# How do you size a NEC pull box?

**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:

Secondly, what is the minimum length of the pull box? The minimum length of this box is the trade size of the largest raceway (**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.

How many feet are between pull boxes?

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..