Transmission lines have characteristics that make them different from distribution lines. Because of the high voltages associated with transmission lines and the increasing use of multiple transmission lines on a given right-of-way, or even on individual structures, linemen who work on de-energized transmission lines need to be aware of some special considerations.
This training program focuses on how to safely de-energize and isolate a transmission line. Specific attention is paid to how a de-energized transmission line can be made safe to work on, and how a transmission line can be safely restored to service.
SUBJECTS AND OBJECTIVES
De-Energizing, Isolating, and Tagging
- Describe the general procedures for de-energizing, isolating, and tagging a transmission line.
- Describe how a de-energized line can become energized by magnetic induction.
- Describe how a de-energized line can become energized by electric induction.
Static Charges and Ground Systems
- Describe how a de-energized line can become energized by static electricity.
- Describe three transmission grounding systems.
- Describe how grounding minimized the dangers of induced and static charges.
- Describe how charges may continue to be present on a line at locations other than the point of grounding.
Field Clearance and Testing
- Describe the general procedures for obtaining a clearance on a transmission line.
- Describe how to test a transmission line to determine that it is de-energized.
- Explain why it is necessary to ground a de-energized transmission line.
- Describe how to safely ground a transmission line.
Returning a Line to Normal
- Describe how to safely remove grounds from a transmission line
- Describe the general procedure for releasing a clearance.
- Describe the general procedure for switching a line back into service.