Averting Failure of Pre-Insertion Resistor in Circuit Breaker Through Preventive Maintenance

Abstract

Pre-insertion resistor (PIR) is an important component of circuit breaker. The healthiness of the circuit breaker (CB) depends upon that of PIR contact. With the increasing demand of uninterrupted power supply, failure in major equipment like CB may incur huge loss to the utility. The existing study reveals that mechanical failures are more dominant than other types of failures. Thus, many industries prefer to undertake preventive maintenance of equipment rather than break down maintenance. This paper describes the actual problem detected in PIR contact of North Eastern Regional Transmission System, having a 400 kV, 3000 A, SF6 CB through testing and rectification thereafter. The results obtained from the graph helped in detecting mechanical dis-alignment of the connecting link in the link arm and the tubular contact of the PIR. Furthermore, a model has been developed to show the possible threat that would have occurred, had the problem been not rectified. This paper will help the utilities to emphasize on detecting the problem by undergoing preventive maintenance and thereby saving unprecedented failure of equipment.