Abstract: An alternative gas current pause circuit interrupter with an internally switched resistor-varistor impedance. The varistor limits the voltage rise across the main contactor limiting restrikes, while the resistor limits the current through the interrupter. The values of the resistor and varistor are selected to creates a current pause in the current. In a representative embodiment, the current pause performance is less than 10% of the rated line current for at least 15% of the half-cycle period allowing a plain break butt impedance contactor to be utilized without excessive arcing. For another embodiment the current pause performance is less than 5% of the rated line current for at least 20% of the half-cycle period. SF6 free alternative gas current pause circuit interrupters using a 60% CO2 blend can achieve similar or improved transient voltage performance compared to similarly sized conventional SF6 gas interrupters operating at the same voltage rating.

Abstract: An alternative gas current pause circuit interrupter with an internally switched resistor-varistor impedance. The varistor limits the voltage rise across the main contactor limiting restrikes, while the resistor limits the current through the interrupter. The values of the resistor and varistor are selected to creates a current pause in the current. In a representative embodiment, the current pause performance is less than 10% of the rated line current for at least 15% of the half-cycle period allowing a plain break butt impedance contactor to be utilized without excessive arcing. For another embodiment the current pause performance is less than 5% of the rated line current for at least 20% of the half-cycle period. SF6 free alternative gas current pause circuit interrupters using a 60% CO2 blend can achieve similar or improved transient voltage performance compared to similarly sized conventional SF6 gas interrupters operating at the same voltage rating.