Outlet boxes designed to support ceiling-suspended fans weighing more than what should have a maximum weight marked on the box?

Outlet boxes designed for ceiling-suspended fans must be able to support more than just the weight of the fan; they should also accommodate any additional stress from the fan's motion, such as vibrations and torque during operation. The National Electrical Code specifies that outlet boxes intended to support ceiling fans must indicate a maximum weight.

For fans weighing more than 35 pounds, it is critical that the supporting outlet box is specifically rated for that weight to ensure safety and compliance with the NEC. A box that is marked with a maximum weight rating of 35 pounds ensures that it meets the structural and electrical safety requirements for securely supporting heavier fans, thus reducing the risk of failure during use. This rating is crucial for preventing potential hazards such as the fan falling, which could lead to property damage or personal injury.

The other weight options, while significant, do not reflect the NEC standard for heavier ceiling-suspended fans, making them unsuitable choices in this context. Therefore, a ceiling fan exceeding 35 pounds necessitates a corresponding outlet box that is specifically marked for that weight to ensure compliance with safety standards.