Glowing Connections & AFCIs

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Tomorrow night I'm covering AFCIs, GFCIs, and their cousins.

I just built a little mockup with a 2-space load center on a cord, a 15A AFCI inside the load center supplying a GFCI and a duplex receptacle on the load side of the GFCI. I mounted these on a board, and used LV cut-in rings for the devices. I left the ungrounded conductor hooked but not screwed down so that I can jiggle the black conductor on the duplex to simulate an arc fault.

I plugged in a little heater that draws 9.0A when running, and began arcing the connection. Once I got a little wild with my jiggling, the AFCI tripped. I reset the AFCI and then let it sit with a little arc on the screw. From Engel's report mentioned here I expected to be able to create a glowing connection to show the students with little difficulty, yet failed.

Has anyone been able to create a glowing connection, and if so, what should I try?

Edit to add: I had a sustained arc for twenty minutes or so before I got bored and put it away. Overall, I left it be for almost an hour or so.
 
Last edited:

PetrosA

Senior Member
So with a sustained arc for twenty minutes the AFCI didn't trip? Isn't that a good illustration of the limitations?

I'm thinking maybe coating the wire with carbon (lamp black) might help create a glowing connection, but I'm not sure.
 

kwired

Electron manager
Location
NE Nebraska
Interesting, we normally try to prevent this from happening, we do see it happen or at least where it has happened somewhat frequently if we are in the servicing side of the trade, yet we have difficulty creating it if we want to see it.

I think the conditions necessary to create the glowing connection take some time to develop (at least when they naturally happen) and require no disruptions of anything or that development has been tampered with. Even the slightest wiggling of a conductor will change the conditions, maybe will accelerate, maybe will retard the development of a glowing connection.

Good luck, if you find something that works for you let us know what you did.
 

fmtjfw

Senior Member
Interesting, we normally try to prevent this from happening, we do see it happen or at least where it has happened somewhat frequently if we are in the servicing side of the trade, yet we have difficulty creating it if we want to see it.

I think the conditions necessary to create the glowing connection take some time to develop (at least when they naturally happen) and require no disruptions of anything or that development has been tampered with. Even the slightest wiggling of a conductor will change the conditions, maybe will accelerate, maybe will retard the development of a glowing connection.

Good luck, if you find something that works for you let us know what you did.
My wife has a surefire method, every time a bulb burns out in her bathroom fan the AFCI trips. Maybe you could tap a lit bulb with a hammer?
 

__dan

Senior Member
Tomorrow night I'm covering AFCIs, GFCIs, and their cousins.

I just built a little mockup with a 2-space load center on a cord, a 15A AFCI inside the load center supplying a GFCI and a duplex receptacle on the load side of the GFCI. I mounted these on a board, and used LV cut-in rings for the devices. I left the ungrounded conductor hooked but not screwed down so that I can jiggle the black conductor on the duplex to simulate an arc fault.

I plugged in a little heater that draws 9.0A when running, and began arcing the connection. Once I got a little wild with my jiggling, the AFCI tripped. I reset the AFCI and then let it sit with a little arc on the screw. From Engel's report mentioned here I expected to be able to create a glowing connection to show the students with little difficulty, yet failed.

Has anyone been able to create a glowing connection, and if so, what should I try?

Edit to add: I had a sustained arc for twenty minutes or so before I got bored and put it away. Overall, I left it be for almost an hour or so.
Try plugging in the pickle light and see what happens. Should be no trip of the GFI and if the AFCI does not trip for the smoking pickle ... would be total scam. Maybe try the AFCI first and if it trips, it works. Then swap over to a regular 1p 20A breaker, the GFI outlet, and light up the pickle lamp. Be sure to buy two, one to eat and one to toast.

http://www.youtube.com/watch?v=tMhXCG6k6oA&feature=related
 

cadpoint

Senior Member
Location
Durham, NC
Tighten up the connections. Put a staple or screw between some various combinations or between some
twisted circuits, or even a single circuit- isolated.

Sorry didn't read your link, I might be way off base.
 
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