Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach more
than one wire to each screw. I haven't been able to locate anything about
that in the 2008 National Electrical Code. It may be in there, but so far,
I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet receptacles
have two silver screws, two gold screws, and only one green grounding screw.
And that started me wondering, "Why aren't there two green grounding
screws?" For outlets that are in the middle of a circuit, there are
typically six wires in the outlet box -- two black, two white, and two
grounds. So, wouldn't it be easier if the receptacle had 6 screws? -- two
for the two black wires, two for the two white wires, and two for the two
ground wires?

Is it possible that the code allows two ground wires to be connected to the
one green grounding screw, but does not permit two wires per screw for the
white and black wires?

On 2/9/2009 9:24 PM RonABC spake thus:

Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach more
than one wire to each screw. I haven't been able to locate anything about
that in the 2008 National Electrical Code. It may be in there, but so far,
I haven't been able to find it.

I don't have the answer to this, and would like to know what (if
anything) the NEC has to say about it.

My own guideline is only 1 wire per screw, including ground screws: use
pigtails when more connections are needed. No need to ask for trouble.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

RonABC wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach
more than one wire to each screw. I haven't been able to locate
anything about that in the 2008 National Electrical Code. It may be in
there, but so far, I haven't been able to find it.

It may be a function of how the devices are designed rather than an NEC
ruling. If they were not designed and/or UL listed to have more than one
wire that in itself I believe would fall under some general NEC
guidelines. But not sure what section?



Part of why I am curious is that I notice that typical outlet
receptacles have two silver screws, two gold screws, and only one green
grounding screw. And that started me wondering, "Why aren't there two
green grounding screws?" For outlets that are in the middle of a
circuit, there are typically six wires in the outlet box -- two black,
two white, and two grounds. So, wouldn't it be easier if the receptacle
had 6 screws? -- two for the two black wires, two for the two white
wires, and two for the two ground wires?

Is it possible that the code allows two ground wires to be connected to
the one green grounding screw, but does not permit two wires per screw
for the white and black wires?

I am pretty sure you must wirenut the grounds. Using the special green
wirenuts with the feed hole makes this much easier.
As far as I know NEC does not require pigtails on the other wires but
some local codes do. Pigtails are better as a device failure is not as
likely to take out other devices down stream.

I prefer back feed type outlets which will take as many as 4 wires on
each side. Not as good as using pigtails but better and much easier
than wrapping wires around screws.

On occasion I will feed 2+ outlets or switches with a single wire. I
strip enough insulation off to wrap around a screw then continue the
same wire to the next outlet/switch.

Kevin

RonABC wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach
more than one wire to each screw. I haven't been able to locate
anything about that in the 2008 National Electrical Code. It may be in
there, but so far, I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet
receptacles have two silver screws, two gold screws, and only one green
grounding screw. And that started me wondering, "Why aren't there two
green grounding screws?" For outlets that are in the middle of a
circuit, there are typically six wires in the outlet box -- two black,
two white, and two grounds. So, wouldn't it be easier if the receptacle
had 6 screws? -- two for the two black wires, two for the two white
wires, and two for the two ground wires?

Is it possible that the code allows two ground wires to be connected to
the one green grounding screw, but does not permit two wires per screw
for the white and black wires?

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

s

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

RonABC wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach
more than one wire to each screw. I haven't been able to locate
anything about that in the 2008 National Electrical Code. It may be in
there, but so far, I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet
receptacles have two silver screws, two gold screws, and only one green
grounding screw. And that started me wondering, "Why aren't there two
green grounding screws?" For outlets that are in the middle of a
circuit, there are typically six wires in the outlet box -- two black,
two white, and two grounds. So, wouldn't it be easier if the receptacle
had 6 screws? -- two for the two black wires, two for the two white
wires, and two for the two ground wires?

Is it possible that the code allows two ground wires to be connected to
the one green grounding screw, but does not permit two wires per screw
for the white and black wires?


If the receptacle had 2 green screws, or if you attached two wires to
the one screw, removing the receptacle would leave all the downstream
devices ungrounded until you hook it back up. With only one ground wire
going to it, the downstream devices are not dependent on it for their
grounds.

(I too *love* those heavy-duty back-wired outlets with all the clamp
terminals on the back. They work great for tying a bunch of cables
together -- but not the ground conductors.)

