In a grounded system, how should normally noncurrent-carrying electrically conductive materials be connected?

In a grounded system, normally noncurrent-carrying electrically conductive materials should be connected together and to the electrical supply source to ensure safety and proper functioning. This practice helps prevent the buildup of static electricity and minimizes the risk of electric shock or accidental contact with live parts. By grounding these materials, any stray voltage or fault currents that occur can safely dissipate into the ground, which reduces the chance of electrical hazards for personnel and equipment. This grounding provides a reference point for the electrical system and protects users by ensuring that even when these materials are inadvertently energized, they will direct the current safely into the ground.

The other options do not provide adequate safety measures. Isolating and securing these materials could lead to static buildup or accidental contact with live parts, while loosely and flexibly connecting them could lead to unstable conditions and potential hazards. Leaving them unconnected could create opportunities for dangerous contacts or voltage differences that could cause unwanted electrical events. Thus, proper grounding remains essential for safety in electrical systems.