What is the maximum weight a ceiling fan can be supported by an outlet box designed for such use?

The maximum weight a ceiling fan can be supported by an outlet box designed for such use is indeed 70 lbs. This weight capacity is established in the National Electrical Code (NEC), which outlines safety standards and guidelines for electrical installations, including the support of ceiling fans.

When installing a ceiling fan, it is essential to utilize an outlet box specifically rated for ceiling fans, as these boxes are engineered to handle the dynamic loads and vibrations that come from the operation of a fan. A standard electrical junction box typically does not have the same load-bearing capacity and may lead to safety hazards if a fan is installed improperly. Therefore, understanding the rated weight limit for different types of outlet boxes is crucial to ensure proper installation and operation, as well as to prevent potential failures that could result from overloading.