I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the
outlets with two-wire ones, but it appears that I can't even buy them
any more. Certainly the local HD doesn't have any.

So the question is whether there's a proper way to connect a three-wire
outlet to antiquated two-wire cable?

Your simplest option is to put a GFCI receptacle in every location. It may
not sound cheap but the alternative is replacing the 2 wire cable with 3
wire cable. Not really practical unless you are already doing a gut and
remodel.

There should be a sticker that comes with the GFCI to alert users that the
plug is not really grounded. It does provide protection as it will trip if
any current flows into the ground tab.



"Richard M. Utter" wrote in message
...
I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the
outlets with two-wire ones, but it appears that I can't even buy them any
more. Certainly the local HD doesn't have any.

So the question is whether there's a proper way to connect a three-wire
outlet to antiquated two-wire cable?

That is pretty reasonable advice with one exception: Where the
3-wire is actually needed, such as for computers, stereos, etc..

Further: You don't need a GFCI at every location: You only need
one per circuit, placed in the right location, meaning the
receptacle which physically connects to the fuse/breaker box.
Then that receptacle and all those beyond on the same circuit are
protected.
You can also buy ckt brkrs with gfci functionality, along with
arc suppression and detection. IMO that would be the most
desired from a new buyer perspective. Don't be too surprised if
the lack of a third wire hurts some prospects, though.
If you're in doubt about anything, it's easy to just call your
local code enforcement office to get details: Every locations
adds its own laws and rules to the mix.

Pop


"PipeDown" wrote in message
nk.net...
Your simplest option is to put a GFCI receptacle in every
location. It may not sound cheap but the alternative is
replacing the 2 wire cable with 3 wire cable. Not really
practical unless you are already doing a gut and remodel.

There should be a sticker that comes with the GFCI to alert
users that the plug is not really grounded. It does provide
protection as it will trip if any current flows into the ground
tab.



"Richard M. Utter" wrote in message
...
I'm preparing my mother's home for sale. It was built about
1953 and the wiring lacks the usual third ground conductor. To
make it possible to conveniently plug in stoves,
refrigerators, and power tools with three-wire cords, my
father simply replaced two-wire outlets with three-wire ones,
leaving their ground lugs disconnected.

At this point, every switch and outlet in the house is worn
out, paint-covered, or installed up-side-down, so I plan to
replace all of them. I started out intending to turn the clock
back and replace all the outlets with two-wire ones, but it
appears that I can't even buy them any more. Certainly the
local HD doesn't have any.

So the question is whether there's a proper way to connect a
three-wire outlet to antiquated two-wire cable?

Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle and
connect several receptacles downsteam, you will get some GFCI protection but
not from current into ground (the ground tab on those will still be open).
Only at the GFCI receptacle itself do you get virtual safety ground
protection.




"Pop" wrote in message
news:QP4ag.1079$rT5.116@trndny04...
That is pretty reasonable advice with one exception: Where the 3-wire is
actually needed, such as for computers, stereos, etc..

Further: You don't need a GFCI at every location: You only need one per
circuit, placed in the right location, meaning the receptacle which
physically connects to the fuse/breaker box. Then that receptacle and all
those beyond on the same circuit are protected.
You can also buy ckt brkrs with gfci functionality, along with arc
suppression and detection. IMO that would be the most desired from a new
buyer perspective. Don't be too surprised if the lack of a third wire
hurts some prospects, though.
If you're in doubt about anything, it's easy to just call your local
code enforcement office to get details: Every locations adds its own laws
and rules to the mix.

Pop


"PipeDown" wrote in message
nk.net...
Your simplest option is to put a GFCI receptacle in every location. It
may not sound cheap but the alternative is replacing the 2 wire cable
with 3 wire cable. Not really practical unless you are already doing a
gut and remodel.

There should be a sticker that comes with the GFCI to alert users that
the plug is not really grounded. It does provide protection as it will
trip if any current flows into the ground tab.



"Richard M. Utter" wrote in message
...
I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the
outlets with two-wire ones, but it appears that I can't even buy them
any more. Certainly the local HD doesn't have any.

So the question is whether there's a proper way to connect a three-wire
outlet to antiquated two-wire cable?

Richard M. Utter wrote:
I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the
outlets with two-wire ones, but it appears that I can't even buy them
any more. Certainly the local HD doesn't have any.

So the question is whether there's a proper way to connect a three-wire
outlet to antiquated two-wire cable?
make sure you check the back of the box. sometimes they ran a ground
wire and secured it to the back of the box. my house was built in 62 and
that is what they did.

On Mon, 15 May 2006 19:03:15 GMT, "Richard M. Utter"
wrote:

I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

This is illegal, and life threatening, so you might want to fix that
quickly.

