Arc Fault Protection

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BAHTAH

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Does anyone know if there is any effort to get an exception in the code from the ARCH FAULT protection requirement where electronic ignitors are installed on built-in fireplaces installed in bedrooms?

Thanks, Grant
 
There have been proposals tendered to provide exceptions for many things, most noteably, life safety equipment and smoke detectors.

In the process leading up to the 2005 NEC, the CMP responsible for 210.12 was clear to state that their intent in the language of 210.12 was to include smokes, not except them.

The implication is, if a piece of equipment, while attempting to operate normally, causes an AFCI to trip, then the piece of equipment has the problem of poor design, and that the AFCI is OK.
 
At this point in the development of the NEC, it is going to take an overwhelming amount of substantiation to get an exception to section 210.12. Issues such as the inconvenience of nuisance tripping of the circuit from specialized equipment supplied by an afci protected circuit is simply not going to get any votes at this point. It is obvious that the CMP and the NFPA in general is only interested in going forward with afci implementation, so unless you have the research dollars, time, and expertise to override that of the afci technology manufacturers, it is not likely you will see any afci concessions anytime soon.
 
The arc-igniter on a fireplace should not trip an arc-fault breaker. Most of these igniter do not utilize electric power; they are piezo-electric (not sure of the spelling) and the motion of pushing the button generates the current for the spark. Those that are powered by electric do not use 120-volts, they operate at low voltage, so the transformer should prevent the arc-fault from detecting the igniter arc. If the arc-fault is tripping out, there is probably another reason.
 
Connecticut has provided an exception for smoke detectors in bedrooms so long as the feeder does not feed anything else in the room
 
I find it very upsetting that many local jurisdictions are second-guessing the NEC code-making panels and exempting Smoke Detectors from arc-fault protection. If arc-faults do not work, then let's get them removed from the NEC completely. If they DO work let's use them to PREVENT FIRES. These local jurisdictions are saying that it is more important to ANNOUNCE fires than it is to PREVENT fires. If I was a homeowner in one of these jurisdicitions, and my home was destroyed by a fire started in a smoke detector circuit, that may have been prevented by the installation of arc-fault protection, the AHJ would probably be sued.
 
I disagree. I believe the main intent of arc fault detectors is to protect mostly against an arc created from switches and plugs that are used frequently and may eventually fault, which is why there required in rooms where these devices are used frequently, either by plugging and unplugging, or on/off switching, including devices connected to the receptacles. Smoke detectors, once installed, are not moved around and have an extremely minute chance of malfunctioning on their own; in such a way as to cause arching in the detector itself.

I think this is why local jurisdictions omit these circuits from the afci requirement so long as their on a dedicated circuit. They should however require afci protection for other than just bedrooms, such as living rooms, dens, etc. I dont agree with the NEC omitting these circuits.
 
Ron,
I believe the main intent of arc fault detectors is to protect mostly against an arc created from switches and plugs that are used frequently and may eventually fault, which is why there required in rooms where these devices are used frequently, either by plugging and unplugging, or on/off switching, including devices connected to the receptacles.
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Sorry, but the AFCI device does not detect those types of arcs. They are designed to detect parallel arcing faults which are between the ungrounded and grounded conductors. They are not designed to detect switching arcs which are series in nature.
Don
 
hanskind,
If arc-faults do not work, then let's get them removed from the NEC completely. If they DO work let's use them to PREVENT FIRES.
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The problem is that the CMP and safety groups have been extensively lobbied by the AFCI manufactures to get their product into the code. There has been a lot of misleading information supplied in this effort to improve the bottom line of the manufacturers. There still is not an AFCI device on the market that can do what the manufacturers said AFCIs could do back in the original proposals to require these devices. Those proposals were for the 1996 code....some 13 years ago!!
Don
 
Sorry, i didnt state my opinion correctly.

Yes its true that afci detect faults between the line and ground. The reason to install them is to protect from faults that could occur in devices connected to plugs, such as lamps and vaccums, hair dryers etc, since faults could occur in the cords and switches of these devices over time. Cats chewing a cord, pinching, cheap equipment; that sort of thing. Im sure we have all seen cords with electrical tape around them or a knick from a pinch in a door!
 
The present AFCI do not protect against arc-faults in cord connected equipment, that is why there is a "Combination Type" AFCI that will be required effective January 1, 2008. I do not want to argue the merits of our present generation of AFCI's, but I do take issue with electrical officials, usually with no electrical background, deciding which parts of the code should be enforced. I personally believe that smoke detectors should NEVER be installed on a dedicated circuit. But that is a personal opinion. I believe they should be on a circuit with an often used load such as the bedroom or hallway light, so that if the circuit trips, the owner will know and will hopefully take steps to correct it. The purpose of AFCI's is to prevent fires. Do they work? I don't really know, but they seem to be of some value. If they prevent fires then they should be installed on the bedroom smoke detector circuit.
When smoke detectors first came on the market, and before they were required, I worked near the safety officer at a major manufacturing plant. Since he lived safety every day he bought a pair of smoke detectors as soon as they were available and installed one on each floor of his home. One day the downstairs detector went off. He searched the downstairs to find the fire, but could find nothing. He then went upstairs to find that the upstairs detector was on fire! Stuff happens. The code making panel has made it clear that AFCI should be installed for smoke detectors in bedrooms. What happens in 2008 when all residential general use circuits will require AFCI?
 
