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Transformer Testing


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...

Power Factor Testing of Circuit Breakers

Detecting contamination and deterioration in SF6 breakers to ensure longevity BY LINDA NOWAK, Doble Engineering Company The purpose of “Doble testing”, or power factor testing, SF6 (sulfur hexafluoride) circuit breakers is to detect the presence of contamination and/or deterioration of the...

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...

Vacuum Interrupter Testing for Circuit Breakers

How to predict field life using vacuum interrupters BY FINLEY LEDBETTER, Group CBS Utilities have widely replaced older air-magnetic and oil interrupters for circuit breakers rated at one kilovolt (kV) or higher with vacuum interrupters (VI) due to higher interrupt capability. Vacuum interrupters...

Dynamic Resistance Measurement

Condition testing of circuit breaker’s arcing contacts BY BUDO MILOVIC, DV-Power The preventive maintenance on a high-voltage (HV) breaker consists of several routine tests. The timing and motion tests are methods used to assess the breaker’s mechanical condition. When the timing and motion...

HV Test Equipment

Solving Underground Cable Problems with Partial Discharge Testing

How to prevent failure with partial discharge testing

BY HENNING OETJEN, Megger

Partial discharge (PD) measurements are increasingly used as a reliable and non-destructive diagnostic method to detect weak spots in the insulation of underground cables. Routinely, partial discharge measurements are utilized in laboratories for testing cable reels prior to commissioning and in the field to verify installation quality.

Typically, many factory-testing standards require that workers use a 50/60 hertz (Hz) high-voltage...

HV Test Equipment Articles