Vibration analysis for diagnostic testing of circuit-breakers

In order to assess the feasibility of vibration analysis for diagnostic 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 analyzed. The breakers were assumed to be in good condihn with no known irregularities at the time of testing. However, several serious faults, including an incipient rupture of the contact plug shaft, an incorrectly assembled crank, and major lubrication problems were disclosed. Thus, this "blind test" performed under realistic conditions on circuit-breakers in normal service demonstraites that vibration analysis can be a reliable and suitable tool for non-invasive diagnostic testing.