AFCO or GFCI tester valid?

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ELA

Senior Member
Occupation
Electrical Test Engineer
When it comes to the AFCI, how do we know just what it tests? I'm sure there are some out there that know more about these devices than many of us that install them, but for all we know they may just be operating a simple shunt trip type of device when you press the test button. They claim these devices recognize waveform characteristics associated with arcing conditions. Does pressing the test button introduce any of these conditions? If not how do we really know it will respond when called upon? GFCI test button actually does imbalance the current through the sensing coil, creating an actual condition that the device is designed to detect.

Here is what one band does:
http://forums.mikeholt.com/showthread.php?t=111163&highlight=afci+%2B+test

This indicator vs. tester debate with respect to AFCI's all a symatics/CYA game. There are AFCI testers that do a lot more than the internal test button does!
One problem and a big reason for the game they play is that the line impedance between the breaker and the Tester ( or actual fault) location can make all the difference as to whether or not the AFCI will trip.
 

kwired

Electron manager
Location
NE Nebraska
Here is what one band does:
http://forums.mikeholt.com/showthread.php?t=111163&highlight=afci+++test

This indicator vs. tester debate with respect to AFCI's all a symatics/CYA game. There are AFCI testers that do a lot more than the internal test button does!
One problem and a big reason for the game they play is that the line impedance between the breaker and the Tester ( or actual fault) location can make all the difference as to whether or not the AFCI will trip.
Note the bold part in the quote

Yes there is but the last I heard it didn't work when the circuit was over 75'

If that is true, will the AFCI provide its intended protection beyond 75' of circuit length?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
If that is true, will the AFCI provide its intended protection beyond 75' of circuit length?
I suppose it will I am just telling you from experience. A local EC went thru this when an inspector pulled out this $400 afci tester. It would work fine in the first two outlets of the circuit but not any further. Ideal admitted that it did not work well after 75 feet but the newer units were programmable and there was a software update that supposedly fixed the problem.
 

kwired

Electron manager
Location
NE Nebraska
I suppose it will I am just telling you from experience. A local EC went thru this when an inspector pulled out this $400 afci tester. It would work fine in the first two outlets of the circuit but not any further. Ideal admitted that it did not work well after 75 feet but the newer units were programmable and there was a software update that supposedly fixed the problem.

Again, a question of whether or not the AFCI does what the manufacturers claim it will do, and pushing these devices into code before they are done with development stage. Lots of R&D money was saved by making them code and effectively making the consumers part of the testing lab. That is exactly what they did when they developed the combination type AFCI, IMO, they should have never put the combination type wording into code, they should have been issuing product recall on the original design if people wanted to exchange the old ones for the improved "safer version". There are many other products out there that do same thing if there is a defect or design issue.

If you have a condition that the device is intended to respond to it should trip. If excess circuit length is going to have an effect, then at very least, maybe the device needs instructions indicating a maximum circuit length.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Again, a question of whether or not the AFCI does what the manufacturers claim it will do, and pushing these devices into code before they are done with development stage. Lots of R&D money was saved by making them code and effectively making the consumers part of the testing lab. That is exactly what they did when they developed the combination type AFCI, IMO, they should have never put the combination type wording into code, they should have been issuing product recall on the original design if people wanted to exchange the old ones for the improved "safer version". There are many other products out there that do same thing if there is a defect or design issue.

If you have a condition that the device is intended to respond to it should trip. If excess circuit length is going to have an effect, then at very least, maybe the device needs instructions indicating a maximum circuit length.

You respond as if i am responsible. I am just stating what I know. I didn't make the product nor do I own one.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
I know that everyone is going by this article http://www.mikeholt.com/mojonewsarc...I-Testers-versus-AFCI-Indicators~20050728.php. Tester- indicator I don't know

That's what I was getting at. From the 2012 UL White Book:
OUTLET CIRCUIT TESTERS (QCYU) GENERAL This category covers portable devices with fixed attachment plug blades, or probes attached to flexible leads, used to indicate various wiring condi-tions in 15 or 20 A branch circuits by a pattern of lights or other similar means along with markings or instructions to identify the probable wiring conditions which cannot be determined by the tester. The devices may include provisions for checking the functions of a ground-fault circuit interrupter (GFCI) connected to the branch circuit, or for indicating that a branch circuit is connected to an arc-fault circuit inter-rupter (AFCI). AFCI indicators operate by producing a waveform similar to an arc fault. Since these devices cannot produce an actual arc fault, an AFCI indi-cator may not trip every AFCI. AFCI indicators are provided with mark-ings or instructions that state the following or equivalent: ??CAUTION: AFCIs recognize characteristics unique to arcing, and AFCI indicators pro-duce characteristics that mimic some forms of arcing. Therefore the indica-tor may provide a false indication that the AFCI is not functioning prop-erly. If this occurs, recheck the operation of the AFCI using the test and reset buttons. The AFCI button test function will demonstrate proper operation.'' These devices are not intended for use as comprehensive diagnostic instruments.
 
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