| 摘要 |
<p>PROBLEM TO BE SOLVED: To inform a controller of the tripped state of an MMR breaker not through a direct line but through a field bus. SOLUTION: Each MMR connected to a controller and a field bus 14 comprises an MMR breaker 1 and a control circuit 4, a motor 15 is connected to a power line 10 through the breaker 1 and started/stopped by a contactor 8. At the time of receiving a start command from the field bus 14, a CPU 4b outputs a command from a DO 4d, closes a contact 6 and excites a relay 7 to input the contactor 8. Then, the CPU 4B fetches the state of equipment to be driven by the motor 15 by using a limit switch 5 through an DI 4c and transmits the fetched state to the field bus 14 together with an existence signal. Although communication abnormality occurs due to the off of power supply when the breaker 1 is turned off, the operation of the control circuit 4 can be temporarily main-tained by a substitutive power supply 3a. Since a charging position detection switch 3b is closed when the breaker 1 is tripped, the CPU 4b discriminates the tripped state and transmits a trip detection signal to the bus 14.</p> |
