Louis
Thanks for the kindergarten lecture. What you told me and what was in
the link was WHAT happens, not HOW. You also included a lot of extra
stuff about "side" connections and "back stab", that do not help.
I know what wires are, and even the difference between #12 and #14, and
why copper is better than aluminum for house wire. I even have wired to
code, and passed inspection. What I don't know is what I asked- "how
does it work?" I mean what is measured?, what is compared?. A GFI
measures the difference in current in two wires, to see if some current
is going where it should not.
If this gadget can tell the difference between a normal contact arc and
an abnormal one, how does it tell?
Even though it was on a .gov site,the link was to a Flack sales job on
why we should use this thing.. I want something that relates to the laws
of physics. Things like rise rates, pulse shape, delays or count,
frequencies,etc.
Incidentally- what was in the link did NOT rule out action as a result
of RF at HF frequencies. In fact, I don't remember any reference to RF
at all- I need to recheck that.
Bill-W4BSG
Gudguyham@aol.com wrote:
> 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
--
Bill Aycock W4BSG
Woodville, Alabama
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