Current zero measurement for circuit breaking phenomena

This paper describes a new measuring method of the current zero phenomena of the circuit breaker with use of vacuum interrupter connected in parallel to the high resistance coaxial shunt. This method is applicable for the test circuit up to 50kA. The process is less effected by the electromagnetic induction offering a much accurate results. The measurements are conducted to obtain the V-A relation around current zero region of model SF6circuit breakers. The investigations on the transient time of the arc resistance, arc time constant and arc energy show that the arc time constant cannot be treated as a constant as the Mayr´s equation is dealt.