Pull and Junction Box Sizing
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bphgravity
Senior Member
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- Florida
Re: Pull and Junction Box Sizing
As long as you meet the requirements specified in 314.28, volume calculations do not need to be made. This is figured into the respective formulas.
Table 314.16(A) does not go above #6 because you wouldn't be able to put anything larger than #6 in the particular boxes listed. If you are installing larger than #6 conductors, you will have to perform a box fill calcualtion and select a box with the minimum volume allowance.
As long as you meet the requirements specified in 314.28, volume calculations do not need to be made. This is figured into the respective formulas.
Table 314.16(A) does not go above #6 because you wouldn't be able to put anything larger than #6 in the particular boxes listed. If you are installing larger than #6 conductors, you will have to perform a box fill calcualtion and select a box with the minimum volume allowance.
ryan_618
Senior Member
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- Salt Lake City, Utah
Re: Pull and Junction Box Sizing
I would think that bending radius would become an issue before box fill would when dealing with 250's.
I would think that bending radius would become an issue before box fill would when dealing with 250's.
bphgravity
Senior Member
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- Florida
Re: Pull and Junction Box Sizing
Box fill calculations are really designed for boxes that are intended to be used as an outlet where a device or fixture will be mounted.
There are simply not many applications that would require larger than #6 branch-circuits that terminate into a box.
Above #6 are generally feeders and service conductors that may require pull boxes, j-boxes, and conduit bodies, but will terminate in large enclosures like panelboards and cabinets.
However, you may be able to determine a ratio using 314.16 to determine larger sized conductors. I have never run into this problem or had a need to do so.
Box fill calculations are really designed for boxes that are intended to be used as an outlet where a device or fixture will be mounted.
There are simply not many applications that would require larger than #6 branch-circuits that terminate into a box.
Above #6 are generally feeders and service conductors that may require pull boxes, j-boxes, and conduit bodies, but will terminate in large enclosures like panelboards and cabinets.
However, you may be able to determine a ratio using 314.16 to determine larger sized conductors. I have never run into this problem or had a need to do so.
Re: Pull and Junction Box Sizing
The Box Dimesionning is what you have to consider, allowing at all time the space for the bending radius of the conductor, The rule says that for straight pull Box Size should be At least 8 Times the Conduit Size, for Perpendicular Pull The Diagonal Dimension fron Conduit Center To Conduit Center is 6.5 Times Conduit Size, The Depth Of The Box Should Be Twice the size the largest conduit entering the box. Conduit Spacing One Conduit Size OC.
The Box Dimesionning is what you have to consider, allowing at all time the space for the bending radius of the conductor, The rule says that for straight pull Box Size should be At least 8 Times the Conduit Size, for Perpendicular Pull The Diagonal Dimension fron Conduit Center To Conduit Center is 6.5 Times Conduit Size, The Depth Of The Box Should Be Twice the size the largest conduit entering the box. Conduit Spacing One Conduit Size OC.
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