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⚡ Code Corner: 🔸 NEC 314.28(A)(2) – Pull Box Sizing: Straight Pulls

Sharpen your knowledge with a quick dive into the NEC.

Author

Chris Martinez
June 10, 2025

📘 What NEC 314.28(A)(2) says:

What it says:
When conductors enter and exit a box in a straight line (same wall to opposite wall), the box must be at least 8 times the trade diameter of the largest conduit in the run.

Why it matters:
Undersized pull boxes make wire pulls brutal—and risky. NEC sizing ensures there's enough space for bending and pulling, reducing strain on conductors and minimizing insulation damage during installation.

💡 Pro Tip:
If you're running a 3" conduit straight through a pull box, the box must be at least 24 inches long in the direction of the pull. This is a minimum—larger is often better for future access.

❓ Quick Code Quiz: Chapter 3 – Pull and Junction Boxes

Choose the correct answer:

Question:
You’re installing a straight-through pull using 2" EMT. What’s the minimum length the pull box must be in the direction of the pull?

A) 12 inches
B) 16 inches
C) 8 inches
D) 10 inches

Answer below 👇

🧠 Think it through:
Multiply the largest trade size (2") by 8—because it's a straight pull, not an angle or U-pull.

✅ Answer: B) 16 inches

📘 Reference:
NEC 2023 – Article 314.28(A)(2): Boxes and Conduit Bodies – Sizing Pull and Junction Boxes

“Where splices or straight pulls are made, the length of the box shall not be less than 8 times the trade size of the largest raceway.”