Per the NEC you can find the first outlet, and wire that with a GFCI,
and have it feed the downstream outlets. So the first(the GFCI) and
the downstream receptacles are ground fault protected. Just be sure
the follow the rules, and mark each outlet with the normal "GFCI
protected" and "No Equipment Ground" stickers.

Side note, a local jurisidiction here in eastern Pa, will not allow
this. You either route a ground wire, or you use two prong outlets.
The idea is to not update the outlets, but to replace the wiring
method to include a equipment ground wire.

Check with your local codes, they usually are more stringent than the
NEC.


At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the
outlets with two-wire ones, but it appears that I can't even buy them
any more. Certainly the local HD doesn't have any.

I've seen them at our HD, but if I had to buy them in bulk, I would go
to an electrical suppy house.


So the question is whether there's a proper way to connect a three-wire
outlet to antiquated two-wire cable?


As mentioned above, follow the codes, especially the requirement that
only qualified personal will work on electrical systems.

later,

tom @ www.FreelancingProjects.com

I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

.. . .

Per the NEC you can find the first outlet, and wire that with a GFCI,
and have it feed the downstream outlets. So the first(the GFCI) and
the downstream receptacles are ground fault protected. Just be sure
the follow the rules, and mark each outlet with the normal "GFCI
protected" and "No Equipment Ground" stickers.
.. . .
At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the


I'm fairly sure that GFCI breakers have a limit to how many downstream
outlets you're supposed to be able to feed with them. (four, maybe?)
If I was going to live in the house, I'de replace all of them. Since
OP is preparing the house for sale, the cheapest option is probably
to replace the breaker(s). Anyone who cares is going to be unhappy
about the lack of ground-wire, using breakers instead of GFCIs isn't
going to make matters worse.

Another thing to check is whether you've got armored metal cable
that's grounded, in which case, pigtailing the receptical ground
to the box may be enough to satisfy the house "inspector"s little
LED tester. (Whether that's safe or code compliant in your area
is another question.) My second-floor circuts are like that.

PipeDown wrote:

Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle and
connect several receptacles downsteam, you will get some GFCI protection but
not from current into ground (the ground tab on those will still be open).
Only at the GFCI receptacle itself do you get virtual safety ground
protection.

I think I understand you. But just to be sure, are you saying that even
without a ground wire connected to it the first GFCI receptacle would
trip if an appliance plugged into it equipped with a three wire cord and
plug developed internal leakage between hot and ground (or on the
fancier GFCIs also between neutral and ground.), but that you don't get
that level of protection on the downstream ones?

I'd assume you wouldn't get that protection on the first receptical
either if there was no ground wire connected to it. I can't see where a
leakage current to ground would flow if there was no ground wire for it
to flow through.

If what you said assumed there WAS a ground wire to connect to the GFCI
receptical then I agree with your statement, but that's prolly not what
the OP has, unless he's lucky and the wall boxes are grounded, perhaps
via the bare ground wire used in some of the old BX cables.

snipped

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."

The ground fault device and anything plugged into any outlets connected to
the load side of it, will cause the GFCI to trip if any leak of current to
ground occurs, regardless if the outlets are grounded. The GFCI does not
need a ground connected to it to function


"Jeff Wisnia" wrote in message
...
PipeDown wrote:

Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle
and connect several receptacles downsteam, you will get some GFCI
protection but not from current into ground (the ground tab on those will
still be open). Only at the GFCI receptacle itself do you get virtual
safety ground protection.

I think I understand you. But just to be sure, are you saying that even
without a ground wire connected to it the first GFCI receptacle would trip
if an appliance plugged into it equipped with a three wire cord and plug
developed internal leakage between hot and ground (or on the fancier GFCIs
also between neutral and ground.), but that you don't get that level of
protection on the downstream ones?

I'd assume you wouldn't get that protection on the first receptical either
if there was no ground wire connected to it. I can't see where a leakage
current to ground would flow if there was no ground wire for it to flow
through.

If what you said assumed there WAS a ground wire to connect to the GFCI
receptical then I agree with your statement, but that's prolly not what
the OP has, unless he's lucky and the wall boxes are grounded, perhaps via
the bare ground wire used in some of the old BX cables.

snipped

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."

RBM wrote:

The ground fault device and anything plugged into any outlets connected to
the load side of it, will cause the GFCI to trip if any leak of current to
ground occurs, regardless if the outlets are grounded. The GFCI does not
need a ground connected to it to function

Of course, but that's NOT what I asked.

I was talking about (internal fault) leakage to the safety ground lead
(chassis) oF an appliance with a three wire cord and plug. And, that
faulty appliance is plugged into a GFCI outlet which does not have a
ground wire run to it. i.e. an outlet which would require the little
label stuck on it warning that there was no safety ground there.

Take a look at Sam Goldwasser's diagrams and explain please how the GFCI
can sense internal leakage to the safety ground lead of the appliance if
the ground pin hole in the outlet isn't connected to anything.

http://www.codecheck.com/gfci_principal.htm

Jeff




"Jeff Wisnia" wrote in message
...

