| 摘要 |
An earth leakage breaker is provided to protect a megger test switch body from breakdown by using a cover of a body case which endures an excessive operating force. An earth leakage breaker includes a leakage tripping device, and a megger test switch. The leakage tripping device has a main circuit contact, a switching device, an operation handle, an over-current tripping apparatus, a zero phase current transformer, and a leakage detecting circuit. The megger test switch turns on and turns off a feeding circuit which is installed between the leakage detecting circuit and a main circuit, and separates the leakage detecting circuit from the main circuit by being turned off during an insulating test and a withstand voltage test of the breaker. The megger test switch is installed in a body case of the breaker. A push-and-twist locking type push button(19) which turns on or off the switch body is mounted to a cover of the body case of the breaker. The switch body of the megger test switch is turned off through an actuator(21) by the push-and-twist operation of the push button. The breaker is tripped by driving a trip crossbar(15) to a latch released position.
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