In my early 1950s house, I decided to upgrade the bathroom
outlet fixture to a GFCI, 20-amp circuit.

When removing the old, metal outlet box, I found that the
ground wire to the outlet was connected to a screw in the
back of the box. The separate bare wire coming down from
the attic, was "connected" to the box by a couple of turns
around one of the nails holding the box to the stud!

This surely wouldn't meet any code in the USA today (I don't
think), but it was obviously not a modification.

So either it met code at construction-time, or it was not
properly inspected during construction.

I'm curios as to which situation was true.

--
croy

On 11/11/2012 3:23 PM, croy wrote:
....

So either it met code at construction-time, or it was not
properly inspected during construction.

I'm curios as to which situation was true.

Neither--it of course would never be Code-compliant; it probably never
saw an inspector specifically.

--

"croy" wrote in message
...
In my early 1950s house, I decided to upgrade the bathroom
outlet fixture to a GFCI, 20-amp circuit.

When removing the old, metal outlet box, I found that the
ground wire to the outlet was connected to a screw in the
back of the box. The separate bare wire coming down from
the attic, was "connected" to the box by a couple of turns
around one of the nails holding the box to the stud!

This surely wouldn't meet any code in the USA today (I don't
think), but it was obviously not a modification.

So either it met code at construction-time, or it was not
properly inspected during construction.

I'm curios as to which situation was true.

--
croy

One thing the electrical codes have always required is an "approved"
connection whether soldered, clamped, twisted (via a wire nut) or screw.
Wrapping a wire around a steel nail, which could rust, would never have made
it. The intent, of course, is to have a reliable connection from the box to
ground.

Tomsic

On 11/11/2012 06:06 PM, .-. wrote:

"croy" wrote in message
...
In my early 1950s house, I decided to upgrade the bathroom
outlet fixture to a GFCI, 20-amp circuit.

When removing the old, metal outlet box, I found that the
ground wire to the outlet was connected to a screw in the
back of the box. The separate bare wire coming down from
the attic, was "connected" to the box by a couple of turns
around one of the nails holding the box to the stud!

This surely wouldn't meet any code in the USA today (I don't
think), but it was obviously not a modification.

So either it met code at construction-time, or it was not
properly inspected during construction.

I'm curios as to which situation was true.

--
croy

One thing the electrical codes have always required is an "approved"
connection whether soldered, clamped, twisted (via a wire nut) or screw.
Wrapping a wire around a steel nail, which could rust, would never have made
it. The intent, of course, is to have a reliable connection from the box to
ground.

Tomsic



When was the requirement for the boxes to be grounded actually
introduced? I'm just curious - my data point, house built in 1947 or 48
did not have any grounded boxes other than those provided by connection
to BX (house was a mix of exposed BX and concealed "rag" wiring.)
Clearly if an "early 1950s" house had grounds, it was somewhere in that
time frame that it was introduced.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

"Nate Nagel" wrote in message
...
On 11/11/2012 06:06 PM, .-. wrote:

"croy" wrote in message
...
In my early 1950s house, I decided to upgrade the bathroom
outlet fixture to a GFCI, 20-amp circuit.

When removing the old, metal outlet box, I found that the
ground wire to the outlet was connected to a screw in the
back of the box. The separate bare wire coming down from
the attic, was "connected" to the box by a couple of turns
around one of the nails holding the box to the stud!

This surely wouldn't meet any code in the USA today (I don't
think), but it was obviously not a modification.

So either it met code at construction-time, or it was not
properly inspected during construction.

I'm curios as to which situation was true.

--
croy

One thing the electrical codes have always required is an "approved"
connection whether soldered, clamped, twisted (via a wire nut) or screw.
Wrapping a wire around a steel nail, which could rust, would never have
made
it. The intent, of course, is to have a reliable connection from the box
to
ground.

