| 摘要 |
PURPOSE: To control the complete power failure by a compact, simple installation by actuating a branch circuit breaker when a current flowing through a cable way has an external predetermined level lower than the predetermined level. CONSTITUTION: Control means 5 judges whether a current value of the currents detected' by current detecting means 1 is greater than the rated interrupting current; if it exceeds the rated interrupting current, an external detecting section 13 determines a delay time for that current value based on the external predetermined level; and if the current value continues beyond the delay time, then an external overcurrent signal is output. An external trip signal output section 16 inputs said external overcurrent signal and outputs an external trip signal so as to actuate a branch breaker B having an earlier priority order in accordance with the priority order set by priority order setting means 4. External switching drive means 23 sends an external trip signal to a corresponding branch breaker B based on said external trip signal for interruption. By doing this, a complete power failure can be restricted by said compact, simple installation. |
