Connecting only one wire per device in a box.

[gore]

Does the NEC say that you can only connect one set of wires per device in a
box? The reason I ask is because I was working with an electrician and he
had me pigtail every connection where we fed multiple outlets with one feed.
Here's what I don't understand about that. If I am running a feed to a
pigtail which is made using either wire nuts, or those push in three hole
connectors, how is that a more "failsafe" connection than using the screws
on the sides (top and bottom) of the outlet? I have seen times where a
wirenut has fallen off of a connection (I assume from vibrations caused from
walking or jumping around) and the push in connectors, although very quick
to use, seem to work similar to the push in feature in the back of outlets
which I was told from a teacher never to use because they only make contact
with a small area of the conductor and that isn't as solid of a connection.
Would someone clarify this for for me? I wired my house using the top and
bottom of the outlet and just pigtailing the ground, but now I am thinking I
might have to go through and add pigtails to the hot and neutral too.

Thanks

 

[Anthony]

Does the NEC say that you can only connect one set of wires per device
in a box? The reason I ask is because I was working with an
electrician and he had me pigtail every connection where we fed
multiple outlets with one feed. Here's what I don't understand about
that. If I am running a feed to a pigtail which is made using either
wire nuts, or those push in three hole connectors, how is that a more
"failsafe" connection than using the screws on the sides (top and
bottom) of the outlet? I have seen times where a wirenut has fallen
off of a connection (I assume from vibrations caused from walking or
jumping around) and the push in connectors, although very quick to
use, seem to work similar to the push in feature in the back of
outlets which I was told from a teacher never to use because they only
make contact with a small area of the conductor and that isn't as
solid of a connection. Would someone clarify this for for me? I wired
my house using the top and bottom of the outlet and just pigtailing
the ground, but now I am thinking I might have to go through and add
pigtails to the hot and neutral too.

Thanks

From my understanding:
A typical garden-variety duplex receptical is generally rated for 15A,
while your branch receptical circuit is normally over-current protected
at 20A. If you wire to the screws or push-in terminals, you potentially
limit your current carrying capacity to 15A total for the remainder of
the circuit (including the load on the first receptical) and the first
receptical in the string could potentially become the "fuse" for the
circuit.
I have _always_ pig-tailed receptical circuits. It takes a bit more time,
but the peace of mind is worth it imho.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

 

[ehsjr]

Does the NEC say that you can only connect one set of wires per device in a
box? The reason I ask is because I was working with an electrician and he
had me pigtail every connection where we fed multiple outlets with one feed.
Here's what I don't understand about that. If I am running a feed to a
pigtail which is made using either wire nuts, or those push in three hole
connectors, how is that a more "failsafe" connection than using the screws
on the sides (top and bottom) of the outlet? I have seen times where a
wirenut has fallen off of a connection (I assume from vibrations caused from
walking or jumping around) and the push in connectors, although very quick
to use, seem to work similar to the push in feature in the back of outlets
which I was told from a teacher never to use because they only make contact
with a small area of the conductor and that isn't as solid of a connection.
Would someone clarify this for for me? I wired my house using the top and
bottom of the outlet and just pigtailing the ground, but now I am thinking I
might have to go through and add pigtails to the hot and neutral too.

Thanks

With pigtailing throughout, you can pull a receptacle
without disturbing the rest of the circuit. It's a
higher quality job. If you did not pigtail, but did
things right at the time you did the installatiom, you
have nothing to worry about.

Don't use those )*&%$! backstabs. They may be solid when
initially installed, but over time the metal contacts lose
tension and the once reliable connection becomes a problem.

Regarding wirenuts - in a properly done wirenut connection,
the wirenut will not fall off.

Ed

 

[gore]

Does the NEC say that you can only connect one set of wires per device in
a box? The reason I ask is because I was working with an electrician and
he had me pigtail every connection where we fed multiple outlets with one
feed. Here's what I don't understand about that. If I am running a feed to
a pigtail which is made using either wire nuts, or those push in three
hole connectors, how is that a more "failsafe" connection than using the
screws on the sides (top and bottom) of the outlet? I have seen times
where a wirenut has fallen off of a connection (I assume from vibrations
caused from walking or jumping around) and the push in connectors,
although very quick to use, seem to work similar to the push in feature in
the back of outlets which I was told from a teacher never to use because
they only make contact with a small area of the conductor and that isn't
as solid of a connection. Would someone clarify this for for me? I wired
my house using the top and bottom of the outlet and just pigtailing the
ground, but now I am thinking I might have to go through and add pigtails
to the hot and neutral too.

Thanks

Thanks for the responses. I did use the top and bottom screws when I wired
my house, but I can see the advantage to pigtailing now. If for some reason
I might have to change an outlet it would be faster to loosen and hook up 3
connections than 5 the way I have it now. Anthony made me think a little
about the 15 amp fuse thing though which makes me want to ask another
question. I read one of the posts either in this group or in alt.home.repair
that the breakers were to protect the wire more so than the device connected
to the wire. If this is the case is the metal connecting the 2 screws of a
15 amp outlet actually designed to open if a load greater than 15 amps is
drawn? Not trying to be an idiot here, but I took only a 10 week course in
electricity and am finding that there is a lot more to learn. The
pigtailing thin only came up in the course after we had used all of the
screws on an outlet and need to feed more devices on the circuit.

 

[Bud--]

However, pigtailing will require larger boxes to meet
code. Remember, 2 cubic inches are required for each No. 14 AWG and
2.25 cubic inches is required for each No. 12 AWG. Counting these the
number of wires can be difficult but here are the rules:

Please explain how, when pigtailing, the US-NEC requires a larger box.

I agree with ehsjr on backstabs. I have seen a lot of other posts not to
use them and no posts recommending their use.

I also agree with ehsjr that properly applied wirenuts are very reliable
and won't fall off.

A 15A duplex receptacle is rated for 20A pass through (screw-to-screw)
and 20A total current from the 2 receptacles.

With some exceptions, like motors, circuit breakers protect the wire and
the equipment connected. Equipment sometimes has an internal line fuse,
but more often not.

On multiwire circuits (hots from both legs and a neutral) the neutral is
required to be pigtailed. That prevents the neutral from being
disconnected for the downstream circuit (a real bad idea) if the
receptacle is replaced with the circuits hot.

 

[[email protected]]

| A typical garden-variety duplex receptical is generally rated for 15A,

Even if the configuration of the holes in front designate it to accept
only a "15A style plug", these are supposed to be rated at 20A total
for a UL listing. Perhaps the actual contacts in half of a duplex may
not handle more than 15A, but the whole thing has to handle 20A.

 

[[email protected]]

| Regarding wirenuts - in a properly done wirenut connection,
| the wirenut will not fall off.

Maybe it's because they were not done properly. But every failed
connection I've ever encountered has been a wirenut splice or pigtail
that, while staying together, ended up overheating due to a poor
electrical connection. I've never encountered such a failure for
screw on terminals at the devices. Personally, I would prefer that
the circuit go _through_ the device rather than around it where a
pigtail is required. For a basic 2-wire circuit, that's easy to do.
For a shared neutral it's not unless the device can be wired across
both poles of the circuit and has the 6 screws needed for in and out
on all 3 wires of a 3-wire shared neutral circuit. OTOH, I intend
to have no shared neutral circuits supplying multiple devices.

 

[[email protected]]

| Thanks for the responses. I did use the top and bottom screws when I wired
| my house, but I can see the advantage to pigtailing now. If for some reason
| I might have to change an outlet it would be faster to loosen and hook up 3
| connections than 5 the way I have it now. Anthony made me think a little
| about the 15 amp fuse thing though which makes me want to ask another
| question. I read one of the posts either in this group or in alt.home.repair
| that the breakers were to protect the wire more so than the device connected
| to the wire. If this is the case is the metal connecting the 2 screws of a
| 15 amp outlet actually designed to open if a load greater than 15 amps is
| drawn? Not trying to be an idiot here, but I took only a 10 week course in
| electricity and am finding that there is a lot more to learn. The
| pigtailing thin only came up in the course after we had used all of the
| screws on an outlet and need to feed more devices on the circuit.

