How long must a load operate to be classified as a continuous load?

A load is classified as a continuous load when it operates for three hours or more. This definition is significant in electrical inspections and planning because continuous loads require special consideration in terms of equipment sizing, circuit design, and overall electrical infrastructure. Continuous loads are typically those that run for an extended period and can affect the thermal limits of conductors and other equipment.

In this context, understanding the distinction is essential for safety and efficiency in electrical installations. Classification of loads is crucial for ensuring that conductors are adequately rated to handle the heat generated over long periods without exceeding the temperature limits that could lead to insulation failure or fire hazards. Thus, defining a continuous load as one that operates for more than three hours is an industry standard that helps ensure compliance with safety codes and practices.