What is the purpose of a cover on an electrical box?

The purpose of a cover on an electrical box is fundamentally to protect the connections and components inside the box from physical damage and moisture. Electrical connections must be safeguarded from environmental factors, such as water, dust, and accidental contact, which can lead to short circuits, malfunctions, or even electrical fires. By having a cover, the integrity of the electrical system is maintained, ensuring safety and reliability.

While other functions, such as aesthetic enhancement or securing the box, may be considerations in some contexts, the primary and most critical role of an electrical box cover is protection. Ventilation is generally not a function of box covers; in fact, many electrical boxes are designed to be enclosed to prevent moisture ingress, rather than to facilitate airflow.