| 摘要 |
PROBLEM TO BE SOLVED: To prevent a dangerous failure from being generated by an excessive surge with a simple structure, in a three-phase earth leakage breaker performing breaking operation by surely detecting leakage even if either one of three phases is interrupted. SOLUTION: An interruption control means 3 to output an interruption signal by detecting a leakage current by a zero-phase current transformer 2 through which three power lines 1 of a three-phase electric circuit are inserted receives a supply of power by three power supply lines 10 connected to the respective three power lines 1, and one side ends of three star-connected surge absorbing elements 6 are each connected to the power supply lines 10. Either one of lines 11 of the star-connected surge-absorbing elements 6 is inserted in the zero-phase current transformer 2. COPYRIGHT: (C)2006,JPO&NCIPI
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