What does "box fill calculation" involve under Article 314?

Box fill calculation under Article 314 involves determining the total cubic inches required for conductors and devices within an electrical box. This calculation is crucial for ensuring that the box has adequate space to accommodate the wiring and devices without overcrowding, which can lead to overheating and potentially create a fire hazard.

The National Electrical Code specifies how to calculate box fill based on various factors, including the number of conductors, the presence of devices (like switches and outlets), and their sizes. Each component adds to the cumulative space needed within the box, and exceeding the prescribed fill limits can result in unsafe conditions. Therefore, ensuring that the box can safely and effectively contain all electrical elements is a vital practice in electrical installations.