In a message dated 11/19/2005 6:31:33 P.M. Eastern Standard Time,
baycock@direcway.com writes:
That thing tells nothing about HOW the thing works- it reads like it was
written by an Ad Flack, not a technical person. If you find a real
description, I would like to see it.
Bill-W4BSG
Bill, Indeed that piece told how the unit works. If you missed it, it said
that the arc fault breaker monitors the current on the line being drawn by
the circuit. If there are minute fluctuations of current ie: sparking or
arcing the breaker shuts down. In normal use of current the variations are
"smooth" if you will. In the case of arcing the variations are more rough,
the
breaker senses this and shuts down. This was explained in the link I sent you
to. It also went on to say that the "one time arc" of a light switch turning
on or a plug being plugged in with a load on it will not trip the breaker
because if is a "one time" occurrence. There needs to be more of the arcing
in
a shorter period of time to have it shut down. I suppose if you switched on
the light switch quick enough in a short time, it might trip, but I am not
sure if that "waveform" would be rough enough to shut it down. Since these
breakers are relatively new and the code does not require them yet in ALL
areas
of the US I have not had any experience with them yet. However, I have heard
from my other electrician friends that have, that they are a "nightmare".
Indeed many a house fires have started as a result of arcing of poor
connections at outlets and switches. Since it is not an over current
situation a
regular breaker will not catch this problem and a fire can result. MANY older
houses were wired with "back stab only" devices. In the case of the "back
stab only" outlet that one plugs a vacuum cleaner into everyday (some women
are
anal about this) eventually the connection loosens up and begins to arc,
hence, any other load that is also connected downstream or at the same outlet
will continue to arc the connection, heat is generated and the wire starts to
burn, if conditions are right a fire can start from the high temperatures the
arc has caused on the wire. Many old outlet boxes have dust in them and dust
can ignite quickly. Needless to say I DO NOT "back stab" any devices. When
getting electrical estimates you should specify "side wiring" or else the
"cheap" bid on the job will most likely be back stabbed. Fortunately however
newer devices will not accept #12 wire as a back stab. Its a start in the
right direction. 73 Louie W1QJ
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