P35.010: Live Working

Live Working Reference Guide (Tan Book): This is a comprehensive technical resource on live working, including deenergized work, North American and international standards, and fundamentals and principles related to live working tools, equipment, methods, and training resources. The guide is designed to be used by utility personnel engaged in all aspects of live work, from transmission maintenance managers and supervisors to line workers. A new version of the guide is published each year, including new or revised content based on input from project members.

Live Working Rope Testing and Evaluation: Dielectric ropes are used in live work along with rigid insulating tools. Currently available live working ropes have several advantages and disadvantages. An updated research plan intends to evaluate the electrical and mechanical performance of new rope designs coming to market as well as aged ropes. Testing has been performed according to existing standards but also based on “real-world” conditions. In 2025, EPRI intends to publish a technical update detailing results of electrical testing of synthetic ropes used in stringing operations in “real-world” conditions, such as exposure to fog.

Evaluation of Portable Rope Testing Devices: Devices known as dielectric rope testers are used to determine if the dielectric characteristic of the rope is safe for contact with energized lines. This task intends to identify the commercially available rope testers and conduct tests to evaluate their performance. In 2025, results from the testing of commercially available detectors are intended to be presented in a report.

Minimum Approach Distance Calculator (Software): This desktop software tool calculates and illustrates the minimum approach distance (MAD) for phase-to-ground and phase-to-phase clearances based on the Institute of Electrical and Electronics Engineers standard IEEE-516 and The International Electrotechnical Commission standard IEC-61472 formula for utility-specific structures using line components and dimensions for that structure’s location. In 2025, EPRI intends to update the software with new realistic features, continue updating the insulator model builder, and initiate the structure model builder. This new module is envisioned to enable users to create their custom structures, including features such as underbuilt conductors, braced pole configurations, and asymmetric crossarms.

Temporary Protective Grounding Rating Calculator (Software): This calculator is intended to quickly calculate the parameters for sizing temporary protective ground cable based on thermal constraints. This software calculates maximum clearing time, maximum current, temperature, and associated cable cross-section according to ASTM standard. In 2025, EPRI intends to update the software.

Understanding Insulating Tool Flashovers at Normal AC Voltages: This multi-year task supports and complements industry and member problem-solving efforts related to past industry insulating tool flashovers at normal ac system voltages by investigating the incidents and developing and performing laboratory tests based on hypotheses and/or numerical models to evaluate them as viable flashover mechanisms.

This research is part of a broader research effort that intends to investigate degradation and failure modes of insulating tools, research new materials to enhance tool performance, develop/search for new tool testing and inspection technologies, and develop reference and training materials that enhance worker safety in the use, inspection, testing, and care of insulating tools used in live work. In 2025, EPRI intends to verify the validity of the finite element modeling developed in 2023 and 2024 by means of small-scale testing.

Conductive Suit Evaluation: This task aims to update and expand the investigation of conductive suits performed in 1995. It seeks to verify the electrical performance of conductive suits available on the market, including shielding efficiency, current carrying capacity, and electric resistance degradation because of washing cycles. In 2025, EPRI intends to expand the investigation and test conductive suits from two additional manufacturers. Results from the testing of the conductive suits performed in 2024 and 2025 are intended to be presented in a report.

Understanding Effects of High Temperature on Insulating Tools: This multi-year task seeks to identify mechanical and electrical effects on insulating tools, such as hot sticks and ropes, caused by contact exposure with conductors operating at high temperatures. This task is important because utilities have replaced conventional aluminum conductor steel reinforced (ACSR) for high temperature, low sag (HTLS) conductors to operate at temperatures up to 250°C.