| 摘要 |
<p>PURPOSE:To enable maintenance inspection operation such as exchange of parts at a circuit breaker portion of an auxiliary switch to be reduced drastically by allowing a current source current to flow to only a series circuit of a circuit breaker under test and an auxiliary circuit breaker without flowing to the auxiliary switch. CONSTITUTION:A current source current 1c allows current to flow to only a circuit breaker 1 under test and an auxiliary circuit breaker 5 and a small short-circuiting current ia which is at least approximately 1/10-1/100 of the current source current ic is supplied to an auxiliary switch 6 from another power supply. Furthermore, a current superposition circuit consisting of a capacitor 9 which is precharged, a control gap 8, and a resistor is provided at a circuit side of the short-circuiting small current ia, thus enabling a phase difference of zero point of a current source current ic and the short-circuiting small current ia near a current-breaking zero point which is generated due to arc voltage, etc., generated according to circuit conditions and the circuit breaker and the short-circuiting small current ia to be controlled. No current source current ic is allowed to flow to the switch 6 and a small amount of current for maintaining an arc of the switch 6 is simply broken, thus preventing damage due to the arc at the circuit-breaking portion and eliminating a need for maintenance inspection such as exchange of parts at the circuit-breaking portion.</p> |