Tomsic



When was the requirement for the boxes to be grounded actually introduced?
I'm just curious - my data point, house built in 1947 or 48 did not have
any grounded boxes other than those provided by connection to BX (house
was a mix of exposed BX and concealed "rag" wiring.) Clearly if an "early
1950s" house had grounds, it was somewhere in that time frame that it was
introduced.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Your "1950s" date sounds right, Nate. I don't have copies of the National
Electrical Code that go back that far, but that's when I remember 3-prong
outlets appearing. It took a while to change practice however. I had a
house that was built in 1958 that was wired with knob and tube - no ground
wires in that.

Tomsic

On Sun, 11 Nov 2012 22:24:00 -0500, ".-." wrote:


Your "1950s" date sounds right, Nate. I don't have copies of the National
Electrical Code that go back that far, but that's when I remember 3-prong
outlets appearing. It took a while to change practice however. I had a
house that was built in 1958 that was wired with knob and tube - no ground
wires in that.

Tomsic

My parents house that I was raised in, was built in 1951. It had NO
grounded outlets anywhere. The wiring was BX in the walls, and metal
EMT conduit in the basement. In the early 60's an electrician added
some circuits and put in grounded outlets on the new additional outlets,
and more when when a garage was built. When I was in my late teens, I
replaced the outlets in the basement by the workbench with grounded
ones, because I got sick of using ground adaptors on every power tool.
My father would not touch electrical stuff, so he asked me to also
change the one by the washer and dryer, and the ones by the kitchen
counter. Eventually I changed more of them in the house.

This says that it was *after* 1951 that grounded outlets became code.

On 11/12/2012 01:29, wrote:

This says that it was *after* 1951 that grounded outlets became code.

The 1962 NEC was the first to require all outlets to be grounded.

On Sun, 11 Nov 2012 13:23:05 -0800, croy wrote:

In my early 1950s house, I decided to upgrade the bathroom
outlet fixture to a GFCI, 20-amp circuit.

When removing the old, metal outlet box, I found that the
ground wire to the outlet was connected to a screw in the
back of the box. The separate bare wire coming down from
the attic, was "connected" to the box by a couple of turns
around one of the nails holding the box to the stud!

This surely wouldn't meet any code in the USA today (I don't
think), but it was obviously not a modification.

So either it met code at construction-time, or it was not
properly inspected during construction.

I'm curios as to which situation was true.

A lot of the older metal boxes did not have threaded holes for ground
screws. So, using a nail was all that was possible, unril they came out
with the clamps that snap over the edge if the box. If the nail is
tight, it's likely a good ground, but not allowed by code. In the past,
if I've had to work on old wiring and boxes without ground screw holes,
I opted to use a screw in place of a nail, and put a washer under the
screw head. Then wrap the wire under that washer. Again, it's not
allowed by code, but it works.

I dont know what was allowed by code in the old days, but there are
probably millions of boxes grounded just on a nail. Remember, the old
wiring did not use grounds, so it's not always easy to upgrade without
ripping out walls and stuff.

The correct way would be to drill a hole in the box, thread it, and
insert a ground screw.

On 11/11/2012 07:48 PM, wrote:
On Sun, 11 Nov 2012 13:23:05 -0800, croy wrote:

In my early 1950s house, I decided to upgrade the bathroom
outlet fixture to a GFCI, 20-amp circuit.

When removing the old, metal outlet box, I found that the
ground wire to the outlet was connected to a screw in the
back of the box. The separate bare wire coming down from
the attic, was "connected" to the box by a couple of turns
around one of the nails holding the box to the stud!

This surely wouldn't meet any code in the USA today (I don't
think), but it was obviously not a modification.

So either it met code at construction-time, or it was not
properly inspected during construction.

I'm curios as to which situation was true.

A lot of the older metal boxes did not have threaded holes for ground
screws. So, using a nail was all that was possible, unril they came out
with the clamps that snap over the edge if the box. If the nail is
tight, it's likely a good ground, but not allowed by code. In the past,
if I've had to work on old wiring and boxes without ground screw holes,
I opted to use a screw in place of a nail, and put a washer under the
screw head. Then wrap the wire under that washer. Again, it's not
allowed by code, but it works.

