Patent ID: 7741937
Filing Date: 2010-06-22
Classification: H01H

Abstract:
1. A power switching apparatus comprising: a breaker unit that is connected on a three-phase current line between a load circuit and a power-supply circuit that supplies driving power to the load circuit, the breaker unit including an operating unit that is configured to simultaneously turn the switches on or off; a measuring unit that measures a current flowing in each phase of the three-phase current line at a point between the power-supply circuit and the breaker unit, and determines a time point at which a current flowing in an arbitrary one of the phases of the three-phase current line becomes zero as a reference time point; and a controlling unit that controls, upon interrupting load current including a small capacitive current, the operating unit to turn off the switches during a time period from the reference time point corresponding to a range from 20 degrees to 40 degrees of an electric angle.