According to NEC, which condition justifies the use of conduit fittings?

The condition that justifies the use of conduit fittings is when making bends or changes in direction. This is because conduit fittings are specifically designed to facilitate the connection of conduit sections in a way that allows for smooth transitions. Bends and directional changes in conduit runs require fittings to maintain the integrity of the electrical installation, ensuring that cables comfortably navigate without stress or damage.

Using fittings correctly not only aids in installation but also adheres to safety standards outlined in the National Electrical Code (NEC). Proper fittings help protect the conductors within the conduit from potential physical damage that could occur with sharp turns or angles if made without them. Thus, whenever a change in the path of the conduit is necessary—whether it be through a bend, a T-joint, or any turn—conduit fittings are essential to uphold those safety and operational standards.