Which scenario could energize a de-energized line due to physical contact?

Which scenario could energize a de-energized line due to physical contact?

• A. Insulation aging
• B. Regularly scheduled maintenance
• C. Opening a breaker while loaded
• D. Energized lines contacting de-energized lines

Answer: (D)

When a live conductor physically touches a line that is not energized, current will flow from the energized line into the other conductor. That contact equalizes potentials along the connected path, so the previously de-energized line becomes energized. This creates a dangerous condition: the fault can energize equipment, cause arcs, and pose a severe shock hazard to anyone nearby. The other scenarios don’t create that direct energizing effect. Insulation aging can lead to leakage or faults through degraded insulation, but it doesn’t by itself energize a separate line through contact. Regular maintenance is performed on de-energized equipment for safety and does not energize lines. Opening a breaker while the system is loaded interrupts current and reduces risk of ongoing energization; it does not energize another line by contact.

When a live conductor physically touches a line that is not energized, current will flow from the energized line into the other conductor. That contact equalizes potentials along the connected path, so the previously de-energized line becomes energized. This creates a dangerous condition: the fault can energize equipment, cause arcs, and pose a severe shock hazard to anyone nearby.

The other scenarios don’t create that direct energizing effect. Insulation aging can lead to leakage or faults through degraded insulation, but it doesn’t by itself energize a separate line through contact. Regular maintenance is performed on de-energized equipment for safety and does not energize lines. Opening a breaker while the system is loaded interrupts current and reduces risk of ongoing energization; it does not energize another line by contact.