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Default 2 prong to 3 prong outlet conversion?

We just bought a new house and want to upgrade the electrical system,
some of which was done in the 60's when the house was built. The vast
majority of the electrical outlets have only 2 wires, the ground
terminal is missing.

Some of the outlets are in the basement, where the wiring is partially
accessible however.

Is it legal (according to the electrical code) for me to change the
outlet to a more modern 3 prong type and to obtain a ground from a
nearby copper pipe or from one of the nearby plugs that already have a
3 prong outlet???? I notice the previous owner did this in several
locations, but I need to know if it's legal to obtain a ground in this
manner???

We live in Maine, but belive the National Code is the one that has
jurisdiction.

Thanks,

A
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Default 2 prong to 3 prong outlet conversion?


Ari wrote:
We just bought a new house and want to upgrade the electrical system,
some of which was done in the 60's when the house was built. The vast
majority of the electrical outlets have only 2 wires, the ground
terminal is missing.

Some of the outlets are in the basement, where the wiring is partially
accessible however.

Is it legal (according to the electrical code) for me to change the
outlet to a more modern 3 prong type and to obtain a ground from a
nearby copper pipe or from one of the nearby plugs that already have a
3 prong outlet???? I notice the previous owner did this in several
locations, but I need to know if it's legal to obtain a ground in this
manner???

We live in Maine, but belive the National Code is the one that has
jurisdiction.

Thanks,

A


Might not be necessary; if the wiring is vintage 60s, it's most likely
grounded via conduit or via BX cable. No?

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Default 2 prong to 3 prong outlet conversion?

On Mon, 10 Jul 2006 15:39:42 -0400, Ari wrote:

We just bought a new house and want to upgrade the electrical system,
some of which was done in the 60's when the house was built. The vast
majority of the electrical outlets have only 2 wires, the ground
terminal is missing.

Some of the outlets are in the basement, where the wiring is partially
accessible however.

Is it legal (according to the electrical code) for me to change the
outlet to a more modern 3 prong type and to obtain a ground from a
nearby copper pipe or from one of the nearby plugs that already have a
3 prong outlet???? I notice the previous owner did this in several
locations, but I need to know if it's legal to obtain a ground in this
manner???

We live in Maine, but belive the National Code is the one that has
jurisdiction.


You should not use the plumbing system as the path-to-ground
for your outlets, no. The simple "solution" is to replace
the receptacles with GFCI outlets, and mark them "no equipment
ground", (which labels ought to come with the recepticles).
This will get you within shouting distance of the same level
of protection.

The complex solution is to run completely new wire.

An intermediate solution is to pull a separate ground
wire, and run it back to your service panel.
If you do that, you want to make sure that no ground
wire serves the devices on more than on circut, and
that each one is big enough to handle the circut it's
on.

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Default 2 prong to 3 prong outlet conversion?


Might not be necessary; if the wiring is vintage 60s, it's most likely
grounded via conduit or via BX cable. No?



No, there are no ground wires in any on the junction boxes or in the
outlet boxes. I've pulled apart a bunch of them to make sure. The
cable is 2 conductor, no ground, no metal conduit. It just looks like
Romex, except there is no third wire in it.

The boxes are all metal and have the grounding screw, but of course,
there is no third wire to attach to the grounding screw. So, the boxes
are 'floating'.

Can I run a large gauge single ground wire back to the box, and then
attach individual ground wires from each outlet to the 'bus' wire?

There is a very large copper wire already going to ground on the city
water meter, can I attach other wires to this large ground wire since
it goes to a true ground?

Does the 'ground' truely have to go to the ground in the panel?
Shouldn't any dedicated ground source be just as goodas the panel
ground (such as a ground rod driven in hte ground)?

I understand the gfi outlet solution (labeling each outlet to indicate
there is no ground). I even understand WHY this is OK (because the GFI
outlet senses current in both the neutral and the hot wire, and
immediately trips if there is a difference between the current in each
wire). But, I'd much rather have a real ground, if possible.

A bus (or is it buss) solution is not ok?

Thanks,

A
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Default 2 prong to 3 prong outlet conversion?

Ari wrote:

There is a very large copper wire already going to ground on the city
water meter, can I attach other wires to this large ground wire since
it goes to a true ground?


Yes you can. That is a "grounding electrode conductor", and it is
connected to the panel ground. Get a big copper split-bolt connector
and use it to fasten your new grounding wires to that big wire..

Does the 'ground' truely have to go to the ground in the panel?
Shouldn't any dedicated ground source be just as goodas the panel
ground (such as a ground rod driven in hte ground)?


