In ,
DerbyDad03 typed:
On Feb 3, 8:39 pm, "Twayne" wrote:
,
DerbyDad03 typed:



On Feb 3, 4:13 pm, "Jay-T" wrote:
DerbyDad03 wrote:
On Feb 3, 3:29 pm, Mark wrote:
Use GFCI because it operates on the 'difference' in current
between live and neutral. If someone did get a contact or drop
the hair dryer in the wet metal bath tub any conseuent current
likely to trip the GFCI safely.-

-

agreed, but will the TEST button still work without a ground?

Mark

Yes.

The test button does not send any current to ground so no ground
is required for it to work.

Thanks. I wondered about that too.

Looks like I won't have a problem going ahead with the GFCI even
though there is no ground.- Hide quoted text -

- Show quoted text -

BTW...not only is it OK to (and you should) replace the ungrounded
bathroom receptacle with a GFCI, it is also code compliant to
replace any 2 prong, ungrounded receptacle with a 3 pronged
receptacle as long as that receptacle is protected by a GFCI and
marked as having No Equipment Ground.

For example, if you have a circuit full of daisy chained 2 pronged,
ungrounded receptacles, replace the first one in the circuit with a
GFCI and wire all the downstream 3 prong, yet still ungrounded
receptacles off of the load side.

It's a fairly common practice and allows for the use of three
pronged cords in "older" homes.

NO, it does NOT "allow" use of 3-wire equipment!! If a 3-wire piece
of equipment is plugged into an outlet, the earth ground in that
case DOES need to be present. THAT is why the outlets must be
labeled as having NO ground! It's to prevent just that kind of
accident waiting to happen.

HTH,

Twayne

--
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Perhaps we need some clarification here.

OK; since we're clarifying, lets be a tad more accuate. I only add this for
clarification, no other reason. Many homes have a mix of such 2 and 3 wire
installations and it's easy to misunderstand some things.


We are talking about people protection only. We're not discussing
whether the absence of a ground will be a detriment to the operation
of the equipment.

A GFCI is for "safety", not people. Kind of minor on the surface, but
important in the altogether. Also, lack of a ground for equipment that
needs it -could- lead to lethal shock situations where under a single fault
condition it could lead to anything from shock to fire.

It is my understanding that the GFCI will protect the user should
there be current leakage to ground within the device.

Well, not from "within the device" but from any point in the entire circuit
on the Load side of the GFCI; wire, connections, equipments, etc..
Sufficient leakage anywhere will trip the GFCI. It simply measures and
compares hot/neutral current, as you said.


If there is any type of short to ground within the device then there
will be a differential between the current on the hot and the current
on neutral and the GFCI will trip and the user will be protected.

If there is anything anywhere, not just within the device, that causes a
differential, the gfci will trip.

Why else would the NEC allow for the use of a 3 prong outlet on an
ungrounded circuit if they didn't expect you plug a 3 prong cord into
it?

NEC definitely recommends AGAINST doing so, and requires the markings. In
addition, NEC is not the final word; NEC is only minimum requirements. The
local Code Enforcement Office will have the final say on whether a 3-prong
outlet can be used without an earth ground connection. Here such 2-wire
methods with 3-wire outlets etc. are specifically verboten in the kitchen,
bathroom and outbuildings. Many people forget that it's the local codes that
must be satisfied; the NEC may be but one component of the electrical
requirements.
The NEC/local codes would reall only come into the picture if it was new
work. e.g. when I added a ckt, all they checked was the ckt, and nothing in
the rest of the house. Some localities however insist that if you touch the
wiring at all the whole building has to be brought up to code. It varies all
over the map.


You'll note that code says it must be labeled as No Equipment Ground,
not simply No Ground.

For the safety of us all, I won't mind if you correct me.

Nah, no serious corrections were needed. Just had time to do a little
further clarification, so did.

Regards,

Twayne`


--
Newsgroups are great places to get assistance.
But always verify important information with
other sources to be certain you have a clear
understanding of it and that it is accurate.