How do you isolate the overhead power supply?

How do you isolate the overhead power supply?

• A. Lower pantograph
• B. Notify supervisor and wait
• C. Contact Metrol - Metrol then Electrol (overhead power supplier)
• D. Switch off the substation main switch

Answer: (C)

Isolating overhead power supply must be done by the organization that owns and operates the line. The correct approach is to contact the overhead power supplier and have them perform the de-energization, issue clearance, and apply lockout/tagout as needed. In this scenario, that means getting Metrol to initiate the process, then coordinating with Electrol to actually isolate the overhead circuit. This ensures the line is truly de-energized and safe to work on. Lowering a pantograph isn’t a reliable isolation method because the system can still be energized from other feeders or points, and it may not be under control of the local crew. Simply notifying a supervisor and waiting delays safety actions and doesn’t remove the electrical hazard. Switching off the substation main switch might cut power at that substation, but it may not isolate the specific overhead section you’re dealing with, especially if the line is fed from multiple sources. The power supplier has the authority, access, and procedures to safely de-energize the overhead network and coordinate the necessary protections before work begins.

Isolating overhead power supply must be done by the organization that owns and operates the line. The correct approach is to contact the overhead power supplier and have them perform the de-energization, issue clearance, and apply lockout/tagout as needed. In this scenario, that means getting Metrol to initiate the process, then coordinating with Electrol to actually isolate the overhead circuit. This ensures the line is truly de-energized and safe to work on.

Lowering a pantograph isn’t a reliable isolation method because the system can still be energized from other feeders or points, and it may not be under control of the local crew. Simply notifying a supervisor and waiting delays safety actions and doesn’t remove the electrical hazard. Switching off the substation main switch might cut power at that substation, but it may not isolate the specific overhead section you’re dealing with, especially if the line is fed from multiple sources. The power supplier has the authority, access, and procedures to safely de-energize the overhead network and coordinate the necessary protections before work begins.