Bob

On Tue, 10 Feb 2009 00:24:10 -0500, "RonABC" wrote:

Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach more
than one wire to each screw. I haven't been able to locate anything about
that in the 2008 National Electrical Code. It may be in there, but so far,
I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet receptacles
have two silver screws, two gold screws, and only one green grounding screw.
And that started me wondering, "Why aren't there two green grounding
screws?" For outlets that are in the middle of a circuit, there are
typically six wires in the outlet box -- two black, two white, and two
grounds. So, wouldn't it be easier if the receptacle had 6 screws? -- two
for the two black wires, two for the two white wires, and two for the two
ground wires?

Is it possible that the code allows two ground wires to be connected to the
one green grounding screw, but does not permit two wires per screw for the
white and black wires?


One wire, one screw. Not sure how two wires would even fit under one
screw, and if you did it would probably not be very secure. Sometimes
you have to use a pigtail. For most electrical outlets there are two
screws for the hot, two screws for the neutral, and one for the
ground.

"RonABC" wrote in message
...
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach more
than one wire to each screw. I haven't been able to locate anything about
that in the 2008 National Electrical Code. It may be in there, but so
far, I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet receptacles
have two silver screws, two gold screws, and only one green grounding
screw. And that started me wondering, "Why aren't there two green
grounding screws?" For outlets that are in the middle of a circuit, there
are typically six wires in the outlet box -- two black, two white, and two
grounds. So, wouldn't it be easier if the receptacle had 6 screws? -- two
for the two black wires, two for the two white wires, and two for the two
ground wires?

Is it possible that the code allows two ground wires to be connected to
the one green grounding screw, but does not permit two wires per screw for
the white and black wires?

There are a couple of code sections that would apply: Mostly in section 110
that require equipment be installed as per manufacturer instructions,
installed in a workmanlike manner, also 110.14A, which mentions that
terminals for more than one conductor shall be so identified

In article on Mon,
09 Feb 2009 22:47:38 -0800, David Nebenzahl wrote:

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.

By placing the receptacle in parallel with the circuit by pigtailing,
downstream outlets are unaffected by a problem with the receptacle, or
its outright removal.

--
Seth Goodman

On Feb 10, 12:24*am, "RonABC" wrote:
*So, wouldn't it be easier if the receptacle had 6 screws? -- two
for the two black wires, two for the two white wires, and two for the two
ground wires?

Is it possible that the code allows two ground wires to be connected to the
one green grounding screw, but does not permit two wires per screw for the
white and black wires?

No, the grounds are bare so it is easy to twist them together in the
back of the box and cut one off short. Then you hook the remaining
wire over the single green screw and tighten it down.

For fixtures where you "need" to connect two wires to a single screw,
take a short length of same-colored wire and bug it on to the two
wires as a pigtail using a crimped Buchanan connector or a wire nut.

RBM wrote:
"RonABC" wrote in message
...
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

There are a couple of code sections that would apply: Mostly in
section 110 that require equipment be installed as per manufacturer
instructions, installed in a workmanlike manner, also 110.14A, which
mentions that terminals for more than one conductor shall be so
identified.

Thanks. I think that's it. I don't think I've ever seen anything on any
electrical terminals that identify them as being for more than one
conductor, but I'll have to try looking at different devices and maybe the
manufacturer specifications for each device.

wrote:
On Feb 10, 12:24 am, "RonABC" wrote:

Is it possible that the code allows two ground wires to be connected
to the one green grounding screw, but does not permit two wires per
screw for the white and black wires?

No, the grounds are bare so it is easy to twist them together in the
back of the box and cut one off short. Then you hook the remaining
wire over the single green screw and tighten it down.

I assume that you mean twist them together using a wire nut (such as a green
one with a hole in the center), since just twisting them together without
one doesn't meet the code.

Also, if the wire that is cut off short leaves it with less than 6 inches of
wire in the box, that would not meet the code requirements.

zxcvbob wrote:
RonABC wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach
more than one wire to each screw. I haven't been able to locate
anything about that in the 2008 National Electrical Code. It may be
in there, but so far, I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet
receptacles have two silver screws, two gold screws, and only one
green grounding screw. And that started me wondering, "Why aren't
there two green grounding screws?" For outlets that are in the middle
of a circuit, there are typically six wires in the outlet box -- two
black, two white, and two grounds. So, wouldn't it be easier if the
receptacle had 6 screws? -- two for the two black wires, two for the
two white wires, and two for the two ground wires?

Is it possible that the code allows two ground wires to be connected
to the one green grounding screw, but does not permit two wires per
screw for the white and black wires?


