According to NEC guidelines, how should raceways be secured as detailed in Article 300.12?

The requirement for raceways to be securely fastened to structures as stated in Article 300.12 of the National Electrical Code (NEC) emphasizes the importance of ensuring that raceways are properly installed for safety and functionality. Securely fastening raceways helps prevent issues such as physical damage, electrical hazards, and potential failure of the electrical system.

By requiring raceways to be secured, the NEC aims to maintain the integrity of the installation, preventing movement that could lead to stress on the conductors inside or create loose connections. This requirement is particularly vital for maintaining compliance with safety standards, as unsecured raceways can become a liability in any electrical system.

The other options do not align with the NEC's focus on safety and reliability. Loosely attaching raceways, regardless of flexibility, could lead to movement and damage over time. Additionally, raceways that are covered still require proper support to ensure they remain secured and safe. Finally, while there are specific spacing requirements for supporting certain types of raceways, the blanket statement about supporting raceways every 10 feet does not universally apply to all types of raceways as specified in NEC guidelines. The emphasis on secure fastening is paramount for a robust electrical system.