Which type of load operates without interruption for more than three hours consecutively?

A continuous duty load is defined as a type of load that operates for more than three hours continuously without interruption. This characteristic is critical when considering electrical designs and load calculations, as it affects the capacity requirements of the electrical distribution system. Continuous duty loads include equipment such as motors and heaters that are intended to run for extended periods, and their design considerations must account for their sustained operation and heat generation.

In contrast, temporary loads are designed for short-term use, normal loads cover general daily operational use without strict criteria on duration, and peak loads refer to maximum levels of demand that may occur for short durations. Thus, the unique definition of a continuous duty load clearly establishes its criteria and importance in load calculations for feeders and services.