New sensing techniques used in Circuit Breaker diagnosis

In the paper new sensing techniques have been presented that are applied in Circuit Breaker diagnosis. The techniques employ remote temperature measurement and emission spectrum detection. They are used for CB contacts evaluation. A thermal reference of the contacts working in closing and opening mode has been developed through simulation of CB contacts thermal model and verification with real measurement values for various contact materials. The reference is compared with actual temperature measurement values of working contacts. Temperature measurements are carried out remotely with the use of specially developed selective detectors. The second of the new CB diagnostic methods uses spectral emission analysis and detection of special spectral lines during contact breaking. The contact is composed of two layers made from different materials. Subsequent closures and openings expose the base layer so that emission lines that characterize the material in the base layer appear in the emission spectrum.