Minimum box depth for a receptacle

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I realize now that a box fill calculation requires an 18 cubic inch box if I have a #12 AC cable in and #12 AC out to the next duplex.

However, I am still wondering if a 1.5" deep double gang box would work?
 
steve66 said:
I realize now that a box fill calculation requires an 18 cubic inch box if I have a #12 AC cable in and #12 AC out to the next duplex.

However, I am still wondering if a 1.5" deep double gang box would work?


A box with one AC cable in, one out and with one device, would require a box with 13.5 CU inches.


2.25(6)=13.5
 
infinity said:
steve66 said:
I realize now that a box fill calculation requires an 18 cubic inch box if I have a #12 AC cable in and #12 AC out to the next duplex.

However, I am still wondering if a 1.5" deep double gang box would work?


A box with one AC cable in, one out and with one device, would require a box with 13.5 CU inches.


2.25(6)=13.5
I count 7
 
If you go 2-gang with a ring, don't forget that the ring buys you some volume too...
 
Jim W in Tampa said:
iwire said:
Jim W in Tampa said:
I count 7

Is that 'New Math'? :lol:
All the AC we buy has a green ground

Two possibilities

Your buying MC, it has plastic wrap under the armor, no paper.

Your buying Hospital grade AC which has a paper wrap and a small aluminum bonding strip.

If its Hospital AC and your using it for everything you might as well throw money in ocean.
 
AC cable does not have an equipment grounding conductor.
AC has a paper wrap with an aluminum bonding strip
MC has an insulated equipment grounding conductor

Its "paper or plastic"
 
tom baker said:
AC cable does not have an equipment grounding conductor.
AC has a paper wrap with an aluminum bonding strip
MC has an insulated equipment grounding conductor

Its "paper or plastic"


Tom,
"The times they are a-changin"

There is AC cable with an equipment ground conductor - HFC & the plain version available.

There is MC cable without an equipment ground and a 10 AWG aluminum bond strip, and it is listed. The sheath qualifies as an equipment ground.
Available is sizes 14, 12, 10
 
Jim W in Tampa said:
infinity said:
steve66 said:
I realize now that a box fill calculation requires an 18 cubic inch box if I have a #12 AC cable in and #12 AC out to the next duplex.

However, I am still wondering if a 1.5" deep double gang box would work?


A box with one AC cable in, one out and with one device, would require a box with 13.5 CU inches.


2.25(6)=13.5
I count 7

Ok so you have 7. Still doesn't add up to 18. 2.25(7)=15.75
 
I got 18 cu inch from:

1 for ground wire
4 for 2 neutral wires and 2 hots landing on the recept.
2 for the device
1 for two AC clamps

which gave 18 cu inches from the 99 code. See about half way down on this link:

http://www.hubbellcatalog.com/raco/RACO_boxes.asp?FAM=RacoBoxes

But on the box fill table, #12 has a (2.25) behind it. Does that mean 2.25" is the minimum depth for a box with #12 wire in it?? (#18 has a 1.5 behind it.)

And why do they call the boxes "switch" boxes?

Steve
 
2.25 is the cubic inches required for a 12 AWG.

If you had a box not listed you would use the 2.25 inch to figure your fill.

A 12" x 12" x 6" J-box has a volume of 564 cu in.

It can contain 384 - 12 AWGs
 
steve66

counting 1 for two ac cable clamps... are those clamps built into the box?

or did you buy them seperately and install them in a knockout?
 
Jim W in Tampa said:
iwire said:
2.25 is the cubic inches required for a 12 AWG.

If you had a box not listed you would use the 2.25 inch to figure your fill.

A 12" x 12" x 6" J-box has a volume of 564 cu in.

It can contain 384 - 12 AWGs

New math BOB ?

:lol: :oops:

Good catch Jim.

Not new math....bad fingers. :roll:

Should have been 864 cu in.

Spell check should also check my math... :p
 
Re: Minimum box depth for a receptacle

steve66 said:
Can you mount a receptacle in a 1.5" deep box?
314.24 Depth of Outlet Boxes. No box shall have an internal depth of less than 12.7 mm ( 1 /2 in.). Boxes intended to enclose flush devices shall have an internal depth of not less than 23.8 mm ( 15 /16 in.).
Ha ha, I beat everybody and I'm a day late! What do I win? :twisted:

sc_1_s_lxmow_0_ld.gif

I pulled a box out of a homeowner basement finish a while back that was barely 15/16" deep, it was this style. The reason this box was used was because they built the walls with 1x4's nailed to the basement wall, and then paneling over that. The romex entered a (unprotected) knockout, and went straight into the receptacle. To say the least, it was a tight fit. :shock: :eek:
 
Re: Minimum box depth for a receptacle

georgestolz said:
steve66 said:
Can you mount a receptacle in a 1.5" deep box?
314.24 Depth of Outlet Boxes. No box shall have an internal depth of less than 12.7 mm ( 1 /2 in.). Boxes intended to enclose flush devices shall have an internal depth of not less than 23.8 mm ( 15 /16 in.).
Ha ha, I beat everybody and I'm a day late! What do I win? :twisted:

Nothing! Absolutely nothing! :lol:

If you have a 15/16 device box you may well be able to mount a receptacle in it.

You will not be able to wire it, box fill limitations prevent it.

A 15/16" deep device box would be required to have it's volume marked but we can figure it roughly as 2 x 3 x .9375 = 5.625 cu. in.

With one 14/2 NM and external clamps

Hot, 2 cu in

Neutral, 2 cu in

Ground, 2 cu in

Device, 4 cu in.

Looks like 10 cu in is the bare minimum.

Now if you used a shallow 4" sq with a single gang ring you could do that.
 
What gets me is these boxes are produced and sold on the open market and the can`t legally be used due to code compliance for power anyway.The big O has boxes of these and those small blue bracket boxes and they also are to small to be used.
 
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