Arc Fault will not trip.

Status
Not open for further replies.

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Most afci breakers need to see at least 4 amps before it will trip. The test is not a good one however I am not sure it will trip anyway
 

sjsantucci

Member
Location
Connecticut
If the load is 14 amps and we are arcing between full load and no load, is it safe to say we are arcing over 4 amps?

Is is there a better way to test breaker?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Yeah I saw the 10 amps as 1.0 etc. Sorry. I had actually tried that experiment also and had no luck I am not sure what it would take to trip. I have heard members say that there is no way it will trip with 120V due to arcing.... IDK
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Simple, because the sensitivity had to be toned down on something that is already to primitive to be effective. The early versions were more likely to catch something like this, but also more likely to nuisance trip because a running vacuum motor looks identical to dangerous arcing. So what else can they do?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
One feature that will be very hard to reproduce will maintaining a *constant* current of more than 5A despite the arc. That is the combination that should trigger series arc detection, not an intermittent arc with a peak current above 5A.
And, as has been stated umpteen times already, you cannot sustain such an arc in air with only 120V AC to work with.
It might be easier, but a lot more dangerous, to get more than 75 A of parallel arc at home.
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
What else can they do?

Take up extra space in the loadcenters.
Add a bit of heating to the house.
Entertain electricians for a few moments while they count the blinks of the trouble light.
Give a false sense of security to those that believe that their house is now protected from electrical fires.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
One feature that will be very hard to reproduce will maintaining a *constant* current of more than 5A despite the arc. That is the combination that should trigger series arc detection, not an intermittent arc with a peak current above 5A.
And, as has been stated umpteen times already, you cannot sustain such an arc in air with only 120V AC to work with.


You can do it, but with dissimilar metals like carbon to bronze.


It might be easier, but a lot more dangerous, to get more than 75 A of parallel arc at home.


Which will trip a regular breaker :thumbsup:
 

kwired

Electron manager
Location
NE Nebraska
Is is there a better way to test breaker?
Manufacturers claim you must press the test button on the breaker;)

Wasn't that much over 4 amps?
At about 20 seconds into video they said the load was a hot box that draws about 15 amps.

They never had any sustained arc for any duration long enough to get the device into a trip condition. Such activity is difficult to accomplish without introducing more material to replace what has burned up/melted or otherwise displaced like a welder operator continues to feed the welding electrode into the work. Get some carbon involved in the path and you maybe can sustain an arc long enough to trip the AFCI. But how often do such conditions exist without intentionally being set up in a lab? I understand some tests done by manufacturers they even increased voltage just to get an arc to start:roll:
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I really doubt that you can move the wire fast enough to create the type of arc that the AFCI is designed to detect. It needs to see an arc fault signature for 4 half cycles out of 8 half cycles. I don't see a person being able to do that by moving a wire.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I really doubt that you can move the wire fast enough to create the type of arc that the AFCI is designed to detect. It needs to see an arc fault signature for 4 half cycles out of 8 half cycles. I don't see a person being able to do that by moving a wire.

But, that would mean a sustained arc, correct?
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
In the video below we took an arc fault breaker and simulated an arc at a receptacle. We were un able to get it to trip.


Was a new breaker. Tried it with another breaker in case first was faulty. Was a 14 amp load. Any ideas?

https://www.youtube.com/watch?v=-rfqqNg-uVE



Meet Bob H, an nfpa EE>>>>


https://www.youtube.com/watch?v=iLmC5quELrE


Afci technology will not mitigate a series arc of any caliber @ 120V

It will in the UL lab , utilizing a simulator , and zip cord wrapped in flammable tape @ 15KV

Anything else you hear is simply a LIE

~RJ~
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Meet Bob H, an nfpa EE>>>>


https://www.youtube.com/watch?v=iLmC5quELrE


Afci technology will not mitigate a series arc of any caliber @ 120V

It will in the UL lab , utilizing a simulator , and zip cord wrapped in flammable tape @ 15KV

Anything else you hear is simply a LIE

~RJ~


Experts could argue he is not doing it fast enough or holding a sustained arc... but the same could be said for UL's carbon to bronze series arc generator.
 

kwired

Electron manager
Location
NE Nebraska
Experts could argue he is not doing it fast enough or holding a sustained arc... but the same could be said for UL's carbon to bronze series arc generator.
And he isn't, but how common would it be for such conditions normally occur and why would we need to sense that condition?
 
Status
Not open for further replies.
Top