Journeyman Electrician Exam (NEC)Wiring Methods and MaterialsEasy
A residential electrician is installing a new ceiling fan with a support box. The fan weighs 45 pounds. What is the minimum weight rating required for the outlet box supporting this ceiling fan?
- A70 pounds
- B50 pounds
- C35 pounds
- D40 pounds
Show answer & explanationAnswer & explanation
Correct answer: B. 50 pounds
According to NEC Section 314.27(C), boxes used to support ceiling-suspended fans that weigh up to 35 pounds must be listed for the purpose and marked. For fans weighing over 35 pounds, the box must be listed and marked for the maximum weight it's intended to support, but a minimum general rating for ceiling fans over 35 lbs is commonly 50 lbs or more. Since 45 pounds is over 35 pounds, a 50-pound rated box is the most appropriate minimum choice from the options.
Why the other options are wrong
- A. 70 pounds is higher than required and would be acceptable but not the minimum.
- C. 35 pounds is the standard maximum for a listed box without a specific fan weight rating, but a 45lb fan exceeds this.
- D. 40 pounds is above 35 pounds but not a standard minimum rating found for fan boxes over 35 lbs; 50 lbs is the common next step.
Ceiling Fan Box Support
Outlet boxes used to support ceiling-suspended fans must be specifically listed for the purpose and have a weight rating appropriate for the fan it will support.
- Standard boxes can support up to 35 lbs without specific marking.
- Fans over 35 lbs require boxes listed for the specific weight.
- Maximum fan weight for any box is generally 70 lbs (314.27(C)).
Memory trick: Fan boxes have limits, check the 'weight tag' to prevent a drop.