IAEI Business Meeting
March 19, 2002
16 members attended
David E. Shapiro, Secretary/Treasurer
The business meeting of the George Washington Chapter was held on March 19, 2002. We had sixteen members, aside from our presenter: ten inspector members, two nonmembers, one lapsed, and three associate members. Wayne Robinson was absent, so Mike Raffael chaired.
The treasurers report and education coordinators report were included in the meeting notice.
General Meeting. Secretary/Treasurer David Shapiro brought up the question of whether there would be an advantage to seeking a domain name and using a forwarding service, so that people looking for the chapters web page would have less to type in, and a more-intuitive address. He reported that this would cost the chapter $18 a year, noting that the chapter would be riding the tiger, albeit not a voracious one; it would be awkward to stop using a forwarding service. There was minimal discussion, but the consensus seemed to be that simpler access would be worth the cost.
Larry Griffith, of the Central Pennsylvania Chapter, encouraged members of the George Washington Chapter to attend the Eastern Section meeting, which his chapter is hosting. This meeting is the closest it has ever been, and it will take place during the first full week of October 2002.
Program. The chapter was anticipating a less-than-sanguine perspective on the protection provided by circuit breaker arc-fault circuit interrupters (AFCIs) supporting a live demonstration. The chapter received far more than it expected, however. The presenter was consultant Bernard Schwartz, P.E., a fire protection engineer formerly of the United States Consumer Product Safety Commission (CCPSC). He was ably assisted, and opposed, by Clive W. Kimblin, Cutler-Hammers manager for applications and standards. It was not a catfight, but it certainly was lively.
Schwartz raised the following main points. AFCIs interrupt parallel arcing faults, and do so much more quickly than would normal circuit breakers operating in their instantaneous range. Bring a hot and a return conductor together and there will be a BANG! from the arc as current flowing through the gap trips a standard circuit breaker. Bring the same two wires together and there will be a mere pop from the arc as current flowing through trips an AFCI breaker. Unfortunately, there is no predicting how much life and property protection they can provide, even though they work exactly as they are designed to work. Many people, including many people attending this meeting, presumed that they are designed to interrupt all sorts of arcing and even glowing faults, and do so right quickly. Not so. They are designed to interrupt parallel arcing faults that reach and sustain a flow of 75 amperes. Glowing faults and series arcing faults may last indefinitely without tripping an AFCI, as Schwartz demonstrated, even while sparking repeatedly, and even when sustaining sufficiently high current flow to ignite nonmetallic conduit.
Many of those who are unhappy with the AFCI requirement, in the meeting and out, are concerned about this fact. Montgomery College Instructor Cleveland Tyler worried that homeowners might be outraged to have been misled, by the devices name, into thinking they are receiving more protection than AFCIs provide. Larry Griffith, who teaches code classes nationwide, was concerned that those of his students who dont study the Code and product standards carefully can end up with the same false idea. He is going to start making the distinction very explicit. Contractor and Electric League Officer Buddy Friedeman was relieved when Kimblin assured him that AFCIs will interrupt faults at aluminum terminations. Buddy estimated that 75 percent of aluminum conductor terminations at refrigerators are dangerously defective, especially when nonmetallic boxes have been used. He has measured more than 200ºF at these outlets. David challenged Kimblin on this assertion, confirming that AFCIs will interrupt these arcs only after they melt or burn enough to cause ground faults. People appeared less reassured.
So, AFCIs only interrupt a certain subset of arcing faults. Why the, did the U.S. Consumer Product Safety Commission encourage the development of this technology, and its adoption into the NEC? Woefully incomplete information seems to be responsible. Whenever a fire truck is dispatched to a fire, Schwartz told us, upon its return the driver has to check off the cause of the fire it attended on a run sheet. Among the causes from which this fire officer, who is not trained as an investigator, must choose, there are ten electrical options: one is an overheating electric-discharge ballast; the other nine are all phrased in terms of arcing. This is the basis for the national data reports attributing nearly nine percent of home fires to arcs, and this is why arcs are the problem that was proposed for solution.
How about capturing data on the real causes? Theres no money. In Montgomery County, Maryland, for instance, a fire investigator goes out only if a fire causes $10,000 worth of damage or loss of life. Other jurisdictions have similar restrictions, due to resource limitations. Therefore, using actual fire investigators data would bias results in some unknowable direction.
Schwartz concludes that there is no good data to indicate whether a significant proportion of fires would be prevented, because they can be attributed to the arcing faults that AFCIs are designed to interrupt. Therefore, their worth falls, in his view, to a judgment call based on personal experience and opinion. He strongly suspects, based on his decades of fire investigation, that the vast majority of electric fires are the result of the heating caused by a lower level of current flow, through resistance; not the result of high-current parallel arcs. Fire in the permanent wiring occurs, in his experience, due to overheating at the termination points. He believes that it is extraordinarily rare for a staple to be driven through NM-B cable hard enough, and at just the right angle, to cause a parallel arc from the hot to the return conductor. AFCIs are not designed to interrupt overheating, and he suspects that AFCIs will not help much to prevent such fires through indirect means. Therefore, while not questioning the ability of AFCIs to do their job, he questions the degree to which they are worth the investment. He believes the manufacturers that urged that AFCIs be required do not spend enough time talking about their limitations.
Here is where Kimblin differs. A couple of Code cycles ago, representatives of the Electronics Industry Association and the CPSC urged that the instantaneous-trip settings of circuit breakers be lowered, to interrupt large faults more quickly. Manufacturers fought this so as to avoid nuisance tripping. AFCIs, he believes, provide a superior solution.
He focused on the fact that as much as a billion dollars of property damage annually is attributed to electrical fires, nearly 400 deaths, and many more injuries. However much (or, one is polite enough not to say, little) of these costs could be reduced by utilizing AFCIs, he believes, doing so will be well worthwhile. They interrupt sputtering faults, both hot to grounded conductor and, he asserts, hot to grounding means, that would never trip time-delay circuit breakers, and other low-level AC arcs, tend to self-extinguish at the zero-crossing point, making them highly unlikely to start fires. Furthermore, he emphasized the fact that the AFCIs presently on the market, or planned for marketing, incorporate 30 mA ground-fault circuit interrupters. He talked repeatedly of AFCIs as protecting against other than parallel faults. His logic is that if a series or glowing fault does not burn through enough insulation to become a high-current parallel fault, in modern wiring it will burn through enough insulation even, he asserts, at receptacle terminations for 30 mA to flow to ground.
P.S. The State of Wisconsin has
not included the arc fault protection requirement when the 2002
NEC goes into affect January 1, 2003. The feeling is that AFCI
receptacles do not meet the requirement that the protection
device must protect the whole circuit including the feeder from
the panel to the AFCI receptacle in the bedroom and also if the
entire bedroom circuit must be protected that would also include
the required hard wired smoke detectors in the bedrooms and the
lighting outlets in the bedroom. If the AFCI device trips it
would also knock out the smoke detectors and lighting outlets in
the bedrooms creating more problems in alerting and safely
getting people out of the home in the event of a fire.
Rich Neuser, Electrical Inspector
Mike Holt's Comment: If you have any comments or feedback, please let me know, Mike@MikeHolt.com
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