It has to be electrically equivalent to the panel ground, not "just as
good". IIRC, the panel itself, a grounding electrode conductor (big
wire connecting the panel to a ground electrode), and the metal service
raceway (conduit feeding the main panel, assuming it's metal conduit)
are all OK places to connect your equipment grounding wires.

A long time ago, it was permissible to use the nearest cold water pipe
to make a ground, but no longer (someone might replace part of it with
plastic pipe. Also, the plumber could get electrocuted when he cuts the
metal pipe if there is current flowing thru it due to a fault.)

Best regards,
Bob


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Default 2 prong to 3 prong outlet conversion?



Ari wrote:

There is a very large copper wire already going to ground on the city
water meter, can I attach other wires to this large ground wire since
it goes to a true ground?


Yes you can. That is a "grounding electrode conductor", and it is
connected to the panel ground. Get a big copper split-bolt connector
and use it to fasten your new grounding wires to that big wire..


Thanks Bob!

Any caveats to using the big bus wire as a ground? For instance, the
wire is copper, multi-stranded and appears to be 1/4 inch in diameter,
or slightly larger. Do I have to worry about the current carrying
capacity of that large gauge wire if it is hooked up to many
outlets??? For instance, if the large bus wire is capable of carrying
100 amps, do I need to insure that no more than 5 20 amp outlets are
grounded through that wire???

I did find 2 of the recently upgraded GFI outlets that were grounded
to the copper plumbing and thought I'd better ask on here! Such a
shame, the large copper grounding wire that runs to the water meter
ground is right next to the copper plumbing lines! It would have been
so easy to connect those grounds to the copper wire!!!! I have no idea
why the previous owner used the copper plumbing with the large cooper
ground wire running so close.


Does the 'ground' truely have to go to the ground in the panel?
Shouldn't any dedicated ground source be just as goodas the panel
ground (such as a ground rod driven in hte ground)?


It has to be electrically equivalent to the panel ground, not "just as
good". IIRC, the panel itself, a grounding electrode conductor (big
wire connecting the panel to a ground electrode), and the metal service
raceway (conduit feeding the main panel, assuming it's metal conduit)
are all OK places to connect your equipment grounding wires.


OK, now that you mention it, there is some nearby wiring that was part
of an addition they did just before deciding to sell the house. The
new wiring is all metal conduit protected. Is the metal conduit of the
newer wiring ok to use as a ground for the nearby legacy outlets? Or,
do I have to run a ground wire inside a junction box and connect my
ground wire to the existing ground in the conduit junction box?

Thanks so much for the info.

Regards

A
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Default 2 prong to 3 prong outlet conversion?

Ari wrote:

Ari wrote:
There is a very large copper wire already going to ground on the
city water meter, can I attach other wires to this large ground
wire since it goes to a true ground?

Yes you can. That is a "grounding electrode conductor", and it is
connected to the panel ground. Get a big copper split-bolt
connector and use it to fasten your new grounding wires to that big
wire..


Thanks Bob!

Any caveats to using the big bus wire as a ground? For instance, the
wire is copper, multi-stranded and appears to be 1/4 inch in
diameter, or slightly larger. Do I have to worry about the current
carrying capacity of that large gauge wire if it is hooked up to many
outlets??? For instance, if the large bus wire is capable of
carrying 100 amps, do I need to insure that no more than 5 20 amp
outlets are grounded through that wire???


No, you don't care about the current capacity of that wire.

I did find 2 of the recently upgraded GFI outlets that were grounded
to the copper plumbing and thought I'd better ask on here! Such a
shame, the large copper grounding wire that runs to the water meter
ground is right next to the copper plumbing lines! It would have been
so easy to connect those grounds to the copper wire!!!! I have no
idea why the previous owner used the copper plumbing with the large
cooper ground wire running so close.


That was common practice 30 years ago. (I'm guessing about the "30"
part, but it's good guess, and a ballpark figure anyway.)

Does the 'ground' truely have to go to the ground in the panel?
Shouldn't any dedicated ground source be just as goodas the panel
ground (such as a ground rod driven in hte ground)?

It has to be electrically equivalent to the panel ground, not "just
as good". IIRC, the panel itself, a grounding electrode conductor
(big wire connecting the panel to a ground electrode), and the
metal service raceway (conduit feeding the main panel, assuming
it's metal conduit) are all OK places to connect your equipment
grounding wires.


OK, now that you mention it, there is some nearby wiring that was
part of an addition they did just before deciding to sell the house.
The new wiring is all metal conduit protected. Is the metal conduit
of the newer wiring ok to use as a ground for the nearby legacy
outlets? Or, do I have to run a ground wire inside a junction box and
connect my ground wire to the existing ground in the conduit junction
box?


