You are designing a horizontal pathway system where you will provide 100 mm (4 in) conduit and pull boxes. The building architectural elements will only allow for a single layer of conduits (not stacked). The main horizontal pathway system consists of five 100 mm (4 in) conduits. Large single sheath copper cables are not expected to be placed. Which of the following is the MINIMUM width pull box that is to be provided?

Question

Quizplus · Accepted Answer

The minimum width of the pull box should be at least 48 inches (1220 mm) because the National Electrical Code (NEC) requires that the pull box be at least 6 times the diameter of the largest conduit when conduits enter and exit on the same side. Since the largest conduit is 100 mm (4 in), 6 times 4 inches is 24 inches, but since there are multiple conduits, the width must accommodate all conduits side by side, leading to a minimum of 48 inches.

You Are Designing a Horizontal Pathway System Where You Will