| 摘要 |
PURPOSE:To effective utilize the high velocity of a thyristor switch for accidents within the system during inspection while checking the lock of the trip circuit concurrently by making the entire trip circuit up of thyristor switches. CONSTITUTION:A relay 11X permits starting of inspection by a contact a while a inspection work checking relay R is out of action, while the inspection can be checked by the action of the relay RX during the inspection. The open-circuit of a normally closed contact 11b on the relay 11X is equivalently closed with a thyristor SCR3 turned on. A series circuit comprising a coil TC adapted to trip the breaker and thyristors SCR1 and SCR2 which is turned on by a trip signal from a protection relays RY-A and RY-B can be inspected because its tripping is free from the opening of the contact 11Xb and turning off of the thyristor SCR3. Monitoring the signal b of the normally closed contact 11Xb on the relay 11X allows one to ascertain that it is in a open state (during inspection). |
