Zero current circuit interruption
 Each pole of a multi-pole circuit breaker is equipped to individually separate the circuit breaker contacts within each pole upon overcurrent occurrence. A digital processor within the circuit breaker trip unit determines the occurrence of zero current crossing of phase current within the individual poles and initiates contact separation at zero current values. 
General Electric Company
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H01H H01H
additional inventional
Paul H. Raymond K. David
Singer Seymour Arnold