> "GFCI's protect against a very different mechanism, namely leakage
current. GFCI's sample current in the phase (hot) and neutral conductor,
and open the circuit if they are out of balance by more than
6-10 mA, which means that current must be flowing on the Green wire, and
producing enough IR drop between the Green wire and other grounded objects
(like plumbing)."
A point of clarification: as K9YC correctly states, the GFCI is looking
only at a current imbalance between the hot and neutral conductors.
However, a GFCI does not require a ground lead or green wire on a tool or
appliance to function. For example, double-insulated hand tools typically
use no ground wire in the line cord. Yet, the GFCI still performs its
function if the double insulation layer of the tool case was to break down
and create a leakage condition to anything at ground potential.
Paul, W9AC
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|