Do I have this right?

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds 1
Oulet 3

Total 10
10 times 2.25 = 22.5 cubic inch box needed.

On 2010-03-15, Limp Arbor wrote:

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds 1
Oulet 3

Devices are 2 per strap. So for a single gang duplex receptacle,
that's just 2.

Total 10

Total 9, as long as you don't have any cable clamps that extend into
the box.

10 times 2.25 = 22.5 cubic inch box needed.

9 * 2.25 = 20.25

Cheers, Wayne

"Limp Arbor" wrote in message
...
Do I have this right?

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds 1
Oulet 3

Total 10
10 times 2.25 = 22.5 cubic inch box needed.


Wayne gave you the math. Personally I just read the numbers printed on the
boxes. For the last 20 years or more they tell you right on the box how
many and what size wire. Actually I think it is stamped inside the box.

Pigtails that start and end in the box do not count.

I recall from memory that a standard switch box can only handle 2-3 wire
cables. I think the deeper box can handle 3.


--
Colbyt
Please come visit http://www.househomerepair.com

On Mar 15, 11:57*am, "Colbyt" wrote:
"Limp Arbor" wrote in message

...

Do I have this right?

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds * *1
Oulet * * *3

Total * * 10
10 times 2.25 = 22.5 cubic inch box needed.

Wayne gave you the math. *Personally I just read the numbers printed on the
boxes. *For the last 20 years or more they tell you right on the box how
many and what size wire. Actually I think it is stamped inside the box.

Pigtails that start and end in the box do not count.

I recall from memory that a standard switch box can only handle 2-3 wire
cables. *I think the deeper box can handle 3.

if by "standard" you mean a 2-1/2" deep box, if you have a device in
it, you can only use *one* cable.

What this means to me is, I need to replace a lot of boxes in my
house, because I am repulling a lot of stuff, and those boxes that met
code when they were installed now no longer do.

nate

"N8N" wrote in message
...
On Mar 15, 11:57 am, "Colbyt" wrote:
"Limp Arbor" wrote in message

...

Do I have this right?

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds 1
Oulet 3

Total 10
10 times 2.25 = 22.5 cubic inch box needed.

Wayne gave you the math. Personally I just read the numbers printed on the
boxes. For the last 20 years or more they tell you right on the box how
many and what size wire. Actually I think it is stamped inside the box.

Pigtails that start and end in the box do not count.

I recall from memory that a standard switch box can only handle 2-3 wire
cables. I think the deeper box can handle 3.

if by "standard" you mean a 2-1/2" deep box, if you have a device in
it, you can only use *one* cable.

What this means to me is, I need to replace a lot of boxes in my
house, because I am repulling a lot of stuff, and those boxes that met
code when they were installed now no longer do.

nate

Not sure where you are getting this information. Perhaps your local codes
are different. Maybe something changed in the last 12 months.

I had a fully inspected, both rough and final about 12 months ago. Devices
did not enter into the equation. Two #12 cables per standard switch box,
just like the numbers printed on the box. Three permitted in the deeper box.
These are the plastic/composite boxes.

There is no requirement to upgrade anything unless you pull new wire to a
box, then you need to do so. Yes there are a lot of old metal boxes that do
not meet what I believe to be the current code.

Colbyt

On Mar 15, 11:43*am, Wayne Whitney wrote:
On 2010-03-15, Limp Arbor wrote:

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds * *1
Oulet * * *3

Devices are 2 per strap. *So for a single gang duplex receptacle,
that's just 2.

Total * * 10

Total 9, as long as you don't have any cable clamps that extend into
the box.

10 times 2.25 = 22.5 cubic inch box needed.

9 * 2.25 = 20.25

Cheers, Wayne

Thanks Wayne. I read 2 and knew it was 2 but don't know why I wrote 3
for the outlet.

So a dimmer switch or a GFCI outlet count the same as a single pole
switch?

It also sounds like you don't have to count wire nuts or pigtails.

I found the table online he
http://ftp.resource.org/bsc.ca.gov/t...3_page0219.pdf

On Mar 15, 1:04*pm, "Colbyt" wrote:
"N8N" wrote in message

...
On Mar 15, 11:57 am, "Colbyt" wrote:





"Limp Arbor" wrote in message

....

Do I have this right?

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds 1
Oulet 3

Total 10
10 times 2.25 = 22.5 cubic inch box needed.

Wayne gave you the math. Personally I just read the numbers printed on the
boxes. For the last 20 years or more they tell you right on the box how
many and what size wire. Actually I think it is stamped inside the box.

