Cutler-Hammer AFCI Advertisement

[bphgravity]

I picked up a Cutler-Hammer brochure today at a local supply house that is promoting their AFCI's. The brochure is titled, "Do The Right Thing! Install Fire-Guard AFCI's."

Inside, there is section that answers frequently asked questions about AFCI's. Two topics caught my attention and seemed a little misleading. Heres what it says.

High Resistance Series Faults - These faults generally occur at loose electrical connections. There is no increased current or arcing to detect. Today's branch/feeder AFCIs have been shown to mitigate these faults by responding to the resulting parallel arc or ground fault due to insulation failure caused by resistive heating.

Series Arc - These are the sparks that occur when one wire in a circuit is broken. The current flow is very low (limited to the current that the load is drawing), and the spark interrupts within a short time (typically less than 1/60th of a second) causing the current to stop flowing. Such sparks are highly unlikely to cause a fire, and actually occur every time a light is turned on at a switch. Series arcs happen hundreds of times in homes every day in switches and appliances.

It seems to me that they are really trying hard to play down series arcing and glowing connections.

 

[charlie]

Re: Cutler-Hammer AFCI Advertisement

. . . mitigate these faults by responding to the resulting parallel arc or ground fault due to insulation failure caused . . .

If you really read what they are saying, they are not promising to actually open the circuit right away but only after it gets to the point of a parallel arc or ground fault. Of course, the GFCI portion of the circuit takes care of the ground fault and most circuit breakers will take care of the parallel arc.

They also make the argument that "series arcs happen hundreds of times in homes every day in switches and appliances" so they are not important since they will interrupt themselves within 1/60th of a second . . . HMMM . . . how long is one cycle?

These guys are slick.

 

[iwire]

Re: Cutler-Hammer AFCI Advertisement

Originally posted by charlie:
These guys are slick.

Marketing people slick?

How about snakes?

[ June 25, 2005, 07:29 AM: Message edited by: iwire ]

 

[hurk27]

Re: Cutler-Hammer AFCI Advertisement

Has anyone read the article in the NEC Digest (June 2005 Edition)

They are still claiming that all (100%) of receptacle outlets in residential installations have the full 75 amps available to detect an arc this would only be true if the arc was a bolted fault (which in this case there would be no arc) .

I don't think they are applying that if the resistance of the arc @ 1.6 ohm's was applied the current at the AFCI breaker, the arc current will be much less and cause the AFCI breaker not to detect the arc?

My caculations can be checked in this thread:
AFCI testers (Ideal Shure Test)