What type of materials must the mechanical linkages connected to movable contacts be constructed from?

The mechanical linkages connected to movable contacts must be constructed from nonconductive materials to ensure that there is no unintended electrical conduction between the components of the system. Nonconductive materials provide insulation, which helps to prevent electrical shorts or accidental contact with live electrical parts. This is crucial for maintaining safety and proper functioning of electrical equipment.

While conductive materials could facilitate electrical flow, they would compromise the isolation necessary in the mechanical linkages. Composite materials can vary in their properties, and although some may be nonconductive, they are not inherently suitable for all applications involving electrical isolation without specific treatment. Metallic materials are also conductive by nature and would lead to risks of short circuiting in scenarios where insulation is essential.

Using nonconductive materials for mechanical linkages thus ensures safety and reliability in the operation of electrical systems, making it the appropriate choice for this application.