Bob Jansen
Member
I have to ask , I was told G.F.C.I.'s will work with out a ground but A.F.F.I.'s won't is this true ?
A.F.C.I's , G.F.C.I 's
- Thread starter Bob Jansen
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stickboy1375
Senior Member
- Location
- Litchfield, CT
Bob Jansen said:
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Cavie
Senior Member
- Location
- SW Florida
stickboy1375 said:
Hello?? Anybody home??
stickboy1375
Senior Member
- Location
- Litchfield, CT
Cavie said:
Nope... :grin:
JohnJ0906
Senior Member
- Location
- Baltimore, MD
Bob Jansen said:
I would say the EGC (equipment grounding conductor) isn't necessary for the AFCI to operate. I don't see a place for it to land on the breaker.... :grin:
EGC not necessary for GFCI to operate.
- Location
- Illinois
- Occupation
- retired electrician
Bob,
The AFCIs will work on circuits that do not have equipment grounding conductors, but is my opinion, they are much less effective when installed in circuits that do not have EGCs. I say this because most of the trips on an AFCI are from the ground fault protection circuit that is in all AFCIs. This works like a GFCI except that the trip point is set at about 30 mA. In many cases the fault or arc will cause a 30 mA ground fault long before the arc signature circuit part of the AFCI even starts looking at the fault. The currently available branch circuit and feeder type AFCIs start looking at the arc only when the fault current exceeds 75 amps, and the combination type that is required starting 1/1/08 starts looking with a 5 amp fault...both well above 30 mA. It is hard to have any type of arcing fault on a circuit that includes an EGC with out also having a ground fault.
Don
The AFCIs will work on circuits that do not have equipment grounding conductors, but is my opinion, they are much less effective when installed in circuits that do not have EGCs. I say this because most of the trips on an AFCI are from the ground fault protection circuit that is in all AFCIs. This works like a GFCI except that the trip point is set at about 30 mA. In many cases the fault or arc will cause a 30 mA ground fault long before the arc signature circuit part of the AFCI even starts looking at the fault. The currently available branch circuit and feeder type AFCIs start looking at the arc only when the fault current exceeds 75 amps, and the combination type that is required starting 1/1/08 starts looking with a 5 amp fault...both well above 30 mA. It is hard to have any type of arcing fault on a circuit that includes an EGC with out also having a ground fault.
Don
mdshunk
Senior Member
- Location
- Right here.
Curious to know what study you base that on?don_resqcapt19 said:
- Location
- Illinois
- Occupation
- retired electrician
Marc,
I have no study, but based on posts in this and other forums and conversations with AFCI manufacturers reps, it is my opinion. One rep said that his best estimate is that 95% or more of the trips are from the ground fault part of the breaker, and most of them are from wiring installation errors. Just think about what it would take to have a fault that is pulling 75 amps or more in a system with an EGC and not have a 30 mA ground fault.
Don
I have no study, but based on posts in this and other forums and conversations with AFCI manufacturers reps, it is my opinion. One rep said that his best estimate is that 95% or more of the trips are from the ground fault part of the breaker, and most of them are from wiring installation errors. Just think about what it would take to have a fault that is pulling 75 amps or more in a system with an EGC and not have a 30 mA ground fault.
Don
mdshunk
Senior Member
- Location
- Right here.
Oh, I quite aggree with that estimation, since that has been my experience in the field as well. I was just hoping you had some reading material to link to for me.don_resqcapt19 said:
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