Electricity Today T&D Magazine

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 results indicate an abnormality, the dynamic resistance measurement (DRM) test can be an effective way to further diagnose the internal condition of the breaker contacts. As an example, a high-voltage puffer-type sulfur...