PipeDown wrote:


Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle
and connect several receptacles downsteam, you will get some GFCI
protection but not from current into ground (the ground tab on those will
still be open). Only at the GFCI receptacle itself do you get virtual
safety ground protection.

I think I understand you. But just to be sure, are you saying that even
without a ground wire connected to it the first GFCI receptacle would trip
if an appliance plugged into it equipped with a three wire cord and plug
developed internal leakage between hot and ground (or on the fancier GFCIs
also between neutral and ground.), but that you don't get that level of
protection on the downstream ones?

I'd assume you wouldn't get that protection on the first receptical either
if there was no ground wire connected to it. I can't see where a leakage
current to ground would flow if there was no ground wire for it to flow
through.

If what you said assumed there WAS a ground wire to connect to the GFCI
receptical then I agree with your statement, but that's prolly not what
the OP has, unless he's lucky and the wall boxes are grounded, perhaps via
the bare ground wire used in some of the old BX cables.

snipped

Jeff


--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."

Have you checked to see if a ground wire is attached to the back of the
receptacle boxes? My house was built at the same time and I just added
a jumper wire to the existing ground and then to my new three pronged
receptacles. Fully grounded.

if its armored BX just add a pigtail between box and receptable ground
terminal while observing hot black side to brass screw cold white wire
to silver colored screw. please dont use those backstap receptables
they are cheap but junk quality

Jeff Wisnia wrote:
I was talking about (internal fault) leakage to the safety ground lead
(chassis) oF an appliance with a three wire cord and plug. And, that
faulty appliance is plugged into a GFCI outlet which does not have a
ground wire run to it. i.e. an outlet which would require the little
label stuck on it warning that there was no safety ground there.

Take a look at Sam Goldwasser's diagrams and explain please how the GFCI
can sense internal leakage to the safety ground lead of the appliance if
the ground pin hole in the outlet isn't connected to anything.

The GFCI will not immediately sense if there is a leak to chassis
ground in a faulty appliance. However, the instant a person touches the
live chassis and completes a path to ground, the GFCI will trip,
preventing injury. A live chassis by itself isn't dangerous - only when
someone touches the chassis and gets shocked is it a problem, and a
GFCI outlet will protect against this.

Like the other post said, you don't have an imbalance until something or
someone creates the bridge to ground. Then the device trips




"Jeff Wisnia" wrote in message
...
RBM wrote:

The ground fault device and anything plugged into any outlets connected
to the load side of it, will cause the GFCI to trip if any leak of
current to ground occurs, regardless if the outlets are grounded. The
GFCI does not need a ground connected to it to function

Of course, but that's NOT what I asked.

I was talking about (internal fault) leakage to the safety ground lead
(chassis) oF an appliance with a three wire cord and plug. And, that
faulty appliance is plugged into a GFCI outlet which does not have a
ground wire run to it. i.e. an outlet which would require the little label
stuck on it warning that there was no safety ground there.

Take a look at Sam Goldwasser's diagrams and explain please how the GFCI
can sense internal leakage to the safety ground lead of the appliance if
the ground pin hole in the outlet isn't connected to anything.

http://www.codecheck.com/gfci_principal.htm

Jeff




"Jeff Wisnia" wrote in message
...

PipeDown wrote:


Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle
and connect several receptacles downsteam, you will get some GFCI
protection but not from current into ground (the ground tab on those
will still be open). Only at the GFCI receptacle itself do you get
virtual safety ground protection.

I think I understand you. But just to be sure, are you saying that even
without a ground wire connected to it the first GFCI receptacle would
trip if an appliance plugged into it equipped with a three wire cord and
plug developed internal leakage between hot and ground (or on the fancier
GFCIs also between neutral and ground.), but that you don't get that
level of protection on the downstream ones?

I'd assume you wouldn't get that protection on the first receptical
either if there was no ground wire connected to it. I can't see where a
leakage current to ground would flow if there was no ground wire for it
to flow through.

If what you said assumed there WAS a ground wire to connect to the GFCI
receptical then I agree with your statement, but that's prolly not what
the OP has, unless he's lucky and the wall boxes are grounded, perhaps
via the bare ground wire used in some of the old BX cables.

snipped

Jeff


--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."

RBM wrote:

Like the other post said, you don't have an imbalance until something or
someone creates the bridge to ground. Then the device trips

For the last time I'll say that I agree completely with all that. I
checked into this thread when I questioned this statement by PipeDown,
when he said:

********************

Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle
and connect several receptacles downsteam, you will get some GFCI
protection but not from current into ground (the ground tab on those
will still be open). Only at the GFCI receptacle itself do you get
virtual safety ground protection.

