WildT,
They work by electronically picking up the "arc signature" (voltage/current distortions). I think the "bedroom only" requirement comes from the unique nature of the "occupancy". i.e. for approx 16 hours a day the rooms are not occupied or "supervised", and when they are occupied the occupants are usually unconscious (I have a very boring life -- what a great set-up line though...). During the debate over requiring AFCI's, there were loads of stories about drapes, bedding, etc. hanging in front of receptacles, and catching on fire. Many electrical experts were sharply divided over whether they: worked as advertised; should be required; should be feed through device types vs breaker types, etc. My personal opinion is that they were shoved down the consumers throat by the insurance and manufacturing industries, who had everything to gain and nothing to lose. My personal rant on the subject can be read at the following thread:
http://www.mikeholt.com/forum/Forum1/HTML/005799.html (Len Bonosevich)
Some links to info:
http://www.ecmweb.com/ar/electric_basics_arcfault_protection/ http://www.zlan.com/arc.htm http://www.ul.com/auth/tca/fall02/Print/Print3.pdf http://www.ul.com/regulators/afci/AFCI_scenarios020502.pdf http://www.arcfault.org/index.htm Len
edit: spellin'
[This message has been edited by Len_B (edited 02-20-2003).]
