To provide an electronic breaker that trips a main contact using an electronic overcurrent tripping device instead of using a mechanical overcurrent trapping device when a short circuit occurs in a high-impedance circuit.
A diode 15 rectifies an AC voltage taken out from an electric path 4 and a capacitor 16 smoothes the rectified voltage. A power circuit 8 steps down a DC voltage from the capacitor 16 and supplies the voltage to a CPU 7 as an operating voltage. When an electric path voltage falls because a modest amount of short-circuit current flowed via a distribution line or load device impedance, the CPU 7 operates on a discharge voltage of the capacitor 16 and checks the short-circuit current that flows to the electric path 4. When the short-circuit current exceeds a reference value set smaller than an operating current value of a mechanical overcurrent tripping device 3, the CPU 7 outputs a trip command to an electronic overcurrent tripping device 2 and trips a main contact 5 with a trip coil 9.
JP2009170338A | 2009-07-30 | |||
JP2009163882A | 2009-07-23 | |||
JP2009170338A | 2009-07-30 | |||
JP2009163882A | 2009-07-23 | |||
JPH01307132A | 1989-12-12 | |||
JPH0432121A | 1992-02-04 | |||
JPH04123740A | 1992-04-23 | |||
JPH07326273A | 1995-12-12 | |||
JPH07211217A | 1995-08-11 | |||
JP2005183226A | 2005-07-07 |
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