Electrical Contacts Condition Diagnostics Based on Wireless Temperature Monitoring of Energized Equipment

Continuous exposure of electrical contact to elevated temperatures contributes to the downgrading of contact quality. Gradual degradation of contact surfaces induces developing conduction problems resulting in local temperature rise. The paper presents industrial case studies of continuous temperature monitoring of electrical contacts in energized equipment using wireless system with miniature temperature sensors. Wireless technology for on-line condition monitoring is applicable both as standalone system and with an interface with power quality monitoring system. Continuous on-line temperature monitoring combined with detail analysis of thermal contact behavior in correlation with the load current provides the means to evaluate physical condition of electrical contacts and detect abnormality. Practical applications of wireless temperature monitoring technique demonstrate its importance for properly and timely performed condition-based maintenance preventing possible disruption of electrical service. Observational data collected for several years of continuous contact temperature monitoring may be used for development of diagnostic and prognostic algorithms applicable for maintenance scheduling and better assets management.