VIBRATION ANALYSIS FOR DIAGNOSTIC TESTING OF CIRCUIT-BREAKERS

In order to assess the feasibility of vibration analysis for diagnosti c testing of high-voltage circuit-breakers a comprehensive field test program has been carried out. Vibration patterns from 31 breakers (93 identical single-phase units) have been acquired, compared and analyze d. The breakers were assumed to be in good condition with no known irr egularities at the time of testing. However, several serious faults, i ncluding an incipient rupture of the contact plug shaft, an incorrectl y assembled crank, and major lubrication problems were disclosed. Thus , this ''blind test'' performed under realistic conditions on circuit- breakers in normal service demonstrates that vibration analysis can be a reliable and suitable tool for non-invasive diagnostic testing.