Why is it important to account for both motor and non-motor loads in load calculations?

Accounting for both motor and non-motor loads in load calculations is essential because motors often draw significantly higher starting currents than their running currents. When a motor starts, it requires an influx of energy to overcome inertia, which can result in a starting current that is several times greater than the current when the motor is operating at its rated capacity. Failing to consider this high starting current can lead to undersized circuits, overloading of feeder conductors, and tripping of circuit breakers, which could compromise both the safety and efficiency of an electrical system.

Furthermore, accurately determining the total load on a system involves considering both types of loads. Non-motor loads, such as lighting and receptacles, also contribute significantly to the overall current draw and must be accounted for to ensure the system is designed to handle the total demand.

In summary, accurately incorporating the high starting currents of motors into load calculations enables proper sizing of circuit components and helps ensure reliability and safety in electrical installations.