No. The metal conduit is probably a good enough ground for the circuits
that run in it (or it might not if it wasn't installed well.) It's not
good enough for grounding additional circuits.

BTW, you don't really have to ground *everything*. I live in a 60
year-old house where all the basement wiring is grounded and none of the
upstairs is grounded. I've been adding grounds over the years when I
need one or when it's convenient because of another repair that I'm
doing. I'm trying to get one or two properly-grounded outlets in each
room. Think about it; do you really need a ground when you plug in your
clock radio or a lamp? Of course not. But you want someplace to plug
in your grounded vacuum cleaner (etc.) occasionally.

Bob
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Default 2 prong to 3 prong outlet conversion?

Good idea to GFI protect the basement outlets, except any for a
freezer/refrigerator.

"Ari" wrote in message
...
We just bought a new house and want to upgrade the electrical system,
some of which was done in the 60's when the house was built. The vast
majority of the electrical outlets have only 2 wires, the ground
terminal is missing.

Some of the outlets are in the basement, where the wiring is partially
accessible however.

Is it legal (according to the electrical code) for me to change the
outlet to a more modern 3 prong type and to obtain a ground from a
nearby copper pipe or from one of the nearby plugs that already have a
3 prong outlet???? I notice the previous owner did this in several
locations, but I need to know if it's legal to obtain a ground in this
manner???

We live in Maine, but belive the National Code is the one that has
jurisdiction.

Thanks,

A



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Default 2 prong to 3 prong outlet conversion?


Is it legal (according to the electrical code) for me to change the
outlet to a more modern 3 prong type and to obtain a ground from a
nearby copper pipe or from one of the nearby plugs that already have a
3 prong outlet???? I notice the previous owner did this in several
locations, but I need to know if it's legal to obtain a ground in this
manner???

We live in Maine, but belive the National Code is the one that has
jurisdiction.


If you are planning to pull a ground wire back to the panel, you might
as well just plan on rewiring the outlets properly and legally with
new grounded cable. Any separate ground that you run is going to be
a kluge install and most likely would not pass code with an honest and
knowlegable electrical inspector. Not being code compliant can
affect your liability and fire insurance coverage.

As another poster says, if you don't want to go to all that trouble
and expense, putting in the GFCI's with the appropriate labels would
be the easy (and perfectly legal) way to go.

Beachcomber



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Default 2 prong to 3 prong outlet conversion?

Beachcomber wrote:
Is it legal (according to the electrical code) for me to change the
outlet to a more modern 3 prong type and to obtain a ground from a
nearby copper pipe or from one of the nearby plugs that already have a
3 prong outlet???? I notice the previous owner did this in several
locations, but I need to know if it's legal to obtain a ground in this
manner???

We live in Maine, but belive the National Code is the one that has
jurisdiction.


If you are planning to pull a ground wire back to the panel, you might
as well just plan on rewiring the outlets properly and legally with
new grounded cable. Any separate ground that you run is going to be
a kluge install and most likely would not pass code with an honest and
knowlegable electrical inspector. Not being code compliant can
affect your liability and fire insurance coverage.


I haven't checked the most recent revision of the code to make sure it's
still there, but the code specifically allows you to run a separate
ground wire when upgrading old work. Think about it; the old ungrounded
wiring is code compliant because there was no grounded requirement when
it was installed. Adding a supplemental grounding wire can only make it
safer (assuming the grounding wire goes back to the panel or grounding
electrode system so a fault can't energize another circuit.)

Bob


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Default 2 prong to 3 prong outlet conversion?

Replace ALL the wires and be done with it......


On Mon, 10 Jul 2006 17:09:17 -0400, Ari wrote:


Might not be necessary; if the wiring is vintage 60s, it's most likely
grounded via conduit or via BX cable. No?



No, there are no ground wires in any on the junction boxes or in the
outlet boxes. I've pulled apart a bunch of them to make sure. The
cable is 2 conductor, no ground, no metal conduit. It just looks like
Romex, except there is no third wire in it.

The boxes are all metal and have the grounding screw, but of course,
there is no third wire to attach to the grounding screw. So, the boxes
are 'floating'.

Can I run a large gauge single ground wire back to the box, and then
attach individual ground wires from each outlet to the 'bus' wire?

There is a very large copper wire already going to ground on the city
water meter, can I attach other wires to this large ground wire since
it goes to a true ground?

Does the 'ground' truely have to go to the ground in the panel?
Shouldn't any dedicated ground source be just as goodas the panel
ground (such as a ground rod driven in hte ground)?

