NEC Commercial Electrical Practice Test

Non-metallic cables must be secured at intervals not exceeding how many feet?

1. 3 1/2 ft

2. 4 ft

3. 4 1/2 ft

4. 5 ft

The correct answer is: 4 1/2 ft

Non-metallic cables, such as NM cables (commonly known as Romex), must be secured at intervals not exceeding 4.5 feet (54 inches) as per the National Electrical Code (NEC). This requirement ensures that the cables are adequately supported and protected from physical damage and strain. Proper securing prevents sagging and potential damage that could result from movement or external forces, which might compromise the electrical integrity of the wiring system. This distance is critical for maintaining the safety and functionality of electrical installations, as it reduces the likelihood of accidents caused by loose or improperly supported cables. It's important to adhere to this requirement during installation to comply with code standards and ensure the longevity and safety of the electrical system.