Ceiling-suspended fans are required to be installed on boxes marked as suitable for what purpose?

Ceiling-suspended fans must be installed on boxes specifically marked for fan installation due to the unique load requirements and conditions associated with ceiling fans. These fans typically have more substantial weight and dynamic loads compared to standard light fixtures.

Boxes that are labeled for fan installation are designed to support not only the weight of the fan but also the movement and vibrations generated when the fan operates. This ensures stability and safety during use. Using a box not rated for fan installation can lead to potential hazards, including the risk of the fan being improperly supported, which may result in failure and create dangers such as falling or malfunctioning fans.

While boxes marked for lighting installation might handle the weight of a light fixture, they do not provide the structural integrity required for ceiling fans, which is why it is essential to follow the manufacturer's recommendations and electrical codes regarding the proper installation boxes for various fixtures.