I understand the gfi outlet solution (labeling each outlet to indicate
there is no ground). I even understand WHY this is OK (because the GFI
outlet senses current in both the neutral and the hot wire, and
immediately trips if there is a difference between the current in each
wire). But, I'd much rather have a real ground, if possible.

A bus (or is it buss) solution is not ok?

Thanks,

A


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Default 2 prong to 3 prong outlet conversion?

On Tue, 11 Jul 2006 04:06:02 GMT, "peter" wrote:

An intermediate solution is to pull a separate ground
wire, and run it back to your service panel.
If you do that, you want to make sure that no ground
wire serves the devices on more than on circut, and
that each one is big enough to handle the circut it's
on.


So to serve more than one circuit, you need to pull more than one ground
wire? Wouldn't it work just as well to pull a thicker ground wire?


Probably. Esp. if you use 10 AWG wire. I mean, how likely
are you the get three simultaneous high-resistance shorts
from the same leg of your panel?

But I know that the the former works, is safe,
and is legal, and I don't know any of that for sure about
the latter.

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Default 2 prong to 3 prong outlet conversion?

Goedjn wrote:
On Tue, 11 Jul 2006 04:06:02 GMT, "peter" wrote:

An intermediate solution is to pull a separate ground
wire, and run it back to your service panel.
If you do that, you want to make sure that no ground
wire serves the devices on more than on circut, and
that each one is big enough to handle the circut it's
on.

So to serve more than one circuit, you need to pull more than one ground
wire? Wouldn't it work just as well to pull a thicker ground wire?


Probably. Esp. if you use 10 AWG wire. I mean, how likely
are you the get three simultaneous high-resistance shorts
from the same leg of your panel?

But I know that the the former works, is safe,
and is legal, and I don't know any of that for sure about
the latter.


Equipment Grounding Conductors (EGCs) are sized for the size of the
largest Over Current Protective Device supplying the conductors in a
given box or other enclosure. As an extreme example lets use a junction
box for the kitchen and laundry circuits in an apartment. If the box
contains a fifty ampere stove circuit, a thirty ampere dryer circuit, a
twenty ampere laundry circuit, a twenty ampere multiwire kitchen counter
top circuits, a fifteen ampere multi wire dishwasher and disposal
circuit, and a fifteen ampere multiwire refrigerator and microwave oven
circuit it still only needs one equipment grounding conductor. That EGC
is sized for the fifty ampere breaker for the stove. The only reason
that the US NEC would require you to increase the size of the EGC is if
you increased the size of the current carrying conductors to compensate
for voltage drop. It just is not likely that there will be simultaneous
faults on two or more of the circuits that EGC was installed to protect.
--
Tom Horne

Well we aren't no thin blue heroes and yet we aren't no blackguards to.
We're just working men and woman most remarkable like you.
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Default 2 prong to 3 prong outlet conversion?

On Tue, 11 Jul 2006 03:57:40 GMT, AZ Nomad
wrote:

On Mon, 10 Jul 2006 20:53:02 -0500, zxcvbob wrote:
I haven't checked the most recent revision of the code to make sure it's
still there, but the code specifically allows you to run a separate
ground wire when upgrading old work. Think about it; the old ungrounded
wiring is code compliant because there was no grounded requirement when
it was installed. Adding a supplemental grounding wire can only make it
safer (assuming the grounding wire goes back to the panel or grounding
electrode system so a fault can't energize another circuit.)


Anything you touch is going to have to meet current code and the old wiring
probably won't if it's sixty years old. If you're going to pull a
ground through your walls, pulling new wiring isn't much more trouble.



Thank you all for commenting, I appreciate all the info!

I went down in the basement and pulled the cover off the entrance
panel. The inspection I did was very interesting, especially in light
of all the comments I've received to this post.

The large (existing) ground wire that goes to the ground rod near the
water main entrance IS the system ground for the electrical panel!!!!!
Although the panel is on one end of the house and the water main is on
the opposite end, it appears the original installer ran 50 feet of
large gauge copper across the middle of the basement in order to
ground the electrical service entrance panel.

So, that big ole copper wire that is very accessible should make a
fine ground!

Regarding the comments by some that I should just rip out the old 2
conductor wire and install 3 conductor wire in it's place..... do keep
in mind that the basement is finished, and gaining access to all the
wires that feed the house would require a major demolition and
restoration after the new wires were run. Not very practical::
However, adding a ground wire is much more practical because the added
ground wire doesn't have to follow the path of the original 2
conductor wiring.

Again, thanks to all who commented, I'll post an update here later on.

Regards,

A
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