I dont know what was allowed by code in the old days, but there are
probably millions of boxes grounded just on a nail. Remember, the old
wiring did not use grounds, so it's not always easy to upgrade without
ripping out walls and stuff.

The correct way would be to drill a hole in the box, thread it, and
insert a ground screw.


which is not hard; Klein makes a tap tool with a screwdriver handle for
just this purpose. Have used it quite a few times for just this
application. (trying to use a standard tap with T-handle is difficult
due to the depth of the boxes, but you don't need a whole lot of torque
to thread the steel of a typical electrical box.)

I would, however, splice the ground wires on the cables entering the box
together, along with a long bare pigtail of the proper gauge, with a
wire nut. The pigtail then loops under the box's ground screw and then
is connected to the ground terminal of the device installed in the box.
If both of the ground wires coming from the cables are long enough,
you could loop one under the box's ground screw, the other under the
device's terminal, then splice with wire nut. This way all connections
are good and proper, and you don't have to mess with BS like trying to
shove two short wires under a single screw without a Sta-Kon.

Aside: Why don't spec grade "back wire" devices allow two ground wires
to be inserted under a single screw like the hots and neutrals?

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Sun, 11 Nov 2012 20:13:39 -0500, Nate Nagel
wrote:

which is not hard; Klein makes a tap tool with a screwdriver handle for
just this purpose. Have used it quite a few times for just this
application. (trying to use a standard tap with T-handle is difficult
due to the depth of the boxes, but you don't need a whole lot of torque
to thread the steel of a typical electrical box.)

That sounds like a handy tool.

I would, however, splice the ground wires on the cables entering the box
together, along with a long bare pigtail of the proper gauge, with a
wire nut. The pigtail then loops under the box's ground screw and then
is connected to the ground terminal of the device installed in the box.
If both of the ground wires coming from the cables are long enough,
you could loop one under the box's ground screw, the other under the
device's terminal, then splice with wire nut. This way all connections
are good and proper, and you don't have to mess with BS like trying to
shove two short wires under a single screw without a Sta-Kon.


The problem with old wiring is that there is often no bare wires. The
wiring is armoured cable (BX), or metal conduit. The conduit is
normally a good ground, but only the BX with the bare metal insert in
the cable is a decent ground. Aside from ripping the whole house apart,
one can only use what exists as a ground.


Aside: Why don't spec grade "back wire" devices allow two ground wires
to be inserted under a single screw like the hots and neutrals?

I fully agree, actually all devices *could* have more than one ground
screw to make wiring easier. At least two screws, since probably hanf
the outlets and switches feed at least 2 cables. (the source wire and
the wire that goes to the next fixture).

When I wire a box, I normally make one cable longer, than take the bare
and wrap it to the box screw near the entry point (box clamp). Then the
end of that bare wire goes to the outlet or device. If there are two or
more wires, that means more wirenuts. Which of course fills the box
faster and makes wiring harder.

nate

On Nov 12, 9:14*am, wrote:
On Sun, 11 Nov 2012 20:13:39 -0500, Nate Nagel
wrote:

which is not hard; Klein makes a tap tool with a screwdriver handle for
just this purpose. *Have used it quite a few times for just this
application. *(trying to use a standard tap with T-handle is difficult
due to the depth of the boxes, but you don't need a whole lot of torque
to thread the steel of a typical electrical box.)

That sounds like a handy tool.



I would, however, splice the ground wires on the cables entering the box
together, along with a long bare pigtail of the proper gauge, with a
wire nut. *The pigtail then loops under the box's ground screw and then
is connected to the ground terminal of the device installed in the box.
*If both of the ground wires coming from the cables are long enough,
you could loop one under the box's ground screw, the other under the
device's terminal, then splice with wire nut. *This way all connections
are good and proper, and you don't have to mess with BS like trying to
shove two short wires under a single screw without a Sta-Kon.

The problem with old wiring is that there is often no bare wires. *The
wiring is armoured cable (BX), or metal conduit. *The conduit is
normally a good ground, but only the BX with the bare metal insert in
the cable is a decent ground. *Aside from ripping the whole house apart,
one can only use what exists as a ground.