The present AFCI do not protect against arc-faults in cord connected equipment, that is why there is a "Combination Type" AFCI that will be required effective January 1, 2008.
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As far as I know this device is not on the market at this time and I have my doubts that there will be a 'functional" combination device on the market by 1/1/08.
Don
 
Ron,
Cats chewing a cord, pinching, cheap equipment; that sort of thing. Im sure we have all seen cords with electrical tape around them or a knick from a pinch in a door!
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That would all be fine except that the currently available AFCIs provide almost no protection beyond the fixed wiring of the building.
Don
 
The purpose of AFCI's is to prevent fires.
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That is the stated purpose, but in my opinon the real purpose is only money. Look at the fire cause info used to support the need for AFCIs. 85% of the fires occured in dwelling units over 20 years old. The AFCI is not a failsafe device. Few homeowners will do the required monthy test. How likely is it that the AFCI device with all of its electronics will still be functional 20+ years from now? Look at the GFCI with less electronics...in areas with thunderstorms about 57% were not fuctional after 7 years.
If you look at all of the numbers for the current AFCI rule, you would find that if there was 100% compliance with the rule, in the first year you would prevent 14 fires....out of about 1.7 million new dwelling units.
Don
 
Ron,
So is the purpose of afcis just to protect against bad installations?
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That is not the purpose, but that is the functionality of the currently available AFCI. The manufactures told the CMP and public safety groups in the original proposals (for the 1996 code) that the device that they has at that time could provide protection beyond the outlet. At this point in time there is not a device on the market that does what was promised some 13 years ago. The combination AFCI device that is required to be used starting 1/1/08 is said to have that functionality...that remains to be seen. I have zero confidence in the statements that are made by the manufacturers of these devices because they have so distorted the facts over the years. A recent published statement by on of the manufacturers said that the public has no reason to know how these devices work!!
Don
 
Telaid said:
The reason to install them is to protect from faults that could occur in devices connected to plugs, such as lamps and vaccums, hair dryers etc, since faults could occur in the cords and switches of these devices over time. Cats chewing a cord, pinching, cheap equipment; that sort of thing.
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The existing Branch/Feeder AFCI requires two (2) arc signatures within 8 half cycles, each of which have to exceed a threshold of 55 to 70 amps (the threshold depends upon the AFCI manufacturer's particular solution/compromise to the GRAND IDEA of AFCI.)

That is a very high current level at the location of the zip cord or tinsel cord.

The AFCI sensing circuitry simply can't reliably see beyond the Premises Wiring (System) outlet in the generic single family dwelling hundreds of feet from the little single phase PoCo transformer, where the outlet is a long way down a #14 circuit.

The new 2008 Combination AFCI is to have a threshold of 5 amps.

But, at present, the cat is "protected" from ignition by the AFCI only if the cat is chewing on the wires inside the wall.
 
Telaid said:
So is the purpose of afcis just to protect against bad installations?
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don_resqcapt19 said:
that is the functionality of the currently available AFCI.
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Anecdotally, to date, all but one case of the AFCI trouble shoots that I've been called to do has been instigated by the AFCI tripping because a grounded conductor got up against the EGC somewhere along the circuit.

There is no arc.

The AFCI is tripping, in these cases, because the grounded circuit conductor integrity has been compromised by a ground fault. . .this behavior of the AFCI is indistinguishable from a GFCI only by threshold. . .the ground fault current will be more than the 5 milliamp of a class A GFCI.

In my opinion, the AFCI is a pretty expensive "wiring integrity enforcer."

The one trouble shoot exception was a two week old pre-recall Square D AFCI that simply locked out and died.
 
Al,
The GFP is the most important part of the protection provided by the AFCI. Most electrical faults are the result of some type of poor connection that creates heat. The only way an AFCI, of either the branch circuit/feeder or combination, type detects this type of fault is when the damage progresses to a parallel arcing fault or a ground fault. I would expect that in the case of newer wiring systems, the ground fault will come first. In older wiring systems, by the time that there is enough damage to cause a parallel arcing fault, the fire may have already started.
Don
 
Don,

It appears that Siemens has introduced a combination type AFCI breaker
HERE is a link to an article from Siemens. They sent me a letter in the mail touting this acheivment.

Again I will be interested to see how these devices will work.

Chris
 
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