If the receptacle had 2 green screws, or if you attached two wires to
the one screw, removing the receptacle would leave all the downstream
devices ungrounded until you hook it back up. With only one ground wire
going to it, the downstream devices are not dependent on it for their
grounds.

Yes. The code requirement is at 250.148-B.

For a multiwire branch circuit (with a common neutral), if you break the
neutral while the circuit is hot the downstream voltages can shift. As
above, I believe the neutral has to be spliced, with a single wire to a
receptacle. (Briefly looking, I couldn't find a code requirement.)

--
bud--

On 2/10/2009 5:37 AM Seth Goodman spake thus:

In article on Mon,
09 Feb 2009 22:47:38 -0800, David Nebenzahl wrote:

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.

By placing the receptacle in parallel with the circuit by pigtailing,
downstream outlets are unaffected by a problem with the receptacle, or
its outright removal.

But the only problem with the receptacle that could affect downstream
devices would be if the metal "bridge" between the two screws somehow
burned or melted out; pretty unlikely to happen. I still think this is a
perfectly good wiring method.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

"RonABC" wrote in message
...
RBM wrote:
"RonABC" wrote in message
...
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

There are a couple of code sections that would apply: Mostly in
section 110 that require equipment be installed as per manufacturer
instructions, installed in a workmanlike manner, also 110.14A, which
mentions that terminals for more than one conductor shall be so
identified.

Thanks. I think that's it. I don't think I've ever seen anything on any
electrical terminals that identify them as being for more than one
conductor, but I'll have to try looking at different devices and maybe the
manufacturer specifications for each device.

Personally, I'm curious about receptacles with screw clamps. Each clamp has
two holes where wires can be inserted, and there are 4 clamps. That could be
one pile of wires. I prefer to use pigtails on any receptacle with more than
four wires.

bud-- wrote:

Yes. The code requirement is at 250.148-B.


Thanks. Apparently, that is the exact code requirement that I was wondering
about.

Here's what is says (from the 2008 National Electrical Code):

"250.148(B) Grounding Continuity. The arrangement of grounding connections
shall be such that the disconnection or the removal of a receptacle,
luminaire, or other device fed from the box does not interfere with or
interrupt the grounding continuity."

"bud--" wrote in message
...
zxcvbob wrote:
RonABC wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach
more than one wire to each screw. I haven't been able to locate
anything about that in the 2008 National Electrical Code. It may be in
there, but so far, I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet
receptacles have two silver screws, two gold screws, and only one green
grounding screw. And that started me wondering, "Why aren't there two
green grounding screws?" For outlets that are in the middle of a
circuit, there are typically six wires in the outlet box -- two black,
two white, and two grounds. So, wouldn't it be easier if the receptacle
had 6 screws? -- two for the two black wires, two for the two white
wires, and two for the two ground wires?

Is it possible that the code allows two ground wires to be connected to
the one green grounding screw, but does not permit two wires per screw
for the white and black wires?


If the receptacle had 2 green screws, or if you attached two wires to the
one screw, removing the receptacle would leave all the downstream devices
ungrounded until you hook it back up. With only one ground wire going to
it, the downstream devices are not dependent on it for their grounds.

Yes. The code requirement is at 250.148-B.

For a multiwire branch circuit (with a common neutral), if you break the
neutral while the circuit is hot the downstream voltages can shift. As
above, I believe the neutral has to be spliced, with a single wire to a
receptacle. (Briefly looking, I couldn't find a code requirement.)

--
bud--

300.13

David Nebenzahl wrote:
On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.



You're not misunderstanding.

to daisy chain from outlet to outlet using the double set of screws will
lead to trouble down the line. Especially if you have to take an outlet
out of the mix. Then you'd be killing everyone down stream also.

s

On 2/10/2009 11:26 AM RBM spake thus:

"RonABC" wrote in message
...

RBM wrote:

"RonABC" wrote in message
...

Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

There are a couple of code sections that would apply: Mostly in
section 110 that require equipment be installed as per manufacturer
instructions, installed in a workmanlike manner, also 110.14A, which
mentions that terminals for more than one conductor shall be so
identified.

Thanks. I think that's it. I don't think I've ever seen anything on any
electrical terminals that identify them as being for more than one
conductor, but I'll have to try looking at different devices and maybe the
manufacturer specifications for each device.