********************

If by "safety ground protection" PipeDown meant that the GFCI would trip
on an internal ground fault in an appliance I didn't believe it would
unless there was a ground lead connected to it.

As Goldwasser says:

**********************************

GFCIs and safety ground:

Despite the fact that a Ground Fault Circuit Interrupter (GFCI) may be
installed in a 2 wire circuit, the GFCI does not create a safety ground.
In fact, shorting between the Hot and Ground holes in the GFCI outlet
will do absolutely nothing if the GFCI is not connected to a grounded
circuit (at least for the typical GFCI made by Leviton sold at hardware
stores and home centers). It will trip only if a fault occurs such that
current flows to a true ground. If the original circuit did not have a
safety ground, the third hole is not connected. What this means is that
an appliance with a 3 prong plug can develop a short between Hot and the
(supposedly) grounded case but the GFCI will not trip until someone
touches the case and an earth ground (e.g., water pipe, ground from some
other circuit, etc.) at the same time.

*********************************

I'll say no more on the subject.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."





"Jeff Wisnia" wrote in message
...

RBM wrote:


The ground fault device and anything plugged into any outlets connected
to the load side of it, will cause the GFCI to trip if any leak of
current to ground occurs, regardless if the outlets are grounded. The
GFCI does not need a ground connected to it to function

Of course, but that's NOT what I asked.

I was talking about (internal fault) leakage to the safety ground lead
(chassis) oF an appliance with a three wire cord and plug. And, that
faulty appliance is plugged into a GFCI outlet which does not have a
ground wire run to it. i.e. an outlet which would require the little label
stuck on it warning that there was no safety ground there.

Take a look at Sam Goldwasser's diagrams and explain please how the GFCI
can sense internal leakage to the safety ground lead of the appliance if
the ground pin hole in the outlet isn't connected to anything.

http://www.codecheck.com/gfci_principal.htm

Jeff




"Jeff Wisnia" wrote in message
...


PipeDown wrote:



Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle
and connect several receptacles downsteam, you will get some GFCI
protection but not from current into ground (the ground tab on those
will still be open). Only at the GFCI receptacle itself do you get
virtual safety ground protection.

I think I understand you. But just to be sure, are you saying that even
without a ground wire connected to it the first GFCI receptacle would
trip if an appliance plugged into it equipped with a three wire cord and
plug developed internal leakage between hot and ground (or on the fancier
GFCIs also between neutral and ground.), but that you don't get that
level of protection on the downstream ones?

I'd assume you wouldn't get that protection on the first receptical
either if there was no ground wire connected to it. I can't see where a
leakage current to ground would flow if there was no ground wire for it
to flow through.

If what you said assumed there WAS a ground wire to connect to the GFCI
receptical then I agree with your statement, but that's prolly not what
the OP has, unless he's lucky and the wall boxes are grounded, perhaps
via the bare ground wire used in some of the old BX cables.

snipped

Jeff


--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."

PipeDown wrote:
Your simplest option is to put a GFCI receptacle in every location. It may
not sound cheap but the alternative is replacing the 2 wire cable with 3
wire cable. Not really practical unless you are already doing a gut and
remodel.

There should be a sticker that comes with the GFCI to alert users that the
plug is not really grounded. It does provide protection as it will trip if
any current flows into the ground tab.

Hi,
Ground tab is floating(=no ground) but in certain cases, if a device
plugged in has a leakage current it'll trip when person using it touches
the device housing(ground) after taking a jolt which could cause an
injury. Not a good adviuce from the safety point of view.



"Richard M. Utter" wrote in message
...

I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the
outlets with two-wire ones, but it appears that I can't even buy them any
more. Certainly the local HD doesn't have any.

So the question is whether there's a proper way to connect a three-wire
outlet to antiquated two-wire cable?

According to Goedjn :

I'm fairly sure that GFCI breakers have a limit to how many downstream
outlets you're supposed to be able to feed with them. (four, maybe?)

I've not seen any that hint at such a thing in their instructions.
There's no reason I can think of where that would make any sort
of sense. They have to be rated for 20A passthru, otherwise,
you couldn't use them at all. The detection circuitry has no way
of knowing (or caring) about how many outlets are downstream of it.

If they somehow did have such a restriction, I suspect that
they'd fail UL/CSA approvals.

But who knows, perhaps some manufacturer does have that in their
instructions to try to trick you to buying more GFCIs than you need.

It _would_ make a certain amount of sense to limit the number of
outlets beyond each GFCI in order to minimize the number of outlets
going dead when one trips. That's a useability issue, not a safety
or operability one.

If I was going to live in the house, I'de replace all of them.

I'd test 'em, and if they tripped properly, leave 'em alone.

Another thing to check is whether you've got armored metal cable
that's grounded, in which case, pigtailing the receptical ground
to the box may be enough to satisfy the house "inspector"s little
LED tester. (Whether that's safe or code compliant in your area
is another question.) My second-floor circuts are like that.

