Which method is NOT used to guard bare live parts from the public according to the NEC?

The method that is not recognized by the National Electrical Code (NEC) for guarding bare live parts from the public is the use of a fireproof curtain. While the NEC emphasizes the importance of ensuring safety around electrical installations, it does not endorse the use of fireproof curtains as a primary or acceptable means of protection against accidental contact with live parts.

The other methods listed are established practices that comply with NEC safety requirements. Enclosing bare live parts in metal cabinets provides a robust barrier that prevents unauthorized access. Installing electrical components behind locked barriers effectively deters casual or unintentional contact, ensuring that only authorized personnel can access them. Covering live parts with insulated barriers is also a recognized measure; it directly protects individuals from electrical hazards by providing a non-conductive layer over exposed components. Each of these methods aligns with the NEC's commitment to safeguarding the public while working with or around electrical systems.