GFCI Questions
To the Editor:
Regarding "Safe Wiring With
GFCIs," by Rex Cauldwell (12/92):
The last paragraph under the heading
"Incorrect Wiring of GFCIs" states
that "the incorrect hookup would be
immediately apparent if the test
button doesn't trip the device."
Unfortunately, this is untrue. The
test button is valid only if the device
is wired correctly regarding load and
line. I first suspected this after testing
many GFCI receptacles with a plugin
tester and finding that if load and
line connections are reversed, the
GFCI will only trip for ground faults
downstream from the device, and not
at the device itself. The best advice
to your readers is not to rely on the
built-in test button for verifying
correct installation,