While the NEC does permit cable sheath as a ground, the CEC
hasn't for a long time, and I wouldn't recommend relying on
it unless there was no other alternative. Old armor can
get remarkably high resistances...
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

I hear you Jeff, I was actually responding to his post through yours



"Jeff Wisnia" wrote in message
. ..
RBM wrote:

Like the other post said, you don't have an imbalance until something or
someone creates the bridge to ground. Then the device trips

For the last time I'll say that I agree completely with all that. I
checked into this thread when I questioned this statement by PipeDown,
when he said:

********************

Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle and
connect several receptacles downsteam, you will get some GFCI protection
but not from current into ground (the ground tab on those will still be
open). Only at the GFCI receptacle itself do you get virtual safety ground
protection.

********************

If by "safety ground protection" PipeDown meant that the GFCI would trip
on an internal ground fault in an appliance I didn't believe it would
unless there was a ground lead connected to it.

As Goldwasser says:

**********************************

GFCIs and safety ground:

Despite the fact that a Ground Fault Circuit Interrupter (GFCI) may be
installed in a 2 wire circuit, the GFCI does not create a safety ground.
In fact, shorting between the Hot and Ground holes in the GFCI outlet will
do absolutely nothing if the GFCI is not connected to a grounded circuit
(at least for the typical GFCI made by Leviton sold at hardware stores and
home centers). It will trip only if a fault occurs such that current flows
to a true ground. If the original circuit did not have a safety ground,
the third hole is not connected. What this means is that an appliance with
a 3 prong plug can develop a short between Hot and the (supposedly)
grounded case but the GFCI will not trip until someone touches the case
and an earth ground (e.g., water pipe, ground from some other circuit,
etc.) at the same time.

*********************************

I'll say no more on the subject.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."





"Jeff Wisnia" wrote in message
...

RBM wrote:


The ground fault device and anything plugged into any outlets connected
to the load side of it, will cause the GFCI to trip if any leak of
current to ground occurs, regardless if the outlets are grounded. The
GFCI does not need a ground connected to it to function

Of course, but that's NOT what I asked.

I was talking about (internal fault) leakage to the safety ground lead
(chassis) oF an appliance with a three wire cord and plug. And, that
faulty appliance is plugged into a GFCI outlet which does not have a
ground wire run to it. i.e. an outlet which would require the little
label stuck on it warning that there was no safety ground there.

Take a look at Sam Goldwasser's diagrams and explain please how the GFCI
can sense internal leakage to the safety ground lead of the appliance if
the ground pin hole in the outlet isn't connected to anything.

http://www.codecheck.com/gfci_principal.htm

Jeff




"Jeff Wisnia" wrote in message
.. .


PipeDown wrote:



Use of a single GFCI or a GFCI breaker does not solve the problem of
not having a ground wire in the first place. If you use a GFCI
receptacle and connect several receptacles downsteam, you will get
some GFCI protection but not from current into ground (the ground tab
on those will still be open). Only at the GFCI receptacle itself do
you get virtual safety ground protection.

I think I understand you. But just to be sure, are you saying that even
without a ground wire connected to it the first GFCI receptacle would
trip if an appliance plugged into it equipped with a three wire cord
and plug developed internal leakage between hot and ground (or on the
fancier GFCIs also between neutral and ground.), but that you don't get
that level of protection on the downstream ones?

I'd assume you wouldn't get that protection on the first receptical
either if there was no ground wire connected to it. I can't see where a
leakage current to ground would flow if there was no ground wire for it
to flow through.

If what you said assumed there WAS a ground wire to connect to the GFCI
receptical then I agree with your statement, but that's prolly not what
the OP has, unless he's lucky and the wall boxes are grounded, perhaps
via the bare ground wire used in some of the old BX cables.

snipped

Jeff


--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."

RBM (remove this) wrote:
The ground fault device and anything plugged into any outlets connected to
the load side of it, will cause the GFCI to trip if any leak of current to
ground occurs, regardless if the outlets are grounded. The GFCI does not
need a ground connected to it to function

Really? (Slaps head thinking of long hours spent snaking ground wires
from clamp on water pipe near meter to newly installed GFI outlets in
bathroom and kitchen of rented house with two wire ungrounded wiring.)



"Jeff Wisnia" wrote in message
...
PipeDown wrote:

Use of a single GFCI or a GFCI breaker does not solve the problem of not
having a ground wire in the first place. If you use a GFCI receptacle
and connect several receptacles downsteam, you will get some GFCI
protection but not from current into ground (the ground tab on those will
still be open). Only at the GFCI receptacle itself do you get virtual
safety ground protection.

