Monitoring of primary circuit temperatures and breaker condition in a substation

Different temperature-related fail-mechanisms in switchgear are discussed. A new high potential temperature monitoring system is presented. The new system can give early warnings of beginning fail-mechanisms, and can also be used to allow intentional short-period overloading. Relevant alarm criteria are analysed. Field tests where temperature data were sent on telephone lines are described. Different parameters, relevant for monitoring of circuit breaker condition are discussed. Improved versions of the condition monitor for the HPA-breaker, presented in a CIRED-report 1985, are presented. The possibility to integrate temperature monitoring, breaker monitoring and other monitoring units into a flexible data communication system is discussed