# How do you size a NEC pull box?

Category:
sports
walking

**Pull box sizing**is based on the

**size**and number of conductors, as well as the number of raceways and their diameter.

**Angle Pulls, U-Pulls and Splices**

- Six times the largest raceway diameter = 6 x 4” = 24”
- Sum of all other raceway diameters = 2” + 2” = 4”
- Total = 24” + 4” = 28”

Beside this, how do I know what size electrical pull box I need?

**How to Calculate Underground Pull Box Sizing**

- Largest Raceway Size x 8 = Minimum Box Length. For example, if your raceway is 3'': 3'' x 8 = 24''
- (Largest Raceway Size x 6) + Sizes of Raceways on the Same Row. = Minimum Box Length.
- Largest Raceway Size x 6 = Minimum Distance Between Raceways. For example, if you have a 3'' raceway from left to bottom:

**3 inches**) multiplied by eight. The length of this pull box must be at least

**24 inches**(see Figure 7).

Also asked, how do you size an electrical trough?

Look up the area of each conductor **size** in the tables, multiply by the number of conductors, add them for a total, multiply by 5 (5 x 20% fill) and then you have the minimum cross sectional area of your wireway.

does anyone know if its in the code book where you need a **pull box** every 100 **feet**? You can go as **many feet** as you want.. the code only restricts the number of bends **between boxes** or fittings like a LB to (360) degrees..