"Michael A. Terrell" wrote in
m:

No, it isn't. You can get nuisance trips on refrigerators and
freezers. They have grounded cords and they don't need GFCI. I
haven't
seen a new copy of the NEC lately, but I was told it is against code in
the US to use a GFCI to power either.



So, you're saying it's ok if the motor windings are leaking to, or worse,
connected to the chassis of the fridge as long as it's grounded? That's
the only thing that makes the GFCI trip....about 10ma of something's
wrong.

Back in the 1980's, I submitted a Navy Beneficial Suggestion that GFCIs
be installed at all electronic benches in our calibration and test
equipment repair facilities after an apprentice technician nearly killed
herself pulling a TV-7 tube tester out of its case, inadvertently not
unplugging it. The TV-7 has a big rheostat right close to the case on
the bottom (sitting up) with exposed windings where the slidewire contact
is. She really got burned as she was also touching exposed, highly
grounded metal parts of her workbench (another benny sugg submission).
Months went by and Navy accepted my suggestion system wide, not just in
our shop, handing me a very nice check for both suggestions.

We had some equipment that tripped the GFCI every time, frustrating the
hell out of the bench techs who blamed me. 3 benches, themselves,
tripped out every time it was reset.

Leaking line filters in every case, and the Navy loves line filters, were
the problem. Once the leaking line filters were replaced, making the
equipment SAFE should the ground connection become open, the problem
disappeared. Equipment in the shipyard became safer to operate because
of it. Some metal cased test equipment no longer "bit" its user with low
AC voltages on its grounded case, something we never figured out. It
must have been miswired grounds in the ships crazy balanced 115VAC line
systems. GFCIs fixed it because they instantly detected faulty line
filters, transformers with windings touching the frames or miswired
equipment that had been used for years.

None of my GFCIs on any appliances trips, except during major
thunderstorms. If they do trip, there's a reason....leaky appliances.
One hot water tank ago, there was a heater coil shorted to its metal
calrod sleeve quite near the balance point of the 240VAC line. This
ground fault only shorted out around 12% of the element's resistor so the
element just ran hot in one place, but cold in another from the
imbalanced load shooting high current through the little ground wire.
The GFCI found this short as soon as it happened, eliminating a potential
electrical fire hazard if the current had overrun the flimsy ground wire.

I think many electrical fires could be stopped if GFCI were required on
all circuits....including faulty appliances that trip them.