What color insulation is typically used for 120/240V single-phase conductors?

The typical color insulation used for 120/240V single-phase conductors includes black for the hot phase, red, which is often used as a second hot conductor in certain configurations, and white, which is designated for the neutral wire. This color coding is outlined in the National Electrical Code (NEC) and is crucial for ensuring that electricians and other individuals working with electrical systems can easily identify the function of each wire.

Black is used for one of the 'hot' wires, while red serves as an additional hot conductor in configurations involving two-phase circuits or as a switch leg. The white wire, being the neutral, is critical for completing the circuit and facilitating the return of current back to the power source in a safe manner. This standardization improves safety and reduces the risk of errors during installation or maintenance.