I think I understand you. But just to be sure, are you saying that even
without a ground wire connected to it the first GFCI receptacle would trip
if an appliance plugged into it equipped with a three wire cord and plug
developed internal leakage between hot and ground (or on the fancier GFCIs
also between neutral and ground.), but that you don't get that level of
protection on the downstream ones?

I'd assume you wouldn't get that protection on the first receptical either
if there was no ground wire connected to it. I can't see where a leakage
current to ground would flow if there was no ground wire for it to flow
through.

If what you said assumed there WAS a ground wire to connect to the GFCI
receptical then I agree with your statement, but that's prolly not what
the OP has, unless he's lucky and the wall boxes are grounded, perhaps via
the bare ground wire used in some of the old BX cables.

snipped

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Life is like a sewer -- what you get out of it depends on what you put
into it."

On Mon, 15 May 2006 17:20:23 -0400, Goedjn wrote:


I'm preparing my mother's home for sale. It was built about 1953 and the
wiring lacks the usual third ground conductor. To make it possible to
conveniently plug in stoves, refrigerators, and power tools with
three-wire cords, my father simply replaced two-wire outlets with
three-wire ones, leaving their ground lugs disconnected.

. . .

Per the NEC you can find the first outlet, and wire that with a GFCI,
and have it feed the downstream outlets. So the first(the GFCI) and
the downstream receptacles are ground fault protected. Just be sure
the follow the rules, and mark each outlet with the normal "GFCI
protected" and "No Equipment Ground" stickers.
. . .
At this point, every switch and outlet in the house is worn out,
paint-covered, or installed up-side-down, so I plan to replace all of
them. I started out intending to turn the clock back and replace all the


I'm fairly sure that GFCI breakers have a limit to how many downstream
outlets you're supposed to be able to feed with them. (four, maybe?)
If I was going to live in the house, I'de replace all of them. Since
OP is preparing the house for sale, the cheapest option is probably
to replace the breaker(s). Anyone who cares is going to be unhappy
about the lack of ground-wire, using breakers instead of GFCIs isn't
going to make matters worse.

I believe, gotta look it up, if you don't use gfci receptalces, you
are stuck with using two prong receptalces.




Another thing to check is whether you've got armored metal cable
that's grounded, in which case, pigtailing the receptical ground
to the box may be enough to satisfy the house "inspector"s little
LED tester. (Whether that's safe or code compliant in your area
is another question.) My second-floor circuts are like that.




later,

tom @ www.MedJobSite.com

On Tue, 16 May 2006 05:01:00 -0000, (Chris
Lewis) wrote:

According to Goedjn :

I'm fairly sure that GFCI breakers have a limit to how many downstream
outlets you're supposed to be able to feed with them. (four, maybe?)

I've not seen any that hint at such a thing in their instructions.
There's no reason I can think of where that would make any sort
of sense. They have to be rated for 20A passthru, otherwise,
you couldn't use them at all. The detection circuitry has no way
of knowing (or caring) about how many outlets are downstream of it.

If they somehow did have such a restriction, I suspect that
they'd fail UL/CSA approvals.

But who knows, perhaps some manufacturer does have that in their
instructions to try to trick you to buying more GFCIs than you need.

It _would_ make a certain amount of sense to limit the number of
outlets beyond each GFCI in order to minimize the number of outlets
going dead when one trips. That's a useability issue, not a safety
or operability one.

If I was going to live in the house, I'de replace all of them.

I'd test 'em, and if they tripped properly, leave 'em alone.

Another thing to check is whether you've got armored metal cable
that's grounded, in which case, pigtailing the receptical ground
to the box may be enough to satisfy the house "inspector"s little
LED tester. (Whether that's safe or code compliant in your area
is another question.) My second-floor circuts are like that.

While the NEC does permit cable sheath as a ground, the CEC
hasn't for a long time, and I wouldn't recommend relying on
it unless there was no other alternative. Old armor can
get remarkably high resistances...

Very true abotu the high inductive resistance, why AC now comes with a
shorting wire. But if the AC is old, the wiring method should have
been per code when it was installed, so why not just pigtail the metal
boxes, if they exit.

Heck, I think the NEC allows for not pigtailes if you can establish a
ground off the yoke in contact with a grounded box. Not sure, since I
think the cost of ground screw and wire is cheap to ensure good ground
connection.

later,

tom @ www.Consolidated-Loans.info

On Tue, 16 May 2006 02:30:15 -0400, wrote:

On Tue, 16 May 2006 05:01:00 -0000, (Chris
Lewis) wrote:

While the NEC does permit cable sheath as a ground, the CEC
hasn't for a long time, and I wouldn't recommend relying on
it unless there was no other alternative. Old armor can
get remarkably high resistances...
It would still be plenty to trip the GFCI if you had a ground fault to
the case of attached equipment and eliminate one of the problems
mentioned here. Actually AC cable does pretty well if it was properly
installed. I did a survey of some old WWII buildings that were being
converted and all of the AC runs were 1 ohm under a test load (Ecos
tester)


Ohms is a measure of resistances, but typically measure using DC. The
old AC has inductive resistance, which is the problem. So I've been
told.

later,

tom @ www.MedJobSite.com

" wrote:

if its armored BX just add a pigtail between box and receptable ground
terminal while observing hot black side to brass screw cold white wire
to silver colored screw. please dont use those backstap receptables
they are cheap but junk quality

Also don't confuse the "pushwire" outlets which grab the inserted wire
with a crummy spring tab with the "backwire" outlets that clamp the wire
inserted in the hole when you tighten the screw. The "backwire" type are
just fine while the "pushwire" type are junk.

