Safe and quick high voltage circuit breaker testing using DCM dual ground technology

Safety is one of utmost important factors during testing, commissioning and maintenance of HV equipment. Especially for high voltage circuit breakers, regulation requires that both sides of a circuit breaker to be grounded during testing. Timing test, is one of most important tests for HV circuit breaker, traditionally was not possible using dual ground method since open and close cannot be sensed as it is always shorted by ground loop. This puts testing personnel to danger and requires additional safety steps which also increase testing time. DRM method was developed 15 years ago which made it possible on some outdoor HV breakers. However, DRM had lot of limitations which simply was not possible in some instances like GIS switchgear. As a result, DCM resonance method was developed and patented to solve these issues. This paper, will discusses how DCM method works and what benefits it provides to safety and testing time. This paper also discussed the benefits DCM method provides over older DRM method.