[Amps] 220V wiring: Was Question about safety ground connection

[Gudguyham@aol.com]

In a message dated 11/19/2005 6:31:33 P.M. Eastern Standard Time,  
baycock at 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