| 摘要 |
<p>Disclosed is a circuit breaker comprising an interruptor including a main contact and a series circuit connected in parallel to the main contact and constituted by a breaking resistor and a resistor contact; and an actuator device for performing closing to opening operations of the main contact and the resistor contact; in which the breaking resistor includes a first resistor element and a second resistor element having a resistance value which is smaller than that of the first resistor element; and in which a switching circuit is provided for automatically changing the connection of the first and second resistor elements such that in small capacitive current breaking, an equivalent resistance of the first and second resistor element becomes a large value suitable for the small current breaking, while in short-circuit current breaking, the resultant equivalent resistance becomes a small value for the short-circuit current breaking mainly owing to the resistance value of said second resistor element.</p> |