Personally, I'm curious about receptacles with screw clamps. Each clamp has
two holes where wires can be inserted, and there are 4 clamps. That could be
one pile of wires. I prefer to use pigtails on any receptacle with more than
four wires.

Pretty much 6 of one and half a dozen of the other, isn't it?

Besides, by using the clamps, you'd reduce the volume of stuff in the
box by cutting down on the number of wire nuts, which take up space.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

On 2/10/2009 6:32 PM Steve Barker spake thus:

David Nebenzahl wrote:

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.

You're not misunderstanding.

to daisy chain from outlet to outlet using the double set of screws will
lead to trouble down the line. Especially if you have to take an outlet
out of the mix. Then you'd be killing everyone down stream also.

Why? When you work on the circuit, you need to disconnect the power
anyhow. If you need to remove an outlet, you can simply wire-nut the two
sets of wires together and everyone's back in business. I don't see the
problem.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

"David Nebenzahl" wrote in message
.com...
On 2/10/2009 11:26 AM RBM spake thus:

"RonABC" wrote in message
...

RBM wrote:

"RonABC" wrote in message
...

Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

There are a couple of code sections that would apply: Mostly in
section 110 that require equipment be installed as per manufacturer
instructions, installed in a workmanlike manner, also 110.14A, which
mentions that terminals for more than one conductor shall be so
identified.

Thanks. I think that's it. I don't think I've ever seen anything on
any electrical terminals that identify them as being for more than one
conductor, but I'll have to try looking at different devices and maybe
the manufacturer specifications for each device.

Personally, I'm curious about receptacles with screw clamps. Each clamp
has two holes where wires can be inserted, and there are 4 clamps. That
could be one pile of wires. I prefer to use pigtails on any receptacle
with more than four wires.

Pretty much 6 of one and half a dozen of the other, isn't it?

Besides, by using the clamps, you'd reduce the volume of stuff in the box
by cutting down on the number of wire nuts, which take up space.

That's true, but a lot of those clamps don't work particularly well with
solid conductors. Wire nuts installed correctly stay tight


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

On Feb 10, 9:29*am, "RonABC" wrote:
wrote:
On Feb 10, 12:24 am, "RonABC" wrote:

Is it possible that the code allows two ground wires to be connected
to the one green grounding screw, but does not permit two wires per
screw for the white and black wires?
No, the grounds are bare so it is easy to twist them together in the
back of the box and cut one off short. Then you hook the remaining
wire over the single green screw and tighten it down.

I assume that you mean twist them together using a wire nut (such as a green
one with a hole in the center), since just twisting them together without
one doesn't meet the code.

Also, if the wire that is cut off short leaves it with less than 6 inches of
wire in the box, that would not meet the code requirements.

This last statement is untrue. The code requires six inches of wire
in the box and extending at least three inches beyond the opening of
the box "for splices or the connection of luminaires (fixtures) or
devices." The code does not require that the conductors be that long
after the splices are made up and the devices installed. Requiring
that would overcrowd many boxes and cause more problems.

--
Tom Horne

On Feb 10, 10:18*pm, "RBM" wrote:
"David Nebenzahl" wrote in message

.com...



On 2/10/2009 11:26 AM RBM spake thus:

"RonABC" wrote in message
...

RBM wrote:

"RonABC" wrote in message
...

Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

There are a couple of code sections that would apply: Mostly in
section 110 that require equipment be installed as per manufacturer
instructions, installed in a workmanlike manner, also 110.14A, which
mentions that terminals for more than one conductor shall be so
identified.

Thanks. *I think that's it. *I don't think I've ever seen anything on
any electrical terminals that identify them as being for more than one
conductor, but I'll have to try looking at different devices and maybe
the manufacturer specifications for each device.

Personally, I'm curious about receptacles with screw clamps. Each clamp
has two holes where wires can be inserted, and there are 4 clamps. That
could be one pile of wires. I prefer to use pigtails on any receptacle
with more than four wires.

Pretty much 6 of one and half a dozen of the other, isn't it?

Besides, by using the clamps, you'd reduce the volume of stuff in the box
by cutting down on the number of wire nuts, which take up space.

That's true, but a lot of those clamps don't work particularly well with
solid conductors. Wire nuts installed correctly stay tight



I do not know which clamps you are referring to but that does not
reconcile with my experience in thirty three years in the craft. The
screw tightened clamps I have encountered have been fine on both
stranded and solid conductors and work better on stranded wire then
any screw binding connection without clamps ever would.