Pigtails that start and end in the box do not count.

I recall from memory that a standard switch box can only handle 2-3 wire
cables. I think the deeper box can handle 3.

if by "standard" you mean a 2-1/2" deep box, if you have a device in
it, you can only use *one* cable.

What this means to me is, I need to replace a lot of boxes in my
house, because I am repulling a lot of stuff, and those boxes that met
code when they were installed now no longer do.

nate

Not sure where you are getting this information. *Perhaps your local codes
are different. *Maybe something changed in the last 12 months.

I had a fully inspected, both rough and final about 12 months ago. *Devices
did not enter into the equation. *Two #12 cables per standard switch box,
just like the numbers printed on the box. Three permitted in the deeper box.
These are the plastic/composite boxes.

http://www.selfhelpandmore.com/home-...tions-2002.php

The Chart Mentioned Says That (NEC Article 314.16.B):

14 Awg. = 2 Cu. In. per conductor,
12 Awg. = 2.25 Cu. In. per conductor
10 Awg. = 2.5 Cu. In. per conductor
8 Awg. = 3 Cu. In. per conductor
6 Awg. = 5 Cu. In. per current carrying conductor counted.

are you counting two conductors for the device yoke, one for the
clamps, and one for the ground? A 14/2 WG (3 "conductors",) clamp
(1,) and receptacle (2,) requires 12 in^3; another cable would bump
that up to 16 in^3. (add 2 "conductors" for the 14/2, ground still is
only counted once.) If I were using 12/2WG then that would be 13.5
and 18 in^3 respectively.

http://www.hubbellonline.com/wiring/...ll/pdf/a43.pdf

per the above sheet, a 2-1/2" deep Raco metal switch box is 12.5 in^3


There is no requirement to upgrade anything unless you pull new wire to a
box, then you need to do so. Yes there are a lot of old metal boxes that do
not meet what I believe to be the current code.

Right, that's the issue, I have 2-1/2" switch boxes being used in the
middle of a run (e.g. 2x 14/2 romex *without* ground in each box,
except at the end of a run) if I replace the old cable with 14/2WG
then technically that whole box needs to meet current code, so I have
to bust it out and replace it with a deeper box.

nate

Do I have this right?

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds 1
Oulet 3

Total 10
10 times 2.25 = 22.5 cubic inch box needed.

Wayne gave you the math. Personally I just read the numbers printed on
the
boxes. For the last 20 years or more they tell you right on the box how
many and what size wire. Actually I think it is stamped inside the box.

Pigtails that start and end in the box do not count.

I recall from memory that a standard switch box can only handle 2-3 wire
cables. I think the deeper box can handle 3.

if by "standard" you mean a 2-1/2" deep box, if you have a device in
it, you can only use *one* cable.

What this means to me is, I need to replace a lot of boxes in my
house, because I am repulling a lot of stuff, and those boxes that met
code when they were installed now no longer do.

nate

Not sure where you are getting this information. Perhaps your local codes
are different. Maybe something changed in the last 12 months.

I had a fully inspected, both rough and final about 12 months ago. Devices
did not enter into the equation. Two #12 cables per standard switch box,
just like the numbers printed on the box. Three permitted in the deeper
box.
These are the plastic/composite boxes.

http://www.selfhelpandmore.com/home-...tions-2002.php

The Chart Mentioned Says That (NEC Article 314.16.B):

14 Awg. = 2 Cu. In. per conductor,
12 Awg. = 2.25 Cu. In. per conductor
10 Awg. = 2.5 Cu. In. per conductor
8 Awg. = 3 Cu. In. per conductor
6 Awg. = 5 Cu. In. per current carrying conductor counted.

are you counting two conductors for the device yoke, one for the
clamps, and one for the ground? A 14/2 WG (3 "conductors",) clamp
(1,) and receptacle (2,) requires 12 in^3; another cable would bump
that up to 16 in^3. (add 2 "conductors" for the 14/2, ground still is
only counted once.) If I were using 12/2WG then that would be 13.5
and 18 in^3 respectively.

http://www.hubbellonline.com/wiring/...ll/pdf/a43.pdf

per the above sheet, a 2-1/2" deep Raco metal switch box is 12.5 in^3


There is no requirement to upgrade anything unless you pull new wire to a
box, then you need to do so. Yes there are a lot of old metal boxes that
do
not meet what I believe to be the current code.

