P35.018: Transmission Line Switch Management

Test Quick Break Whip Devices: This task intends to develop guidelines and determine, through laboratory testing, the performance and current handling of quick break whip arc interrupting devices. Since there is currently no test methodology for evaluating quick break whips, this research is intended to advance the knowledge and understanding of laboratory evaluation of these devices. In 2027 EPRI intends to develop a free-air arc model based on the high voltage electrical test results. In addition, EPRI intends to continue with the endurance (cyclic) tests of whips, and develop guidance for selecting arc-extinguishing devices based on line characteristics and parallel operation with other circuits.

Develop Inspection and Maintenance Considerations for Line Switches: This is a living task which investigates the use and application of existing, new, and emerging technologies for inspecting, assessing, and monitoring the health conditions of line switches and accessories. The information obtained is intended to be compiled into a comprehensive guide, to form the basis for understanding components, inspection, and monitoring techniques. Technologies such as unmanned aerial systems, testers and sensors are intended to be explored. In 2027 EPRI intends to continue testing the mechanical performance of bearing systems. In addition, EPRI intends to work on the development of a tool for remote cleaning of finger- and jaw-type contacts using insulating tools, expand inspection procedures for specific components, and update the ArcGIS Survey123 electronic form for inspection of line switches, as needed.

Develop Transmission Line Switch Vintage Guide: This task aims to develop a comprehensive technical resource intended to provide guidance and strategies on procedures to assess the condition of transmission line switches in service by model and vintage. For that, underlying failure and degradation modes and mechanisms have been identified and catalogued by components to help estimating life expectancy and required maintenance actions. In addition, this task assists utilities in the performance of root cause and failure analyses. In 2027, EPRI aims to work on and compile results of new forensic investigations, and compile case studies provided by utilities.

Catalog of Component Degradation Modes: This task aims to catalog degradation modes of line switch components across different manufacturers. In 2027, EPRI intends to update the Transmission Resource Center (TRC) with new findings from prior forensic investigations and utility reports.

Update Practical Installation Guide of Line Switches: This is a living task intended to provide the technical basis and guidelines to support and help in the field engineers and technical staff with information regarding component specification, design, installation, and commissioning protocols of new equipment, as learned through best practices. In 2027 EPRI intends to continue working on a compilation of utility line switch installation design templates, and on alternative primary power supply methods for motor operators and controls using voltage transformers.

Evaluate Motorized Switches: This task seeks to gain a better understanding of the functionality of, and the inspection techniques required for motorized switches compared to manually operated switches. Possible topics include the additional components needed for motorization, such as batteries, SCADA, and alternatives of power supply, including voltage transformers. Findings from this task are shared through the inspection and Maintenance Guide and the Line Switch Vintage Guide Technical Update.

Inspection and Maintenance of Line Switches – Workshop: EPRI intends to host an in-person workshop on inspection and maintenance of disconnect switches installed on overhead transmission line structures, including laboratory demonstrations.

Provide Tools and Resources on The Transmission Resource Center: The following calculators, tools, result summaries, and references are planned to be available on the Line Switch Transmission Resource Center: