A 4 AWG equipment grounding conductor can be marked by what color of tape?

The correct choice for marking a 4 AWG equipment grounding conductor is green. In the context of electrical systems, the color green is universally recognized for indicating grounding conductors. This standardization is important for safety, as it provides clear identification of grounding wires to anyone working on or inspecting electrical systems.

Proper marking helps prevent confusion with other conductors, such as those carrying current, and ensures that personnel can readily identify the purpose of a wire. The National Electrical Code (NEC) and various industry standards emphasize the use of green for equipment grounding conductors to promote safety and compliance across electrical installations.

The other colors mentioned serve different purposes; for instance, red typically indicates a secondary phase in three-phase systems, blue may denote an alternative phase or a specific circuit, and yellow is often used for switch legs or as a conductor for auxiliary systems. These distinctions reinforce the crucial role of color coding in electrical work for both recognition and safety.