The requirement for marking in a 4-wire, delta-connected system refers to which term?

• A. Identification of conductor or busbar
• B. Damp or wet locations
• C. Natural circulation of air
• D. Gases, fumes and vapors, liquids

Answer: (A)

In a four-wire delta-connected system, marking is all about clearly identifying which conductor is which and which busbar they connect to. This labeling ensures anyone working on the system knows which wire is hot, which is neutral, and how the phase connections relate to the equipment. The neutral is present in this setup, and in some delta configurations (like high-leg delta) one leg has a special status that must be clearly identified so it isn’t misconnected. Proper marking prevents mistakes during installation, maintenance, or future modifications, and supports safe, code-compliant operation.

Environmental or hazardous-location aspects, like damp locations, ventilation, or gases and vapors, aren’t what marking requirements focus on. Those relate to where equipment can be installed, not to labeling conductors.