CIRCUIT BREAKER DESIGN AND OPERATION FOR COLD WEATHER PERFORMANCE
This month’s Featured Technical Paper is from the Proceedings of the 2022 International Conference of Doble Clients. The paper is titled: Circuit Breaker Design and Operation for Cold Weather Performance.
The service territory of American Electric power (AEP) spans from 25° to 42° north latitude with ratings from 4 kV to 765 kV and an extensive range of circuit breaker technologies. In 1994, an unusual cold snap prompted AEP to, among other things, implement a revised low temperature specification of -33 deg. C (- 28 deg. F). In addition, AEP has standardized its operating procedures related to low density lockout and worked closely with circuit breaker manufacturers to improve low temperature service reliability.
IEEE high voltage circuit breaker standards specify -30 deg. C (-22 deg. F) as the normal low temperature service condition. However, many parts of North America require reliable outdoor operation in considerably colder conditions. The work herein suggests use of publicly available climate data combined with established statistical methods as a means to inform equipment specifications and reliable application in service. Two relevant examples are given.
Furthermore, several aspects of design for low temperature service are presented. In particular, the concurrent effect of wind and low temperature is examined relative to need, design and test. Other design factors related to low temperature service and the need to balance low and high temperature performance are reviewed in the context of mechanism materials, lubricants and elastomeric gas seals.
Finally, while icing is typically only addressed as a static circuit breaker load, we point out that close cooperation between manufacturer and end user may also prevent icing issues in service related to kinematic resistance.
Doble Service Agreement Clients
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