| 摘要 |
PROBLEM TO BE SOLVED: To conduct tests continuously for reduction in testing time by identifying a dummy test signal at the time of operational test of an electronic circuit breaker formed so as to incorporate energization heat history properties into overcurrent tripping properties, thereby temporarily releasing the energization heat history properties. SOLUTION: This electronic circuit breaker, involving a controlling part 6 computing a digital signal which is obtained by detecting the current of a wiring route 1 and subjecting it to A/D conversion and, when the current running through the wiring route 1 exceeds rated current, opening a make-break contact 2 with prescribed time limit properties and an energization heat history retaining means for outputting an electric charge pulse meeting the value of the current running through the wiring route 1 from the controlling part 6 to a time constant circuit formed out of a capacitor 8 and a resistor 11 and reflecting the residual voltage of the time constant circuit in the time limit properties, is provided with a switching means 23 bringing the residual voltage of the time constant circuit into zero, when working voltage supplied from the outside of the circuit breaker to the controlling part 6 through a test 12 terminal is detected. |
