According to NFPA 70, what is the maximum unsupported length of 1/2-inch flexible metallic conduit where flexibility is required after installation?

The maximum unsupported length of 1/2-inch flexible metallic conduit, as specified by NFPA 70, is indeed 4 1/2 feet when flexibility is required after installation. This regulation is established to ensure that the conduit maintains its intended flexibility and isn't subjected to undue stress or strain that could lead to damage or failure over time.

Flexible metallic conduit is designed to allow for movement, and improper support over longer distances could compromise this ability, potentially creating a hazard. By limiting the unsupported length to 4 1/2 feet, the NEC (National Electrical Code), which is referenced in NFPA 70, promotes safety and functionality in wiring installations. Understanding this limit is essential for ensuring proper installation practices and compliance with established electrical safety standards.