--
Tom Horne

On Feb 10, 12:24*am, "RonABC" wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach more
than one wire to each screw. *I haven't been able to locate anything about
that in the 2008 National Electrical Code. *It may be in *there, but so far,
I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet receptacles
have two silver screws, two gold screws, and only one green grounding screw.
And that started me wondering, "Why aren't there two green grounding
screws?" *For outlets that are in the middle of a circuit, there are
typically six wires in the outlet box -- two black, two white, and two
grounds. *So, wouldn't it be easier if the receptacle had 6 screws? -- two
for the two black wires, two for the two white wires, and two for the two
ground wires?

Is it possible that the code allows two ground wires to be connected to the
one green grounding screw, but does not permit two wires per screw for the
white and black wires?

"110.3 Examination, Identification, Installation, and Use of
Equipment.
(B) Installation and Use. Listed or labeled equipment shall be
installed and used in accordance with any instructions included in the
listing or labeling."

Information included with the listing can only be found in the
Building Materials List published by the testing laboratory. To be
included with the labeling the instructions must be contained within
the outlined area that contains the testing laboratory seal. An
Example would be "Underwriters Laboratory Listed. Copper Conductors
Only." The instructions within the package that say use only
manufacturers parts are not enforceable because they are not included
with the Listing. The testing laboratories list items that are
recognized for use with other manufacturers equipment. Thomas &
Bettes makes an extensive line of circuit breakers that have been
recognized for use in other manufacturers panels. Each manufacturer
specifically says use only our breakers. That is not an instruction
that is included in the listing or labeling and is therefore
unenforceable.

--
Tom Horne

In article , says...
"RonABC" wrote in message

There are a couple of code sections that would apply: Mostly in section 110
that require equipment be installed as per manufacturer instructions,
installed in a workmanlike manner, also 110.14A, which mentions that
terminals for more than one conductor shall be so identified


This seems correct. I always learned that the fallback for things is the
"Authority Having Jurisdiction". The NEC usually acts as the AHJ, but if
something is not specified by code (NEC or local), the AHJ is usually the
manufacturer. If they intended two wires to be clamped, the device would be so
designed and labelled.

--
Dennis

"Tom Horne" wrote in message
...
On Feb 10, 10:18 pm, "RBM" wrote:
"David Nebenzahl" wrote in message

.com...



On 2/10/2009 11:26 AM RBM spake thus:

"RonABC" wrote in message
...

RBM wrote:

"RonABC" wrote in message
...

Is there a specific electrical code that states how many wires can
be
attached per screw when wiring outlet receptacles?

There are a couple of code sections that would apply: Mostly in
section 110 that require equipment be installed as per manufacturer
instructions, installed in a workmanlike manner, also 110.14A, which
mentions that terminals for more than one conductor shall be so
identified.

Thanks. I think that's it. I don't think I've ever seen anything on
any electrical terminals that identify them as being for more than one
conductor, but I'll have to try looking at different devices and maybe
the manufacturer specifications for each device.

Personally, I'm curious about receptacles with screw clamps. Each clamp
has two holes where wires can be inserted, and there are 4 clamps. That
could be one pile of wires. I prefer to use pigtails on any receptacle
with more than four wires.

Pretty much 6 of one and half a dozen of the other, isn't it?

Besides, by using the clamps, you'd reduce the volume of stuff in the
box
by cutting down on the number of wire nuts, which take up space.

That's true, but a lot of those clamps don't work particularly well with
solid conductors. Wire nuts installed correctly stay tight



I do not know which clamps you are referring to but that does not
reconcile with my experience in thirty three years in the craft. The
screw tightened clamps I have encountered have been fine on both
stranded and solid conductors and work better on stranded wire then
any screw binding connection without clamps ever would.

--
Tom Horne

And in my thirty seven years in the business, I've found clamps work great
on stranded conductors, but on some devices, such as Leviton GFCI outlets,
the clamps are not nearly as secure with solid conductors

On 2/11/2009 4:27 AM RBM spake thus:

"Tom Horne" wrote in message
...

I do not know which clamps you are referring to but that does not
reconcile with my experience in thirty three years in the craft. The
screw tightened clamps I have encountered have been fine on both
stranded and solid conductors and work better on stranded wire then
any screw binding connection without clamps ever would.

And in my thirty seven years in the business, I've found clamps work
great on stranded conductors, but on some devices, such as Leviton
GFCI outlets, the clamps are not nearly as secure with solid
conductors

I've used those same outlets and have never experienced any problems
securing solid wire (#12 or #14) to the clamps. What specific problems
have you had?


