For loads likely to be ON for 8 hours, how should the computed load for sizing branch-circuit conductors and OCPDs be calculated?

When sizing branch-circuit conductors and overcurrent protective devices (OCPDs) for loads that are anticipated to be continuous, such as those expected to be on for 8 hours, applying an appropriate safety factor is critical to ensure proper operation under prolonged use. For continuous loads, the National Electrical Code (NEC) stipulates that the load must be calculated at 125% of the actual load. This adjustment accounts for potential increases in load and helps prevent overheating and ensures that the equipment can safely handle the current without tripping the protective devices.

This approach is based on the understanding that continuous operation can lead to conditions where a normal load could potentially exceed the device's rating under sustained usage. By incorporating this 125% factor, you provide a buffer that supports the reliability and safety of the electrical installation, particularly in environments where equipment might be running indefinitely at or near full capacity. Thus, the correct way to calculate the computed load for sizing in this scenario is to multiply the actual load by 125%.