Pete C.

According to Tom The Great :
On Tue, 16 May 2006 02:30:15 -0400, wrote:

On Tue, 16 May 2006 05:01:00 -0000, (Chris
Lewis) wrote:

While the NEC does permit cable sheath as a ground, the CEC
hasn't for a long time, and I wouldn't recommend relying on
it unless there was no other alternative. Old armor can
get remarkably high resistances...
It would still be plenty to trip the GFCI if you had a ground fault to
the case of attached equipment and eliminate one of the problems
mentioned here. Actually AC cable does pretty well if it was properly
installed. I did a survey of some old WWII buildings that were being
converted and all of the AC runs were 1 ohm under a test load (Ecos
tester)


Ohms is a measure of resistances, but typically measure using DC. The
old AC has inductive resistance, which is the problem. So I've been
told.

About a year back when this issue was raised before, I ran the
numbers can came up with a value of a hundred microhenries of
inductance in 100' worth of AC. That can be ignored at 60hz.
Further, as much of the turns will have shorts to adjacent
banding, that will kill most of the inductance (even a single
winding-to-winding short in a coil makes a huge difference).

The sheath on AC has been made in a variety of ways over the
years. Aluminum, cut ribbons of galvanized steel, and other things.

Cut galv. ribbon has gaps in the coating - moisture = rustout.
Aluminum surface oxidation. Corrosion on connectors/boxes. Etc.

I can imagine that WWII military buildings were made with the good stuff,
and installed rather better than average.

I personally would hesitate to use AC armor as ground in
old systems where it was more of an incidental box-to-box ground
rather than something more actively involved in direct grounding
of devices via third wire grounding systems which didn't exist
at the time these circuits were laid.

My co-author of the electrical wiring faq has seen AC armor
participating in a dead short where it was a poor enough
connection to _not_ blow the breaker, but a good enough conductor
to glow red hot.

There was a major fire in a Los Vegas casino several years back
which turned out to be just this sort of thing.

Heck, another close friend found an AC armor segment to be fully
live, yet, as far as he could tell from the wire segments he
could see, was fully bonded back to the panel. Not.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

According to Tom The Great :

I believe, gotta look it up, if you don't use gfci receptalces, you
are stuck with using two prong receptalces.

The NEC does not permit 3 prong outlets on ground-less circuits
_unless_ they're downstream of a GFCI (and labeled as such).

The CEC used to permit you to plug the third prong with silicone
goop, but not for some time.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

On Wed, 17 May 2006 03:52:12 -0000, (Chris
Lewis) wrote:

According to Tom The Great :
On Tue, 16 May 2006 02:30:15 -0400, wrote:

On Tue, 16 May 2006 05:01:00 -0000, (Chris
Lewis) wrote:

While the NEC does permit cable sheath as a ground, the CEC
hasn't for a long time, and I wouldn't recommend relying on
it unless there was no other alternative. Old armor can
get remarkably high resistances...
It would still be plenty to trip the GFCI if you had a ground fault to
the case of attached equipment and eliminate one of the problems
mentioned here. Actually AC cable does pretty well if it was properly
installed. I did a survey of some old WWII buildings that were being
converted and all of the AC runs were 1 ohm under a test load (Ecos
tester)


Ohms is a measure of resistances, but typically measure using DC. The
old AC has inductive resistance, which is the problem. So I've been
told.

About a year back when this issue was raised before, I ran the
numbers can came up with a value of a hundred microhenries of
inductance in 100' worth of AC. That can be ignored at 60hz.
Further, as much of the turns will have shorts to adjacent
banding, that will kill most of the inductance (even a single
winding-to-winding short in a coil makes a huge difference).

The sheath on AC has been made in a variety of ways over the
years. Aluminum, cut ribbons of galvanized steel, and other things.

Cut galv. ribbon has gaps in the coating - moisture = rustout.
Aluminum surface oxidation. Corrosion on connectors/boxes. Etc.

I can imagine that WWII military buildings were made with the good stuff,
and installed rather better than average.

I personally would hesitate to use AC armor as ground in
old systems where it was more of an incidental box-to-box ground
rather than something more actively involved in direct grounding
of devices via third wire grounding systems which didn't exist
at the time these circuits were laid.

