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Overview & Events

Research Value

  • A quantitative understanding of aging and deterioration rates.
  • A better understanding of the expected life of circuit breaker materials.
  • Knowledge for implementing a condition-based maintenance and replacement approach.
  • Third-party, unbiased assessment of online monitoring technologies’ life-cycle costs to aid industry specification and interpretation.
  • A technical basis to help assess and manage risks.
  • Reduced unplanned expenses and increased benefits and value of planned work.
  • Controlled life-cycle costs and risks, which contribute to reduced operating costs.

Member Benefits

  • Effective knowledge transfer through the Circuit Breaker Guidebook and regular technical webinars. The guidebook is a comprehensive collection of circuit breaker knowledge designed specifically for utility owners and operators.
  • Novel techniques for sealing SF6 leaks in circuit breakers and GIS components —which, in turn, translates into reduced emissions, O&M and improved reliability through life extension.
  • Quantifiable data on breaker materials and subsystem performance – which, in turn, translates into development and implementation of effective maintenance and replacement strategies

At A Glance

The life-cycle performance of a circuit breaker is determined by the performance and condition of its materials and components. Together, these performance criteria drive the requirements for maintenance and refurbishment or replacement. However, there is little quantifiable data on breaker materials and subsystem performance available to inform decisions and design cost-effective condition-based maintenance or replacement programs. Utility maintenance practices vary widely, as do manufacturers’ recommendations. This research addresses the need to develop information, techniques, and methodologies to support best practices in high-voltage circuit breaker life management. The methods developed for transmission classes may be adapted so that these methods can be applied to medium-voltage (13.8–69 kV) breakers.

The objectives of the proposed research are to better understand circuit breaker operating stresses, underlying failure modes, and degradation rates and to provide utilities with knowledge and guidelines for selection, application, procurement, maintenance, and condition assessment and testing to ensure satisfactory circuit breaker life-cycle performance. It is anticipated that the research efforts could result in:

  • Methods to assess aging of gas-insulated switchgear (GIS) and circuit breaker component and subsystems, including identification of failure modes and degradation mechanisms.
  • Innovative SF6 leak-sealing techniques for breakers and GIS.
  • Noninvasive condition assessment techniques.
  • Assessment of diagnostic effectiveness of online monitoring as well as offline testing.
  • Guidance for handling SF6
  • Maintenance guidelines.
  • Reference books, guidelines, videos, field guides, and technology transfer workshops.
  • Collaborative forums for sharing lessons learned and best practices.

Research Highlights

Circuit Breakers Online Monitoring Effectiveness Assessment develops and applies assessment metrics to various circuit breaker online monitors to determine which monitors and tests provide the most useful information. The objective is to provide utilities guidance on the most informative and cost-effective procedures for nonintrusive diagnostics to support condition-based maintenance. Efforts to date have identified commercially available as well as emerging technologies and documented the claimed capabilities as well as utility experience from using specific online monitors. Based on the findings a plan has been formulated to evaluate their effectiveness. Efforts in 2024 intend to work with funders to identify specific circuit breaker monitors of the highest interest and implement the evaluation approach to make comparisons and assess their efficacy. If successful, the results provide valuable assistance in monitor specification, reliability, interpretation, and adoption.

Circuit Breakers Diagnostics Effectiveness Assessment develops and applies metrics to assess the effectiveness of various circuit breaker diagnostic techniques. The objective is to provide utilities guidance on the most informative and cost-effective procedures for nonintrusive diagnostics to support condition-based maintenance.

  • Assessing the efficacy of circuit breaker dynamic resistance measurements (DRM): Work is underway to assess the effectiveness of DRM, an offline non-intrusive diagnostic test to assess the condition of circuit breaker interrupter arcing contacts. Laboratory tests performed to date demonstrate the technique’s ability to detect artificially degraded contacts. Laboratory and field tests continue in 2024 to determine the relationship between the DRM waveform and contact condition and build a library for different circuit breaker interrupter models.

  • Efforts in 2024 also intend to expand efficacy assessment to other techniques, for example, X-Rays, Timing and Travel etc. and explore opportunities to utilize relays for circuit breaker monitoring.



SF6 Leak Sealing for Circuit Breakers and Gas-Insulated Substations investigates methods that can be used by utilities to cost-effectively seal SF6 leaks. The emphasis is on identifying materials and techniques that can seal while maintaining equipment operating pressures and are easy to apply and remove by utility personnel without having to resort to outside service providers, clamps, or molds. Efforts to date have developed novel techniques for sealing leaks on circuit breaker and GIS component geometries at ground potential. For example, leaks in porous wields, o-rings in flange and threaded fittings. Three successful techniques identified in the laboratory testing are being tested in the field at utility sites. Efforts in 2024 intend to:

  • Develop techniques for other geometries. For example, leaks in the bushing flange interface. Some of these new geometries may not be at ground potential.

  • Investigate scaling application of existing techniques to larger flange diameters.

  • Continue search for innovative methods used by other industries.

  • Continue investigations to find sealants that cure at lower temperatures.

  • Monitor the performance of the field trials.

  • For techniques that are successful in the field develop application guides and “how-to” videos.

Engagement Opportunities

Meeting Date Location Information
EPRI Kick Off Webcast: P37.102 Circuit Breakers Life Management & P37.108 GIS and GIL (Gas Insulated Substations and lines)
Task Force		 February 7
11:00 am - 12:00 pm ET		 Webcast Meeting Materials
Circuit Breakers & GIS
Task Force		 February 19-22 (In-person)
February 26-29 (Virtual)		 Charlotte, NC Meeting Materials
Substations 2025 ARP Rollout #1 June 25
10:00 am - 11:30 am ET		 Webcast Meeting Materials
EPRI R&D Project Update: P37.102 Circuit Breakers Life Management & P37.108 GIS and GIL (Gas Insulated Substations and lines) July 18
11:00 am - 12:30 pm ET		 Webcast Meeting Materials
Substations 2025 ARP Rollout #2 August 6
2:00 pm - 3:30 pm ET		 Webcast Meeting Materials
Circuit Breakers & GIS
Task Force		 August 19-22 (In-person)
August 26-29 (Virtual)		 Charlotte, NC Meeting Materials
EPRI Substations (Program 37) New Supplemental Launch Webcast October 10, 1:00pm - 2:00pm ET Webcast Meeting Materials
P37.102 Circuit Breakers Life Management & P37.108 GIS and GIL (Gas Insulated Substations and lines) End-of-Year Webcast November 14
11:00 am - 12:00 pm ET		 Webcast
P37.102 Circuit Breakers Life Management & P37.108 GIS and GIL (Gas Insulated Substations and lines) December 10
11:00 am - 12:00 pm ET		 Webcast Webcaset Information
Circuit Breakers & GIS Task Force - March 2025 March 10-13 (In-person)/ March 17-20 (Virtual) Charlotte, NC Register Here