What looks like a 15A device is really a 20A capacity device, with only the
possible exception of 15A maximum per individual outlet (half of a duplex).
To get the rating it must handle 20A total in any combination of usage by
either of the 2 outlets or the next downstream connection(s). In many cases
the internal conductor construction of what is a NEMA 5-15R device is the
same as a NEMA 5-20R device but with the openings cut different in the face.

 

[Ben Miller]

From my understanding:
A typical garden-variety duplex receptical is generally rated for 15A,
while your branch receptical circuit is normally over-current protected
at 20A. If you wire to the screws or push-in terminals, you potentially
limit your current carrying capacity to 15A total for the remainder of
the circuit (including the load on the first receptical) and the first
receptical in the string could potentially become the "fuse" for the
circuit.

Not true. 15A receptacles will carry 20A just fine. They are the same
receptacle except for the slot configuration on the front.

Ben Miller

 

[Ben Miller]

Does the NEC say that you can only connect one set of wires per device in
a box? The reason I ask is because I was working with an electrician and
he had me pigtail every connection where we fed multiple outlets with one
feed. Here's what I don't understand about that. If I am running a feed to
a pigtail which is made using either wire nuts, or those push in three
hole connectors, how is that a more "failsafe" connection than using the
screws on the sides (top and bottom) of the outlet? I have seen times
where a wirenut has fallen off of a connection (I assume from vibrations
caused from walking or jumping around) and the push in connectors,
although very quick to use, seem to work similar to the push in feature in
the back of outlets which I was told from a teacher never to use because
they only make contact with a small area of the conductor and that isn't
as solid of a connection. Would someone clarify this for for me? I wired
my house using the top and bottom of the outlet and just pigtailing the
ground, but now I am thinking I might have to go through and add pigtails
to the hot and neutral too.

Thanks

If the receptacle is listed and designed for two wires, then it is perfectly
acceptable to install them. This applies to multiple rear entry or side
entry holes, or screws that have a clamping plate. You can not install two
wires into a single hole, or wrap two wires around the screw itself.


Ben Miller
[/QUOTE]

 

[gore]

Does the NEC say that you can only connect one set of wires per device in
a box? The reason I ask is because I was working with an electrician and
he had me pigtail every connection where we fed multiple outlets with one
feed. Here's what I don't understand about that. If I am running a feed to
a pigtail which is made using either wire nuts, or those push in three
hole connectors, how is that a more "failsafe" connection than using the
screws on the sides (top and bottom) of the outlet? I have seen times
where a wirenut has fallen off of a connection (I assume from vibrations
caused from walking or jumping around) and the push in connectors,
although very quick to use, seem to work similar to the push in feature in
the back of outlets which I was told from a teacher never to use because
they only make contact with a small area of the conductor and that isn't
as solid of a connection. Would someone clarify this for for me? I wired
my house using the top and bottom of the outlet and just pigtailing the
ground, but now I am thinking I might have to go through and add pigtails
to the hot and neutral too.

Thanks

Thankyou all for your help.

 

[John Gilmer]

You got me bud,
I made an error. It is not a code issue, but sometimes the additional
wire and wire nuts can make it difficult to stuff the box.

Well, about a year ago I picked up some wirenuts with a built in flexible
wire pigtail.

I used a few of them. The advantage is that you pack in the solid wire and
the wirenuts and you have the flexible wires to connect to the outlet. If
you wire through the outlet you end up stuffing an outlet back into the box
with 5 solid wires attached.

 

[Paul Hovnanian P.E.]

Well, about a year ago I picked up some wirenuts with a built in flexible
wire pigtail.

I used a few of them. The advantage is that you pack in the solid wire and
the wirenuts and you have the flexible wires to connect to the outlet. If
you wire through the outlet you end up stuffing an outlet back into the box
with 5 solid wires attached.

Somebody needs to develop a hydraulic press to get these devices into
boxes.

;-)

 

[John Gilmer]

Somebody needs to develop a hydraulic press to get these devices into
boxes.

Well, "they" make a gadget that plugs into a duplex outlet that helps guide
it into place.It's on the list of things I always wish I had but never buy before the
need.