[R-390] GFCI issues

[rbethman]

1)  I am well aware that the GFCI functions at the mA level of 
differential current.

REMEMBER: Their own built-in GFCIs DO NOT TRIP.

A THIRD HAIR DRYER WAS ALSO USED - IT DID NOT TRIP THE GFCI>

2)  Considering the overall construction quality of THIS house and the 
others built within the very same time period, There is no telling WHAT 
is wrong.

3) The dumb foundation is 8" wider in the middle than it is on the 
ends.  (Which are within a 1/4 " of each other.

It has been the family joke that this house was built by a West Virginia 
maried couple, brother and sister.

The pre-built rafter assemblies are even made of 2" X 3" boards.

So I am NOT surprised to now suddenly have some weird electrical issue!

Bob - N0DGN


On 3/19/2013 4:32 PM, Bill Hawkins wrote:
> Group,
>
> A GFCI detects the differential current flow between hot and neutral
> paths TO THE LOAD. A problem in the house wiring or distribution panel
> can not trip a GFCI because it is on the wrong side of the detector.
>
> Please read this Wikipedia link
> http://en.wikipedia.org/wiki/Residual-current_device
>
> The article explains how a wire GFCI with no ground connection can
> trip on a fault. When both the hot and the neutral pass through
> the same toroid core in the same direction, no magnetic field
> will be generated in the core if the currents are balanced, as
> they must be if there is no fault. Faults before the core can not
> be detected. The fault must be after the core.
>
> Since the thing trips on about a 0.01 amp difference out of about
> 10 amps, it is pretty sensitive. Toroids are supposed to be self-
> shielding, but a strong local field could be a problem.
>
> <SNIP>
>
> Hope this helps,
> Bill Hawkins
>