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

On Feb 9, 11:24*pm, "RonABC" wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach more
than one wire to each screw. *I haven't been able to locate anything about
that in the 2008 National Electrical Code. *It may be in *there, but so far,
I haven't been able to find it.

Part of why I am curious is that I notice that typical outlet receptacles
have two silver screws, two gold screws, and only one green grounding screw.
And that started me wondering, "Why aren't there two green grounding
screws?" *For outlets that are in the middle of a circuit, there are
typically six wires in the outlet box -- two black, two white, and two
grounds. *So, wouldn't it be easier if the receptacle had 6 screws? -- two
for the two black wires, two for the two white wires, and two for the two
ground wires?

Is it possible that the code allows two ground wires to be connected to the
one green grounding screw, but does not permit two wires per screw for the
white and black wires?

If you use back-feed and one wire on the screw-you can utilize 3 wires
per screw. These are normally commercial or hospital grade 15 or
20Amp.

"David Nebenzahl" wrote in message
.com...
On 2/11/2009 4:27 AM RBM spake thus:

"Tom Horne" wrote in message
...

I do not know which clamps you are referring to but that does not
reconcile with my experience in thirty three years in the craft. The
screw tightened clamps I have encountered have been fine on both
stranded and solid conductors and work better on stranded wire then
any screw binding connection without clamps ever would.

And in my thirty seven years in the business, I've found clamps work
great on stranded conductors, but on some devices, such as Leviton
GFCI outlets, the clamps are not nearly as secure with solid
conductors

I've used those same outlets and have never experienced any problems
securing solid wire (#12 or #14) to the clamps. What specific problems
have you had?

The problem is, that after tightening, the wires come loose when pushing the
outlet back into the wall. They don't always come loose, but of the hundreds
of these things I've installed, too many do come loose. Conversely, of the
thousands of outlets I've installed with screw tight connectors, I've never
had one come loose


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

Tom Horne wrote:
On Feb 10, 9:29 am, "RonABC" wrote:

Also, if the wire that is cut off short leaves it with less than 6
inches of wire in the box, that would not meet the code requirements.

This last statement is untrue. The code requires six inches of wire
in the box and extending at least three inches beyond the opening of
the box "for splices or the connection of luminaires (fixtures) or
devices." The code does not require that the conductors be that long
after the splices are made up and the devices installed. Requiring
that would overcrowd many boxes and cause more problems.

Do you have to know where it says that in the code? I'd be interested in
looking that up and reading exactly what it says. Thanks.

Oops, I meant to write, "Do you *happen* to know where it says that in the
code?"

RonABC wrote:
Tom Horne wrote:
On Feb 10, 9:29 am, "RonABC" wrote:

Also, if the wire that is cut off short leaves it with less than 6
inches of wire in the box, that would not meet the code
requirements.

This last statement is untrue. The code requires six inches of wire
in the box and extending at least three inches beyond the opening of
the box "for splices or the connection of luminaires (fixtures) or
devices." The code does not require that the conductors be that long
after the splices are made up and the devices installed. Requiring
that would overcrowd many boxes and cause more problems.

Do you have to know where it says that in the code? I'd be
interested in looking that up and reading exactly what it says. Thanks.

RonABC wrote:
Oops, I meant to write, "Do you *happen* to know where it says that in the
code?"

RonABC wrote:
Tom Horne wrote:
On Feb 10, 9:29 am, "RonABC" wrote:

Also, if the wire that is cut off short leaves it with less than 6
inches of wire in the box, that would not meet the code
requirements.
This last statement is untrue. The code requires six inches of wire
in the box and extending at least three inches beyond the opening of
the box "for splices or the connection of luminaires (fixtures) or
devices." The code does not require that the conductors be that long
after the splices are made up and the devices installed. Requiring
that would overcrowd many boxes and cause more problems.
Do you have to know where it says that in the code? I'd be
interested in looking that up and reading exactly what it says. Thanks.



300.14

Tom Horne wrote:

This last statement is untrue. The code requires six inches of wire
in the box and extending at least three inches beyond the opening of
the box "for splices or the connection of luminaires (fixtures) or
devices." The code does not require that the conductors be that long
after the splices are made up and the devices installed.

I think you may be misreading what the code says and you are incorrectly
concluding that, after the splices are made, the length of conductor rule no
longer applies. The requirements are under 300.14, and then it says:

"Exception: Conductors that are *NOT* (emphasis added by me) spliced or
terminated at the outlet, junction, or switch point shall not be required to
comply with 300.14."

