" argument in front of home owner. Wasn't my job or my customers I was just an employee at that time.

 

[kwired]

Probably using dual function breakers because it's becoming common for box stores to only stock those. Then a gfci device for convenience, since (at least in theory) a ground fault in a kitchen would be much more common than an arc fault.

Theoretically, the kitchen gfci would trip before the breaker if the ground fault is in a small appliance.

Not that I agree with the logic, but I've seen it.

If I wanted that type of convenience, I would order afci-only breakers

I disagree on the receptacle tripping before the breaker.

If the fault is low level fault say right around that 4-6 mA threshold it might be a crapshoot as to which one trips first, but I would put more money on the breaker as it is also going to see any capacitive line loss where the receptacle won't.

Otherwise if the fault is well over that 4-6 mA I'd bet both trip nearly every time.

 

[Rock86]

I disagree on the receptacle tripping before the breaker.

If the fault is low level fault say right around that 4-6 mA threshold it might be a crapshoot as to which one trips first, but I would put more money on the breaker as it is also going to see any capacitive line loss where the receptacle won't.

Otherwise if the fault is well over that 4-6 mA I'd bet both trip nearly every time.

When I was going through training, we had this discussion and our result was that an AFCI at the panel and GFCI on the receptacle. If a ground fault were to occur with a combo and GFCI receptacle, then the homeowner would need to reset both.

In my experience, I have seen too many issues with using GFCI/AFCI combo breakers for the kitchen.... too much nuisance tripping.

 

[kwired]

When I was going through training, we had this discussion and our result was that an AFCI at the panel and GFCI on the receptacle. If a ground fault were to occur with a combo and GFCI receptacle, then the homeowner would need to reset both.

In my experience, I have seen too many issues with using GFCI/AFCI combo breakers for the kitchen.... too much nuisance tripping.

I'd bet most the nuisance tripping is from the AFCI function, and that you would still have similar performance when it comes to circuit being down from AFCI breaker and GFCI receptacle combination. GFCI's just don't have as much nuisance trips as AFCI's. Occasionally you get something with inductive kickback issues or RF problems, but otherwise the load either has a ground fault or it does not. AFCI has too many possible reasons to trip.

 

[Rock86]

I'd bet most the nuisance tripping is from the AFCI function, and that you would still have similar performance when it comes to circuit being down from AFCI breaker and GFCI receptacle combination. GFCI's just don't have as much nuisance trips as AFCI's. Occasionally you get something with inductive kickback issues or RF problems, but otherwise the load either has a ground fault or it does not. AFCI has too many possible reasons to trip.

From some research, I found articles that stated the electronics within the combo breakers are sensitive. Good luck getting a manufacture to give any confirmation on that statement though.
After replacing the breaker and adding the GFCI receptacle the issues did not occur again.

 

[James L]

I disagree on the receptacle tripping before the breaker.

If the fault is low level fault say right around that 4-6 mA threshold it might be a crapshoot as to which one trips first, but I would put more money on the breaker as it is also going to see any capacitive line loss where the receptacle won't.

Otherwise if the fault is well over that 4-6 mA I'd bet both trip nearly every time.

I hear you. But some people think linear.
In other words, if you have a gfci receptacle closer to the appliance, it would trip first.

Again, not my logic, nor do I agree.
Just throwing out what I've seen.

I've seen multiple, even numerous times, where a gfci receptacle is connected to the load side of another gfci receptacle, and both are tripped from the same event.

I don't think it adds any convenience. If anything, it's inconvenient because somebody thought they fixed it with the first reset button but now they have to go find a second one (or breaker)

 

[retirede]

I hear you. But some people think linear.
In other words, if you have a gfci receptacle closer to the appliance, it would trip first.

Again, not my logic, nor do I agree.
Just throwing out what I've seen.

I've seen multiple, even numerous times, where a gfci receptacle is connected to the load side of another gfci receptacle, and both are tripped from the same event.

I don't think it adds any convenience. If anything, it's inconvenient because somebody thought they fixed it with the first reset button but now they have to go find a second one (or breaker)

They won’t think they fixed with the first reset button, because without power, it won’t do anything.
But yes, still inconvenient.

 

[James L]

They won’t think they fixed with the first reset button, because without power, it won’t do anything.
But yes, still inconvenient.

They'll think they fixed it when they see the button is right there.

Then when it won't reset, they'll take the receptacle out and find there's no power in the box.

Then they'll probably scratch their head....

To be continued...

 

[jmellc]

He made a "convenience" argument in front of home owner. Wasn't my job or my customers I was just an employee at that time.

Then watch both the device and breaker trip & it will be your fault. They may or may not recall inspector forcing it.

 

[kwired]

From some research, I found articles that stated the electronics within the combo breakers are sensitive. Good luck getting a manufacture to give any confirmation on that statement though.
After replacing the breaker and adding the GFCI receptacle the issues did not occur again.

I hear you. But some people think linear.
In other words, if you have a gfci receptacle closer to the appliance, it would trip first.

Again, not my logic, nor do I agree.
Just throwing out what I've seen.

I've seen multiple, even numerous times, where a gfci receptacle is connected to the load side of another gfci receptacle, and both are tripped from the same event.

I don't think it adds any convenience. If anything, it's inconvenient because somebody thought they fixed it with the first reset button but now they have to go find a second one (or breaker)

Unlike the thermal-magnetic function of circuit breakers that can have different trip curve even when dealing with same amperage rating, to meet listing Class A GFCI's must trip within ?? milliseconds after sensing 4-6 mA of fault current. This sort of makes majority of what you will find, that is reputable and properly listed/tested, likely to all trip anytime you have a fault of above 6 mA. Like I said earlier if you hanging that 4-6 mA range with the fault current you may have some that will trip before others.

Current is same everywhere in a series circuit so if you have them all in series they all see same current, other than like I also mentioned earlier that long enough circuit run may allow for the upstream device to see more leakage because of capacitance, but that still only gets it and not the downstream device in those rare cases when fault current is pretty low, 4-6 mA requirement makes them all pretty sensitive.