To size a pull box:
Determine the size of the largest conduit for straight pulls and multiply that by 8. Horizontal and vertical straight pulls give us our box's minimum horizontal and vertical measurements, respectively.
Multiply the largest conduit for angle pulls by 6 and add the sizes of any other conduits in the same row as that conduit. Angle pulls from left/right, and top/bottom provide us with horizontal and vertical box measurements, respectively.
The largest measurements for vertical and horizontal measurements will be our box's recommended minimum dimensions.
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