What is the minimum requirement for service conductors in terms of load calculation?

The correct choice specifies that service conductors must be sized to accommodate 125% of the continuous load in addition to 100% of the noncontinuous load. This approach is grounded in the National Electrical Code (NEC) which recognizes the different natures of continuous and noncontinuous loads.

Continuous loads are those that are expected to run for three hours or more, while noncontinuous loads can vary and are typically not intended to run for extended periods. To ensure safety and reliability, the NEC requires that conductors be rated above the actual demand to prevent overheating. By applying 125% to the continuous load, the sizing of the service conductors accounts for potential overload scenarios. Additionally, the full value of the noncontinuous load is included because it can be expected to run simultaneously with the continuous load, stressing the importance of proper conductor sizing to prevent potential hazards such as damage or failure due to overheating.

Selecting the correct conductor size in this manner helps in maintaining the overall efficiency of the electrical system and enhances safety by allowing for occasional peaks in the electrical load without compromising the integrity of the wiring.