What type of fittings are permitted to isolate an equipment enclosure from a metal raceway?

The correct answer, listed nonmetallic raceway fittings, is permitted to isolate an equipment enclosure from a metal raceway due to their nonconductive properties. This isolation is crucial for ensuring electrical safety, as it prevents the possibility of unintended electrical paths that could lead to ground faults or electric shock. Nonmetallic fittings effectively separate the equipment from the conductive metal raceway, allowing for safer installation in environments where electrical interference or hazards may be a concern.

In contrast, plastic raceway fittings may not have the same degree of functionality or certification as listed nonmetallic fittings, potentially leading to non-compliance with safety standards. Metallic raceway connectors and threaded metal fittings do not provide isolation, as they are conductive and could facilitate a direct electrical path between the enclosure and the raceway, thereby increasing the risk of electrical issues. Therefore, the use of listed nonmetallic raceway fittings is the appropriate choice for isolating equipment in a safe and effective manner.