PROTECTIVE DEVICE FOR POWER DISTRIBUTION BOARD

摘要

PROBLEM TO BE SOLVED: To achieve protection coordination by clearly separating a protective area so that when an electrical accident arises in a power distribution demanding circuit system branching from and connected to a power system via a power incoming device that branches and connects a demanding circuit system, the protective circuit of the power distribution demanding circuit system operates first.SOLUTION: A power distribution board 1 is provided between a power distribution demanding circuit system 10 and a master power incoming device 8, the power distribution demanding circuit system 10 is branching from and connected to the master power incoming device 8 provided between a master demanding circuit system 80 and a power system 50 and having a master shutoff device 9. The power distribution board 1 has, as a protective device: an electric leak blocking device 3 that is able to block a power supply path according to a current based on an electric leak event or overload event caused in the power distribution demanding circuit system 10; and a short-circuit blocking device 5 that is connected in series to the electric leak blocking device 3 and is able to block a power supply path according to current based on a short-circuit event caused in the power distribution demanding circuit system 10. The short-circuit blocking device 5 is configured to block the power supply path in a shorter time than the master shut-off device 9.