Right, that's the issue, I have 2-1/2" switch boxes being used in the
middle of a run (e.g. 2x 14/2 romex *without* ground in each box,
except at the end of a run) if I replace the old cable with 14/2WG
then technically that whole box needs to meet current code, so I have
to bust it out and replace it with a deeper box.



*If you have just drywall for your finished wall you can probably pry the
old 2.5" box out without too much damage to the wall. To replace it you
could take a 3.5" gem box, drill a hole in the side and stick it in the same
wall opening. Mount it with some Madison bars and shoot one screw through
the hole. The other choice is to install a plastic old work box which will
require a bigger opening in the wall. For more info:
http://www.mrelectrician.tv/question...OutletBox.html

On 03/15/2010 04:29 PM, John Grabowski wrote:
Do I have this right?

Three 12/2 NM cables going into a plastic box with an outlet

conductors 6
grounds 1
Oulet 3

Total 10
10 times 2.25 = 22.5 cubic inch box needed.

Wayne gave you the math. Personally I just read the numbers printed
on the
boxes. For the last 20 years or more they tell you right on the box how
many and what size wire. Actually I think it is stamped inside the box.

Pigtails that start and end in the box do not count.

I recall from memory that a standard switch box can only handle 2-3
wire
cables. I think the deeper box can handle 3.

if by "standard" you mean a 2-1/2" deep box, if you have a device in
it, you can only use *one* cable.

What this means to me is, I need to replace a lot of boxes in my
house, because I am repulling a lot of stuff, and those boxes that met
code when they were installed now no longer do.

nate

Not sure where you are getting this information. Perhaps your local codes
are different. Maybe something changed in the last 12 months.

I had a fully inspected, both rough and final about 12 months ago.
Devices
did not enter into the equation. Two #12 cables per standard switch box,
just like the numbers printed on the box. Three permitted in the
deeper box.
These are the plastic/composite boxes.

http://www.selfhelpandmore.com/home-...tions-2002.php


The Chart Mentioned Says That (NEC Article 314.16.B):

14 Awg. = 2 Cu. In. per conductor,
12 Awg. = 2.25 Cu. In. per conductor
10 Awg. = 2.5 Cu. In. per conductor
8 Awg. = 3 Cu. In. per conductor
6 Awg. = 5 Cu. In. per current carrying conductor counted.

are you counting two conductors for the device yoke, one for the
clamps, and one for the ground? A 14/2 WG (3 "conductors",) clamp
(1,) and receptacle (2,) requires 12 in^3; another cable would bump
that up to 16 in^3. (add 2 "conductors" for the 14/2, ground still is
only counted once.) If I were using 12/2WG then that would be 13.5
and 18 in^3 respectively.

http://www.hubbellonline.com/wiring/...ll/pdf/a43.pdf

per the above sheet, a 2-1/2" deep Raco metal switch box is 12.5 in^3


There is no requirement to upgrade anything unless you pull new wire to a
box, then you need to do so. Yes there are a lot of old metal boxes
that do
not meet what I believe to be the current code.

Right, that's the issue, I have 2-1/2" switch boxes being used in the
middle of a run (e.g. 2x 14/2 romex *without* ground in each box,
except at the end of a run) if I replace the old cable with 14/2WG
then technically that whole box needs to meet current code, so I have
to bust it out and replace it with a deeper box.



*If you have just drywall for your finished wall you can probably pry
the old 2.5" box out without too much damage to the wall. To replace it
you could take a 3.5" gem box, drill a hole in the side and stick it in
the same wall opening. Mount it with some Madison bars and shoot one
screw through the hole. The other choice is to install a plastic old
work box which will require a bigger opening in the wall. For more info:
http://www.mrelectrician.tv/question...OutletBox.html


The walls are plaster, but that is what I plan to do. I have already
done this with several boxes for other reasons (loose boxes in two
instances; another instance I was trying to replace a 2-wire cable with
a 3-wire cable so I could have a 3-way switch for the light at teh
bottom of the basement stairs, and I couldn't fish the cable without
removing the box) so I have the technique down. It just looks like to
pass my inspection I need to R&R *every* recep box in the area in which
I'm upgrading unless it is at the end of a circuit, whether I need to do
so to fish the cables or not. C'est la vie, I was just posting to
explain what my (and my local inspector's) interpretation of recent box
fill codes was, and why I said that a switch box could only have one cable.

Per the above, it appears that even a 14/3WG switch leg (e.g. for a
ceiling fan/ light control in a single gang box) requires a 14 in^3 box;
that is possible with a single gang 2.5" deep box, but not the kind with
the beveled corners, it has to be a squared-off one. (2x3x2.5 = 15 in^3)

nate

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