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AFCI Testers versus AFCI Indicators
July 28th, 2005


As I was reading a nationally recognized trade magazine the other day, I noticed an advertisement for an "AFCI Tester" being advertised by Ideal Industries. After looking at their website and reviewing some of the product specifications, I decided I would download one of the instruction manuals. The model that I looked at was the #61-165.

Included in the instructions was the following phrase:
"The SureTest® w/AFCI, #61-165, also tests arc fault circuit interrupter (AFCI) devices to ensure that AFCI breakers protecting the circuit have been installed correctly. This test disrupts the electrical supply if a functional AFCI is present".

Here is another phrase found in the manual:
"Plug in the SureTest and check for correct wiring of receptacle and all remotely connected receptacles on the branch circuit. Then, go to the panel and operate the test button on the AFCI installed in the circuit. The AFCI must trip. If it does not, do not use the circuit - consult an electrician. If the AFCI does trip, reset the AFCI…Then, press the AFCI button to activate the test. The TEST icon and lightning bolt symbol light brightly on the display to let the user know that the AFCI test is being performed. The AFCI device should trip causing the display to blank out with the loss of power. If the AFCI fails to trip, the SureTest® will not lose power and the display shows a dimly lit lightning bolt. This non-trip condition would suggest:

  1. A wiring problem with a totally operable AFCI, or
  2. Proper wiring with a faulty AFCI".

I was immediately reminded of an article written by Underwriter's Laboratories (UL) dated March 21, 2005 that addressed this issue. The article can be found at

To paraphrase the article, there is no such thing as an AFCI tester, other than the test button that is an integral part of the AFCI device itself. The reason for this is that an AFCI device is very complex, and recognizes the actual waveform of an arcing fault. While the advertised "AFCI Testers" do produce a waveform similar to that of an arc fault, they cannot produce an actual arc fault. Because of this, the "tester" may not trip the AFCI circuit breaker, despite the breaker having nothing wrong with it. For this reason, UL classifies these devices not as "testers", but as "indicators", which is much more accurate.

These devices are tested under the UL 1436 standard, and are required to have included in the instructions the following clause (or equivalent):

"CAUTION: AFCIs recognize characteristics unique to arcing, and AFCI indicators produce characteristics that mimic some forms of arcing. Because of this the indicator may give a false indication that the AFCI is not functioning properly. If this occurs, recheck the operation of the AFCI using the test and reset buttons. The AFCI button test function will demonstrate proper operation."

While these indicators may have some value for convenience to determine if the outlet in question is on an AFCI protected circuit, they are not to be substituted for the test button of the AFCI circuit breaker, and they are not an AFCI tester.

Ryan Jackson

Response by Ideal Industries

Mike, in response to Ryan's inquiry on whether our line of test tools are "testers" or "indicators", I would like the opportunity to provide a little bit of background. Arc fault protection has been a subject of controversy for the last few years. Adoption is growing at a cautious rate. Even though, arc fault protection was adopted into the Code in 2002, many states and local municipalities have been hesitant to implement this evolving technology. Concerns continue to arise on being able to detect "bad arcs" that lead to fires and discern them from "good arcs" produced normally by appliances. The objective evidence of good performance is no house fires from electrical arcing by detecting the bad arcs and no nuisance tripping of the AFCI devices by recognizing the good arcs. Each AFCI device manufacturer has their own ideas and technology on how to best accomplish these two tasks.

Because of the evolving technology, the different product designs on the market, and the significance of having good performance, IDEAL believes that an independent, consistent, objective test standard needs to be available in the field to ensure protection exists. Additionally, it's important to check the entire branch circuit installation for protection -- not just the AFCI device.

These AFCI protection concerns were heightened, during a period of a few months earlier this year, when some AFCI devices stopped recognizing the 100+ amp arcing signal of AFCI testers being used to inspect installations. This caused one AFCI device manufacturer to take a stand that AFCI testers are not needed. And, UL backed this posturing. Please refer to Square D's white paper entitled "AFCI Tester - not really". To see how this can happen, please note that UL has two standards in regards to AFCI: UL1699 for devices and UL1436 for outlet testers. And, there is a gray area where these two standards do not meet. The testing method in UL1699 for devices is certainly not able to be duplicated in the field for proper installation verification. UL1436 for testers has specific, repeatable parameters that UL Listed AFCI testers are required to produce to mimic a "bad arcing" signature that does allow field verification of installation and protection. It is important to note that AFCI testers actually pulse over 100 amps on the branch circuit! But, there are no requirements for the AFCI breakers that mandate detection of this "bad arcing" signature and safely trip. In fact, UL further weakens the stance of AFCI testers by referring to them as "indicators" and requiring specific language in the instructions included with AFCI testers that places more weight on the "test button" on the AFCI device over the "test button" on the tester. So, if the tester does not trip the AFCI device but the device's own test button does trip itself, then the device is ok.

As the leader in branch circuit testing, IDEAL has a few concerns with this testing methodology. First, the "test button" on the AFCI device does not have the ability to check the entire branch circuit for proper installation and protection. An AFCI tester does give Installers, Service personnel, and Inspectors the ability to test a branch circuit for proper wiring and that each device on the circuit is properly protected. Second, each AFCI device manufacturer has its own "test button" and test routine on the device; hence, no testing consistency is present across manufacturers. Third, arc fault protection is an evolving technology with significant changes still ahead. AFCI devices currently on the market detect parallel arcing faults. By 2008, the NEC is to require Combination devices that detect parallel and series arcing faults. So, an independent field verification through an established, objective test standard that device manufacturers must comply with is important to assure consistency in arcing protection across manufacturers and installations.

IDEAL has offered to work with UL and the AFCI device manufacturers to remove the gray area between the AFCI device standard and the AFCI tester standard. But now, there is actually a growing movement to remove all AFCI testing parameters from UL1436, which would remove any ability for Installers and Inspectors to verify that a home's bedrooms are sufficiently protected from parallel arcing faults. So, the controversy will continue until these issues are acknowledged and resolved.

IDEAL firmly agrees with the Inspection community that they need the proper tools and methods to conduct their third party testing and to verify installations are to Code. And, we strongly feel that our SureTest® line of branch circuit testers (not indicators) meets those needs. In fact, the SureTest® 165 is the only test tool that looks behind walls to verify protection from both types of fire hazards: arcing faults and high resistance points.

I'd be happy to further discuss these issues along with a thorough review of our product offering to remove any doubt on whether our test tools are "testers" or "indicators".


Jim Gregorec
Group Manager - T&M Division
Ph: 815 895-1233
Fax: 815 899-7712

Ryan's Response

So, I guess in closing the answer as to whether or not an AFCI indicator is something worth buying is still in the eye of the beholder. When I first wrote this letter of concern to Ideal, it was with anger in my heart, as I viewed their marketing scheme as a way of pulling the wool over the eyes of the consumer. As always, however, it is interesting to hear multiple sides of the story.

Ryan Jackson
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01a. Understanding the NEC, Volume 1 Articles 90-460
Compliance with the National Electrical Code is a major concern for today’s engineers, designers and electricians. On the one hand, you need to keep job costs down. On the other hand, your electrical projects must meet code. And if you are an electrical inspector, you’ve got to ensure compliance with the code in a way that is fair, accurate, equitable, and consistent.

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Product Code: 05UND1
ISBN: 1-932685-16-2
Pages: 498
Illustrations: Over 900

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