What is the minimum length for a pull box when two runs of three-inch RMC are installed adjacent to each other?

To determine the minimum length for a pull box when two runs of three-inch rigid metal conduit (RMC) are installed adjacent to each other, it is essential to consider the installation guidelines dictated by the National Electrical Code (NEC) or local regulations. The NEC provides specific requirements for pull box sizing based on conduit size and the number of conduits involved.

In general, when calculating the necessary length of a pull box, the width of the conduits and the number of conduits are taken into account. A common rule of thumb is that the length of the pull box should be at least 12 inches plus twice the diameter of the largest conduit when multiple conduits are involved. In this case, since there are two runs of three-inch conduit, each having a diameter of three inches, the calculation would look like this:

1. Start with the length requirement based on the diameter of a single conduit. For three-inch conduits, you'd calculate as follows:

• Length = 12 inches + 2 times the diameter of the conduit

• Length = 12 inches + (2 * 3 inches)

• Length = 12 inches + 6 inches

• Length = 18 inches

2. However, since