To provide an earth leakage circuit breaker capable of avoiding an unnecessary breaking operation while securing human body protection against earth leakage.
An earth leakage circuit breaker comprises: a current transformer 12 having a magnetic core 12b surrounding a conductor 2 and a secondary wiring 12a wound around the magnetic core 12b; an excitation circuit 13 which supplies excitation current to the secondary wiring 12a; a measurement signal detection circuit 14 which detects a measurement signal including leakage current in the conductor 2 from the excitation current; a separation circuit which separates the measurement signal into a dc component and an ac component; a rated sensitivity setting unit 27 for dc; a rated sensitivity setting unit for ac; a circuit breaker 1 which can break the conductor 2; and a breaking control unit. The breaking control unit breaks the conductor with the circuit breaker when the dc and ac components of the measurement signal separated by the separation circuit exceed the dc and ac rated sensitivity current values set by the rated sensitivity setting units for dc and ac.
HOSOOKA YOHEI
HASHIMOTO TAKASHI
NODERA TOSHIO
| JP2004227809A | 2004-08-12 | |||
| JP2005065382A | 2005-03-10 | |||
| JPS55148320U | 1980-10-25 | |||
| JP2000102158A | 2000-04-07 |
Hide Tanaka Tetsu