JPS5582304A - Monitor unit for sequence delay preventive maintenance - Google Patents

Abstract

PURPOSE:To make it possible to detect previously a forecasted sequence delay by monitoring whether a stop circuit is normal or not and whether a start circuit is normal or not in the operation time and the stop time respectively at a fixed period. CONSTITUTION:Assuming that an output command is given to a sequence controller, for example, in a water-wheel generator, an entrance valve start command is issued under interlock conditions A-D satisfied. Next, when feedback condition G indicating that the entrance valve opens fully is returned, a start command is issued under this condition G and interlock conditions E and F satisfied. Assuming that the generator stops, interlock conditions of a start circuit are checked for normalcy at every fixed period by a program, and a condition indicator lamp and an operation state indicator lamp are lit on a display equipment to issue alarm if conditions are not satisfied. Interlock conditions of a stop circuit are checked at every fixed period in the operation time of the generator also. As a result, preventive maintenance for sequence delay can be performed.