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HV Test Equipment


Breaker Testing

Circuit Breaker Time and Motion Testing

Determining mechanical condition of high-voltage circuit breakers BY JOZEF LEVI, Doble Engineering Company Life expectancy of a newly installed high-voltage circuit breaker is approximately 40 years. Throughout its life, under normal circuit conditions, the circuit breaker will operate less than...


Utility Proactively Tests Underground Cable

Distribution companies are continually looking for ways to improve system reliability, all while conserving capital investments and operational costs. With an aging infrastructure, one of the main issues that utilities face is a way to assess the actual condition of their capital assets. With...

Insulation Resistance Test

Insulation Resistance (IR) test, often called Megger test, is more than 100 years old and assumed to be a very straightforward test. During my inspection and testing work in the past 15 years in Canada, US, and internationally, I have seen different practices of performing and interpretation of IR...


IR Inspection Windows for Electrical System Reliability

An Infrared Inspection Window is used to separate environments of differing pressures or temperatures while allowing light energy at a specified electromagnetic wavelength to pass between the two environments. They must meet the strength and environmental requirements for the type of equipment in...

HV Testing

Partial Discharge & Circuit Breaker Asset Management

Detecting and avoiding preventable failures

BY JAY GARNETT, Doble Engineering Company

While metal clad switchgear can be very reliable, sometimes operating for over 50 years, throughout the aging process, this group of electrical disconnect switches, fuses and circuit breakers can experience issues such as moisture ingress, animal intrusion, enclosure rusting, and insulation deterioration. One efficient approach to detect incipient failures is partial discharge (PD), a leading indicator of various failure modes. Using both acoustic and...

HV Test Equipment Articles