During a walk-through at a small warehouse PV system with a grounded DC array, a trainee traces two conductors landing on the grounding bar at the system's designated bonding point: a green wire from the metal combiner enclosure, and the array's negative conductor, marked with white tape. The electrician says one connection is equipment grounding and the other is system grounding. Which statement correctly describes what each connection does for safety and normal operation?

System grounding and equipment grounding solve different problems, and one bar can show both at a system's designated bonding point. The green wire from the metal combiner enclosure is an equipment grounding conductor: it bonds exposed conductive parts, so a contact between an energized conductor and metal can send fault current back to the source, allowing the protective device to clear the fault. The marked negative conductor carries normal current and is intentionally connected to the grounding system at the designated point; this system grounding establishes the circuit's voltage reference relative to earth. Treating both connections as equipment grounding ignores why a current-carrying conductor is connected at all. Reversing the roles assigns a reference function to a bonding wire and a bonding function to a conductor carrying load current. Fault current must return to the source to operate the protective device; the earth electrode is not normally an effective fault-current return path. Identify each conductor's job before naming it: the grounded circuit conductor carries normal operating current, while the equipment grounding conductor normally does not.