My co-author of the electrical wiring faq has seen AC armor
participating in a dead short where it was a poor enough
connection to _not_ blow the breaker, but a good enough conductor
to glow red hot.

There was a major fire in a Los Vegas casino several years back
which turned out to be just this sort of thing.

Heck, another close friend found an AC armor segment to be fully
live, yet, as far as he could tell from the wire segments he
could see, was fully bonded back to the panel. Not.


You have very very good points, but I'm thinking they reflect on the
older BX cable that didn't have the shorting wire. Infact AC is so
recognized as a good ground, if they toss in an insulated ground wire
you get HFAC. Sure there more qa done, but the jacket becomes the
normal ground fault, and the isolated ground is used for the third
prong for sensitive medical equipment.

Now I doubt this 1953 house has AC with the quality control of HFAC,
but just making a point that AC is good, damn good when properly used,
and installed.



later,

tom @ www.FreelancingProjects.com

On Wed, 17 May 2006 03:55:36 -0000, (Chris
Lewis) wrote:

According to Tom The Great :

I believe, gotta look it up, if you don't use gfci receptalces, you
are stuck with using two prong receptalces.

The NEC does not permit 3 prong outlets on ground-less circuits
_unless_ they're downstream of a GFCI (and labeled as such).

Yeah that is what I said, but I was wondering if you put in a GFCI
breaker, does that open you up for using 3 prong receptacles. Haven't
looked it up yet.

later,

tom @ www.CarFleaMarket.com




The CEC used to permit you to plug the third prong with silicone
goop, but not for some time.

According to Tom The Great :

You have very very good points, but I'm thinking they reflect on the
older BX cable that didn't have the shorting wire.

Frankly, I don't think the teensy little shorting wire is of
much use, if you have termination problems, for example,
the shorting wire won't help.

Besides, in a system old enough to have two prong outlets (as
per the OP's original posting), the cable is not going to have
the shorting wire anyway. It's going to be a highly tarnished,
pitted, gritty, dirty grey color, where the connections are
going to be highly doubtful and the banding may be fairly brittle.
Especially since it wasn't originally intended to be a ground path
for 3 wire devices.

Infact AC is so
recognized as a good ground, if they toss in an insulated ground wire
you get HFAC.

Heh. In Canada, AC armor is so NOT recognized as a good ground, that
you're not permitted to use it as a ground. Period. Here, AC armor
is only considered physical protection. The only armored cable
commonly available here for normal residential purposes is the stuff
called "MC" in the US - contains a full size bare ground wire.

[There are other armored cables of course, but not ones that you'd
use in a home except in exceptional conditions. Eg TECK cable -
suitable for power feeds in corrosive/high physical damage risk.
Eg: mines. Power feeds for portable carnival rides.]

Sure there more qa done, but the jacket becomes the
normal ground fault, and the isolated ground is used for the third
prong for sensitive medical equipment.

Now I doubt this 1953 house has AC with the quality control of HFAC,
but just making a point that AC is good, damn good when properly used,
and installed.

I suspect there's rather more to HVAC than simply a "well Q/A'd AC".
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

According to :
On Wed, 17 May 2006 17:51:05 -0400, Tom The Great
wrote:

Yeah that is what I said, but I was wondering if you put in a GFCI
breaker, does that open you up for using 3 prong receptacles.
Yes it does

If they're labeled.

The intent is to ensure that every three prong outlet is either
_really_ grounded, or, provides warning to the user that it's
GFCI'd.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

According to Chris Lewis :
Now I doubt this 1953 house has AC with the quality control of HFAC,
but just making a point that AC is good, damn good when properly used,
and installed.

I suspect there's rather more to HVAC than simply a "well Q/A'd AC".

phoo! HFAC. I couldn't find any specs for it online.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

On Thu, 18 May 2006 15:35:23 -0000, (Chris
Lewis) wrote:

According to Chris Lewis :
Now I doubt this 1953 house has AC with the quality control of HFAC,
but just making a point that AC is good, damn good when properly used,
and installed.

I suspect there's rather more to HVAC than simply a "well Q/A'd AC".

phoo! HFAC. I couldn't find any specs for it online.


What I called HFAC is "Hospital Facility Armored Cable".

It's called different things, HCF AC, etc.

Just do a google search.

Enjoy,

tom

On Wed, 17 May 2006 19:12:51 -0400, wrote:

On Wed, 17 May 2006 17:51:05 -0400, Tom The Great
wrote:

Yeah that is what I said, but I was wondering if you put in a GFCI
breaker, does that open you up for using 3 prong receptacles.
Yes it does


Thank you!

I got a sec to check, 2005NEC 406.4(d)(3)(c) Says GFCI, not GFCI
receptacle.

Thanks,

tom