Aside: Why don't spec grade "back wire" devices allow two ground wires
to be inserted under a single screw like the hots and neutrals?

I fully agree, actually all devices *could* have more than one ground
screw to make wiring easier. *At least two screws, since probably hanf
the outlets and switches feed at least 2 cables. *(the source wire and
the wire that goes to the next fixture).

When I wire a box, I normally make one cable longer, than take the bare
and wrap it to the box screw near the entry point (box clamp). *Then the
end of that bare wire goes to the outlet or device. *If there are two or
more wires, that means more wirenuts. *Which of course fills the box
faster and makes wiring harder.

My, things are primitive in the USA.

On 11/12/2012 4:00 AM, harry wrote:
On Nov 12, 9:14 am, wrote:
On Sun, 11 Nov 2012 20:13:39 -0500, Nate Nagel
wrote:

which is not hard; Klein makes a tap tool with a screwdriver handle for
just this purpose. Have used it quite a few times for just this
application. (trying to use a standard tap with T-handle is difficult
due to the depth of the boxes, but you don't need a whole lot of torque
to thread the steel of a typical electrical box.)

That sounds like a handy tool.



I would, however, splice the ground wires on the cables entering the box
together, along with a long bare pigtail of the proper gauge, with a
wire nut. The pigtail then loops under the box's ground screw and then
is connected to the ground terminal of the device installed in the box.
If both of the ground wires coming from the cables are long enough,
you could loop one under the box's ground screw, the other under the
device's terminal, then splice with wire nut. This way all connections
are good and proper, and you don't have to mess with BS like trying to
shove two short wires under a single screw without a Sta-Kon.

The problem with old wiring is that there is often no bare wires. The
wiring is armoured cable (BX), or metal conduit. The conduit is
normally a good ground, but only the BX with the bare metal insert in
the cable is a decent ground. Aside from ripping the whole house apart,
one can only use what exists as a ground.

Aside: Why don't spec grade "back wire" devices allow two ground wires
to be inserted under a single screw like the hots and neutrals?

I fully agree, actually all devices *could* have more than one ground
screw to make wiring easier. At least two screws, since probably hanf
the outlets and switches feed at least 2 cables. (the source wire and
the wire that goes to the next fixture).

When I wire a box, I normally make one cable longer, than take the bare
and wrap it to the box screw near the entry point (box clamp). Then the
end of that bare wire goes to the outlet or device. If there are two or
more wires, that means more wirenuts. Which of course fills the box
faster and makes wiring harder.

My, things are primitive in the USA.


Yea, I'm having a heck of a time with this hand cranked computer and
carrier pigeons carrying IP packets back and forth from my service
provider. O_o

TDD

On Mon, 12 Nov 2012 03:14:11 -0600, wrote:

On Sun, 11 Nov 2012 20:13:39 -0500, Nate Nagel
wrote:

which is not hard; Klein makes a tap tool with a screwdriver handle for
just this purpose. Have used it quite a few times for just this
application. (trying to use a standard tap with T-handle is difficult
due to the depth of the boxes, but you don't need a whole lot of torque
to thread the steel of a typical electrical box.)

That sounds like a handy tool.

I would, however, splice the ground wires on the cables entering the box
together, along with a long bare pigtail of the proper gauge, with a
wire nut. The pigtail then loops under the box's ground screw and then
is connected to the ground terminal of the device installed in the box.
If both of the ground wires coming from the cables are long enough,
you could loop one under the box's ground screw, the other under the
device's terminal, then splice with wire nut. This way all connections
are good and proper, and you don't have to mess with BS like trying to
shove two short wires under a single screw without a Sta-Kon.


The problem with old wiring is that there is often no bare wires. The
wiring is armoured cable (BX), or metal conduit. The conduit is
normally a good ground, but only the BX with the bare metal insert in
the cable is a decent ground. Aside from ripping the whole house apart,
one can only use what exists as a ground.


Aside: Why don't spec grade "back wire" devices allow two ground wires
to be inserted under a single screw like the hots and neutrals?

