Relationship Between the Voltage Distribution Ratio and the Post Arc Current in Double-Break Vacuum Circuit Breakers

In many cases, single-break vacuum circuit breakers are used as circuit breakers, and so the characteristics of double-break vacuum circuit breakers have not received sufficient attention. This report describes our investigations of the interruption characteristics of double-break vacuum circuit breakers. We have investigated and clarified the relationship between the voltage distribution ratio and the post arc current in double-break vacuum circuit breakers by measuring the post arc current in the single-break vacuum circuit breaker, the voltage distribution ratio, and the post arc current in double-break vacuum circuit breakers. Our investigation has shown that the post arc current scatter of the spiral contact is much larger than that of the axial magnetic field contact. This result shows that the bias of the voltage distribution ratio was caused by the imbalanced post arc current in each vacuum interrupter in the double-break vacuum circuit breaker. Therefore, we conclude that axial magnetic field contacts are suitable for double-break vacuum circuit breakers.