Which term describes the back-feed from a generator causing unplanned energizing?

• A. Controlled Energizing
• B. Normal Energizing
• C. Inadvertent Energizing
• D. Induced Energizing

Answer: (C)

Back-feed from a generator energizing a circuit that should be dead is called inadvertent energizing. This happens when a generator is connected to a bus, feeder, or switchgear in a way that allows power to flow back into parts of the system that are supposed to be de-energized. The result is unplanned voltage appearing on equipment, disconnects, or lines, which can create shock or arc-flash hazards for workers who think the area is safe.

Why this term fits: it captures the idea that the energizing is accidental or unintended, not part of the normal or planned operation. It’s not a designed or controlled energizing sequence, and it isn’t caused by magnetic coupling from nearby energized lines (which would be induced energizing). Understanding this helps emphasize the need for proper isolation, transfer switches, and lockout/tagout to prevent back-feed and keep de-energized circuits truly safe.