Breakers & Relays
Utilizing Fault Resistance to Test Distance Relays
Selecting Substation Medium-Voltage Switchgear: GIS vs. AIS
Breakers & Relays
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 also last up to 10 times the expected lifetime than newer sulfur hexafluoride (SF-6) gas interrupters. Unfortunately, the downside to building a protective device with a long service life is that utility...
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