Monitoring Of Fuses, Circuit Breakers and Busbars Using PLC

Abstract

Review of previous research and practical experience indicate the importance of monitoring parameters of electric components and technical and economical advantages of programmable logic controllers (PLC's) over other monitoring devices.

An experimental study is reported for use of PLC's in monitoring temperatur-e rise of terminal contacts as one of failure modes.

The results are used as the basis of suggested mathematical equations for-the relation between temperature rise and time.

A cost/benefit analysis is performed for assessment of the importance of monitoring. Results indicate several remarks and conclusions. No single technique whether on line or off-line, continuous or periodic will cover all failure causes. These techniques for monitoring give a qualitative analysis, not a quantitative analysis. On-line monitoring techniques can provide valuable information regarding the performance of a breaker. Data analysis performed by qualified personnel is still required in order to determine the action plan resulting from the monitoring results. This can be minimized if an expert system is incorporated. Monitoring systems require a careful observation period to ensure the system is setup and responding appropriately. The greatest numbers of failures originate in the operating mechanism, so it is the place to start with monitoring.