I fully agree, actually all devices *could* have more than one ground
screw to make wiring easier. At least two screws, since probably hanf
the outlets and switches feed at least 2 cables. (the source wire and
the wire that goes to the next fixture).

Grounds are not supposed to be daisy-chained (neither are neutrals).

When I wire a box, I normally make one cable longer, than take the bare
and wrap it to the box screw near the entry point (box clamp). Then the
end of that bare wire goes to the outlet or device. If there are two or
more wires, that means more wirenuts. Which of course fills the box
faster and makes wiring harder.

On Sun, 18 Nov 2012 12:36:57 -0500, wrote:

On Sun, 18 Nov 2012 12:14:40 -0500, z wrote:

Grounds are not supposed to be daisy-chained (neither are neutrals).

You can chain a neutral through a device unless it is a multiwire
circuit. There is no rule at all about grounding conductors beyond

"Electrical equipment and wiring and other electrically conductive
material likely to become energized shall be installed in a manner
that creates a low-impedance circuit facilitating the operation of the
overcurrent device or ground detector for high-impedance grounded
systems."
If the device manufacturer provides 2 screws, you can chain through
that device. It is common to see the ground looped through the single
screw and continuing on to the next one.

I didn't say that it wasn't to code. OTOH, it's terrible practice. An
inspector I had would have failed me for using both neutral screws. He
probably would have condemned the place had I daisy-chained grounds.

On 11/11/2012 7:13 PM, Nate Nagel wrote:

Aside: Why don't spec grade "back wire" devices allow two ground wires
to be inserted under a single screw like the hots and neutrals?


My guess is that if you replace the receptacle while the circuit is live
you break the ground downstream. The same is true of the neutral. You
can have a "hot" neutral or ground downstream. A hot neutral is not
likely to be a problem (except for the person changing the receptacle).
A hot ground, even for a short time, can be fatal.

For multiwire (Edison) circuits you are not allowed to connect the
neutral through the receptacle. It has to be spliced separately, and a
single neutral wire connects to the receptacle. If replace the
receptacle hot, and break the neutral, one downstream leg-to-neutral can
wind up at 240V and the other 0V.

On Sun, 11 Nov 2012 18:48:13 -0600,
wrote:


A lot of the older metal boxes did not have threaded holes for ground
screws.

This one did, but was only used to connect the outlet ground
lug to the outlet box.

So, using a nail was all that was possible, unril they came out
with the clamps that snap over the edge if the box. If the nail is
tight, it's likely a good ground, but not allowed by code.

The thought of dissimilar metals seems like a sure miss to
me (for a dependable connection). And the fact that a nail
used to hold the outlet box to the stud is never going to be
dependably tight--the box gets pushed and pulled every time
something is plugged in or unplugged. Especially when the
studs are soft redwood.

When I wired up my garage, I put 2x4s spanning between
studs, and screwed the boxes to those. None of those boxes
are wiggly at all!


In the past,
if I've had to work on old wiring and boxes without ground screw holes,
I opted to use a screw in place of a nail, and put a washer under the
screw head. Then wrap the wire under that washer. Again, it's not
allowed by code, but it works.

It works long enough to get paid for the job, anyway.


I dont know what was allowed by code in the old days, but there are
probably millions of boxes grounded just on a nail. Remember, the old
wiring did not use grounds, so it's not always easy to upgrade without
ripping out walls and stuff.

In this case, the separate, bare ground was wrapped around
the nail used to mount the box to the stud. This couldn't
have been done post-construction, as there is no evidence of
the sheetrock having been disturbed, and the nail is
otherwise innaccessible.


The correct way would be to drill a hole in the box, thread it, and
insert a ground screw.

And have a direct connection from ground to the recepticle,
as opposed to chaining the ground thru the box (says this
untrained homeowner).

Copper to steel still sounds like a questionable technique
to me, even tho I know it is still the most common (only?)
way of grounding steel boxes. The slightest bit of
moisture.... And if you live near the ocean?

--
croy