| 摘要 |
PURPOSE:To simplify the maintenance and checking and also to improve the reliability of a device protector by setting a checking program into a program controller in addition to a device control program and executing said checking program for every fixed period. CONSTITUTION:The checking cycle time is intergrated by a program set into a program controller 8, and the intergation time is reset to 0 when a fixed period of time elapses. At the same time, the program of the controller 8 is switched to a checking program for a device protector 4. Thus the device 4 is checked. In this case, the elements constituting the device 4 are first selected. That is, a protecting relay 5 is selected and connected to the controller 8. Then a check signal 14 is transmitted from the controller 14 and supplied to a checking circuit to perform a trial working test, a characteristic test, etc. If the results of these test are normal, a normal signal 15 is sent to the controller 8. However the signal 15 is not transmitted to the controller when a fault occurs. Then the controller 8 decides a fault and delivers an alarm via a monitor device 9. |
