| 摘要 |
PURPOSE:To facilitate countermeasure to electrical noise and adjusting work by providing a plurality of input boards and a main relay board, operating the input signal from bus side digitally and transmitting to the main relay board for the purpose of data processing. CONSTITUTION:A protective relay comprises a main relay board 200 and a plurality of input boards 101, 102,... connected therewith. Auxiliary contacts ALS1, ALS2 indicating the states of an auxiliary current transformer ACT and disconnectors LS1, LS2 are arranged in the input detection unit 101A of the input board 101. A data processing unit 101B comprises an analog filter AF, an A/D converter A/D, a microprocessor MPU1 and the like, and transmits data to the main relay board 200. The main relay board 200 comprises a plurality of microprocessors MPU2 and the like, and produces a trip signal for a circuit breaker. Consequently, countermeasure against noise can be taken advantageously and the length of wiring in the board can be shortened. |