In other words, conductors that *ARE* spliced or terminated at the box do
have to comply with 300.14 even after they are spliced or terminated. Only
the unspliced or un-terminated-at-the-box conductors do not have to comply.

In article ,
David Nebenzahl wrote:

On 2/10/2009 5:37 AM Seth Goodman spake thus:

In article on Mon,
09 Feb 2009 22:47:38 -0800, David Nebenzahl wrote:

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.

By placing the receptacle in parallel with the circuit by pigtailing,
downstream outlets are unaffected by a problem with the receptacle, or
its outright removal.

But the only problem with the receptacle that could affect downstream
devices would be if the metal "bridge" between the two screws somehow
burned or melted out; pretty unlikely to happen. I still think this is a
perfectly good wiring method.

I'm with you on this. I see the pigtail system advocated frequently
here, and I think it's a lot of extra work for trivial if any gain. And,
I don't know where the pigtail people are finding all that room in a
typical old box to cram all that extra wire and wirenuts.

In article , "RBM"
wrote:

"David Nebenzahl" wrote in message
.com...
On 2/11/2009 4:27 AM RBM spake thus:

"Tom Horne" wrote in message
...

I do not know which clamps you are referring to but that does not
reconcile with my experience in thirty three years in the craft. The
screw tightened clamps I have encountered have been fine on both
stranded and solid conductors and work better on stranded wire then
any screw binding connection without clamps ever would.

And in my thirty seven years in the business, I've found clamps work
great on stranded conductors, but on some devices, such as Leviton
GFCI outlets, the clamps are not nearly as secure with solid
conductors

I've used those same outlets and have never experienced any problems
securing solid wire (#12 or #14) to the clamps. What specific problems
have you had?

The problem is, that after tightening, the wires come loose when pushing the
outlet back into the wall. They don't always come loose, but of the hundreds
of these things I've installed, too many do come loose. Conversely, of the
thousands of outlets I've installed with screw tight connectors, I've never
had one come loose


I used a few of those back clamp style at the g.f.'s house, and found I
had to torque the screws far beyond what I'd consider "reasonable and
customary" to keep the wires from breaking loose while folding them back
into the box. Went back to the side screws after that.

On Fri, 13 Feb 2009 06:07:44 -0800, Smitty Two
wrote:

In article ,
David Nebenzahl wrote:

On 2/10/2009 5:37 AM Seth Goodman spake thus:

In article on Mon,
09 Feb 2009 22:47:38 -0800, David Nebenzahl wrote:

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.

Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.

By placing the receptacle in parallel with the circuit by pigtailing,
downstream outlets are unaffected by a problem with the receptacle, or
its outright removal.

But the only problem with the receptacle that could affect downstream
devices would be if the metal "bridge" between the two screws somehow
burned or melted out; pretty unlikely to happen. I still think this is a
perfectly good wiring method.

I'm with you on this. I see the pigtail system advocated frequently
here, and I think it's a lot of extra work for trivial if any gain. And,
I don't know where the pigtail people are finding all that room in a
typical old box to cram all that extra wire and wirenuts.
Not to mention a wirenut connection is NOT as secure and easily
verified as a screw terminal connection. And the whole aluminun
pigtail to copper fiasco is even worse. Why would you add another
connection when CoALR devices are available???

In article , (Smitty Two) writes:
| In article , "RBM"
| wrote:

| The problem is, that after tightening, the wires come loose when pushing the
| outlet back into the wall. They don't always come loose, but of the hundreds
| of these things I've installed, too many do come loose. Conversely, of the
| thousands of outlets I've installed with screw tight connectors, I've never
| had one come loose
|
|
| I used a few of those back clamp style at the g.f.'s house, and found I
| had to torque the screws far beyond what I'd consider "reasonable and
| customary" to keep the wires from breaking loose while folding them back
| into the box. Went back to the side screws after that.

The problem I've seen is not that the wires come out but that they rotate
in place making me at least believe that they are not secure. This happens
with old wire that has obviously been bent many times before (perhaps work
hardened?). I find that there is a very narrow range of tightness between
when the wires stop rotating and when the screw strips. It is also mostly
a problem when only one wire is under the clamp, forcing it off-center and
allowing one side to bottom out. With two wires (i.e., one on each side of
the screw) things work better.

