"iwdplz" wrote in message
...
Because of the location of the landscape lights where it would be
difficult to install extra conduits underground, I suspect that this
junction box is the only neutral/ground source (not using a neutral from
some other part of the circuit). Probably the builder is using just the
ground and hot wire from this pool room switch box. If my understanding
of GFCI is correct, sounds like GFCI cannot be used for the landscape
lights because there would be no difference between neutral and ground in
this case and the GFCI neutral can never be a pure ground? I sometimes
get confused on this finer distinction because ground and neutral is
bonded together at the main panel.

The GFCI device senses the current going out on the hot leg and returning on
the neutral. If they are not equal, current is leaking to ground, and the
device cuts out. Where your landscape lights are concerned, the neutral wire
is probably broken, so to make the lights work, he just connected the bare
ground as a neutral replacement. That circuit won't work on a GFCI device as
there would always be leakage into ground on the bare wire, causing an
imbalance. It is also a potentially dangerous situation for anyone that may
touch one of these fixtures. If they happen to be touching anything that is
better grounded than the ground wire, they could become part of the circuit.