ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Since main bonding jumpers short Neutral to EGC, what keeps GFCI's from tripping when an incandescent lamp is plugged in?
Arc fault breaker
- Thread starter Donaciano_gonzalez@yahoo.
- Start date
- Status
- Occupation
- Licensed Electrician
The main bonding jumper is ahead of the GFCI.
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
I thought the answer was resistance.
Enough N-EGC resistance over zero Ohms that won't trip a GFCI, but insufficient resistance to trip AFCI, which looks for higher Ohms.
ptonsparky
Tom
- Occupation
- EC - retired
I don't remember ever having a GFCI that did not trip N-EG.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
Go ahead and wire up a GFCI receptacle with 12-2/14-2. Now lay the bare ground against the neutral terminal. Report back to us.
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Not with body resistance between N-EG.
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Trips every time without some body resistance between bare ground & neutral terminal.
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Neutral-to-EGC resistance similar to galvanic skin response has tripped AFCI devices for years, but not Ground Fault devices.
Buck Perish reported this in 2009, and electricians who understand this can fix AFCI issues, while others wont.
Buck Perish reported this in 2009, and electricians who understand this can fix AFCI issues, while others wont.
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
I think this is a very misunderstood practical application for you. I think you should try on a bench and document each part. You should also see how much resistance it takes to trip it without a load it'd be nice to know for multiple brands of afci.
mtnelect
HVAC & Electrical Contractor
- Location
- Southern California
- Occupation
- Contractor, C10 & C20 - Semi Retired
This article is based on the NEC 1999, and newer codes might be different. In newer codes additional locations have been added. Family room, dining room, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, and hallways.
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
This is not a technical debate. It does not matter if periodically updated laboratory tests, with several device models, and detailed specifications could disclose an unpublished AFCI function that helps pass UL 1699, perhaps more reliably than algorithm matching.
This debate threatens to tell customers AFCI's work with existing wiring, and that NEC 110.12(B) compliance makes old wiring last forever.
This debate threatens business as usual for contractors that exploit ignorance to up-sell remodel wiring. No published bench testing will change such industry practice, which refuses to make existing wiring work with AFCI's. That fools errand will remain a rare and a less rewarded specialty.
Industrial, commercial electricians, and many residential panel flippers have never used AFCI's in existing buildings, and may never need to, if they can continue to replacement rather than maintain existing wiring.
- Occupation
- Licensed Electrician
Body resistance will stop any trip on a AFCI, GFCI, GFPE whether it's a neutral to ground fault or a hot to neutral fault unless you put enough load through someone.
There is no skin response mumbo jumbo involved. AFCIs that have ground fault sensing technology in them will trip on a neutral to ground fault and AFCIs that have no ground fault sensing in them will not.
It's ironic that AFCIs are not required to have ground fault sensing in them since that is their only legitimate safety value.
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Most people should be able to trip any AFCI, just like forum member Buck Parish did in 2009.
The referenced clinical study calls "skin response" a population range of skin-contact resistance, which matched my Milwaukee meter.
Load-side GFCI issues are one of several causes for electrical smoke & power failure that service electricians should recognize & repair, without unnecessary construction or rewire jobs.
Nothing taught me better how to look beyond GFCI issues, defuse outlet bombs, inspect for damage, reject hazardous equipment, communicate with tech support, or defend my findings, than getting existing wiring to work with AFCI's.
- Occupation
- Licensed Electrician
That's because all AFCIs had ground fault sensing in them at the time. Now some GE AFCIs and some Eaton breakers do not. GE even advertises their single pole breakers as compatible with MWBC wiring.
Changes nothing about breaker operation.
Agree.
That's because there was a lot of improperly shared neutrals, poorly wired circuits, and neutral to ground faults that never showed up as a problem until they were forced to work on a breaker that had ground fault sensing technology in it. AFCI had nothing to do with it, the same problems and solutions would have come about with GFPE breakers.
ptonsparky
Tom
- Occupation
- EC - retired
We frequently used AFCI on older wiring, including K&T, successfully. NBD. My guys were very good at being able to identify and fix issues. Our advantage was almost always T&M.
- Status