Dan Lanciani
ddl@danlan.*com

Smitty Two wrote:
In article ,
David Nebenzahl wrote:

On 2/10/2009 5:37 AM Seth Goodman spake thus:

In article on Mon,
09 Feb 2009 22:47:38 -0800, David Nebenzahl wrote:

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.
Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.
By placing the receptacle in parallel with the circuit by pigtailing,
downstream outlets are unaffected by a problem with the receptacle, or
its outright removal.
But the only problem with the receptacle that could affect downstream
devices would be if the metal "bridge" between the two screws somehow
burned or melted out; pretty unlikely to happen. I still think this is a
perfectly good wiring method.

I'm with you on this. I see the pigtail system advocated frequently
here, and I think it's a lot of extra work for trivial if any gain. And,
I don't know where the pigtail people are finding all that room in a
typical old box to cram all that extra wire and wirenuts.

it's actually easier to pigtail than to stuff an outlet back in with all
4 on IT.

I just did it both ways last night, and the pigtailing is far easier.


s

wrote:
On Fri, 13 Feb 2009 06:07:44 -0800, Smitty Two
wrote:

In article ,
David Nebenzahl wrote:

On 2/10/2009 5:37 AM Seth Goodman spake thus:

In article on Mon,
09 Feb 2009 22:47:38 -0800, David Nebenzahl wrote:

On 2/9/2009 10:12 PM Steve Barker spake thus:

the multiple cable outlet should be pigtailed out anyway. Only ONE
black, ONE white, and ONE bare go to the outlet. To daisy chain them
using the multiple screws is sloppy and asking for trouble.
Are you saying not to use both screws on a duplex outlet? I do this all
the time, and it seems perfectly safe and sensible, and saves a lot of
unnecessary pigtailing.

Unless I'm misunderstanding what you said.
By placing the receptacle in parallel with the circuit by pigtailing,
downstream outlets are unaffected by a problem with the receptacle, or
its outright removal.
But the only problem with the receptacle that could affect downstream
devices would be if the metal "bridge" between the two screws somehow
burned or melted out; pretty unlikely to happen. I still think this is a
perfectly good wiring method.
I'm with you on this. I see the pigtail system advocated frequently
here, and I think it's a lot of extra work for trivial if any gain. And,
I don't know where the pigtail people are finding all that room in a
typical old box to cram all that extra wire and wirenuts.
Not to mention a wirenut connection is NOT as secure and easily
verified as a screw terminal connection. And the whole aluminun
pigtail to copper fiasco is even worse. Why would you add another
connection when CoALR devices are available???

who said anythin about using aluminum ?

s

On Feb 12, 3:45*pm, "RonABC" wrote:
Tom Horne wrote:

This last statement is untrue. *The code requires six inches of wire
in the box and extending at least three inches beyond the opening of
the box "for splices or the connection of luminaires (fixtures) or
devices." *The code does not require that the conductors be that long
after the splices are made up and the devices installed.

I think you may be misreading what the code says and you are incorrectly
concluding that, after the splices are made, the length of conductor rule no
longer applies. *The requirements are under 300.14, and then it says:

"Exception: *Conductors that are *NOT* (emphasis added by me) spliced or
terminated at the outlet, junction, or switch point shall not be required to
comply with 300.14."

In other words, conductors that *ARE* spliced or terminated at the box do
have to comply with 300.14 even after they are spliced or terminated. *Only
the unspliced or un-terminated-at-the-box conductors do not have to comply.

Ron
I was not basing my position on the exception bout on the wording I
quoted in my reply. Two different boards of appeal that I know of
have come down in the same place. I know of no contrary formal
interpretation. I'll quote the whole section so that those without
ready access can follow the discussion.

"300.14 Length of Free Conductors at Outlets, Junctions, and Switch
Points.
At least 150 mm (6 in.) of free conductor, measured from the point in
the box where it emerges from its raceway or cable sheath, shall be
left at each outlet, junction, and switch point for splices or the
connection of luminaires (fixtures) or devices. Where the opening to
an outlet, junction, or switch point is less than 200 mm (8 in.) in
any dimension, each conductor shall be long enough to extend at least
75 mm (3 in.) outside the opening.

Exception: Conductors that are not spliced or terminated at the
outlet, junction, or switch point shall not be required to comply with
300.14."

My position, and the position of the Virginia state board of permit
appeals, is that the six inches of free conductors is required in
order to have enough wire to make the splices and connections during
make up and not forever afterward.

--
Tom Horne