What type of support should open conductors be mounted on?

Open conductors should be mounted on glass or porcelain knobs to ensure both safety and functionality. Glass and porcelain are non-conductive materials, which prevent current from diverting or leaking and are resistant to deterioration from environmental factors. These materials also have a high insulation resistance, and their smooth surface facilitates easy installation and maintenance of the conductors.

This mounting method is specifically important for applications where conductors must be kept away from other surfaces and properly spaced to maintain clear air gaps, which is essential for preventing electrical shorts or accidental contact. The use of glass or porcelain knobs aligns with code requirements for maintaining the integrity of the electrical system in various installation environments, especially in older wiring systems still governed by traditional practices.

While plastic mounts, metal brackets, and copper hangers may seem feasible, they do not offer the same level of insulation or protection required for open conductors, which is why the choice of glass or porcelain is preferred in practice.