# sizing junction boxes for 4awg and larger



## william1978 (Sep 21, 2008)

..........................


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## electricalperson (Jan 11, 2008)

i was going from the left side it had a 3 inch conduit and a 2 inch

once you figure the horizontal using the conduits on the left side you cant use that side to figure the vertical dimension? you have to use the 3 inch on the bottom?

i was confused because the code says 6 times the size of the largest raceway plus the sum of the other raceways in the same row. so 6 x 3 + 2 = 20 but in the example mike holt is doing 6 x 3 = 18 without adding the 2 inch

the 2 and 3 inch are grayed out on the left side. im taking it once you figure the horizontal and use the conduit in a calculation you cant use it for any other calculation? the way i understand the code it says the largest calculation must be used.


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## william1978 (Sep 21, 2008)

electricalperson said:


> i was going from the left side it had a 3 inch conduit and a 2 inch
> 
> once you figure the horizontal using the conduits on the left side you cant use that side to figure the vertical dimension? you have to use the 3 inch on the bottom?
> 
> ...


 Your right 20x20 is correct. Man it is time for bed magor brain fart.


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## electricalperson (Jan 11, 2008)

i must be ********.

its measured to the OPPOSITE wall!

the conduits on the left are not OPPOSITE of the wall on the bottom. 

6 x 3 is the measurement from the conduit on the TOP to the OPPOSITE WALL for the vertical dimension

i had a brain fart.


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## electricalperson (Jan 11, 2008)

the box is 20 x 18. 

20 is the horizontal measurement 

6x3+2 = 20

the 2 x 8 measurement is not used because its smaller than the angle pull calculation.

the vertical measurement is 6 x 3. there is a single 3 inch conduit on the top. 

6 x 3 = 18

i got confused but im ok now


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## william1978 (Sep 21, 2008)

electricalperson said:


> i must be ********.
> 
> its measured to the OPPOSITE wall!
> 
> ...


 I am confused now. I wonder if there is any way you could post the question in the book? Does it have a pic with it?


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## electricalperson (Jan 11, 2008)

william1978 said:


> I am confused now. I wonder if there is any way you could post the question in the book? Does it have a pic with it?


here is exactly what it says in the book

a pull box contains a trade size 2 and a trade size 3 raceway on the left side, a trade size 3 raceway on the top and a trade size 2 raceway on the right side. the trade size 2 raceway is a straight pull and the trade size 3 raceway are an angle pull.

the horizontal measurement is 

8x2 = 16 NOT USED
6 x 3 + 2 = 20 USED

the vertical measurement is 
6 x 3 = 18 

the box is 20 x 18

the code articles are 314.28A2


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## william1978 (Sep 21, 2008)

electricalperson said:


> the box is 20 x 18
> 
> the code articles are 314.28A2


 That is the answer that would be on the test,but we all know we would be buying a 20x20.:thumbsup: It looks like you got it.


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## electricalperson (Jan 11, 2008)

even bigger would be better. im studying for my massachusetts masters test


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## william1978 (Sep 21, 2008)

electricalperson said:


> even bigger would be better. im studying for my massachusetts masters test


 You got that right. Good luck on the test.:thumbsup:


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## electricalperson (Jan 11, 2008)

thanks


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