Computer Controlled Testing and Evaluation of Contact Materials in Three-Phase AC Devices

The study of electrical arc erosion that takes place on contact material plays an important part in evaluating the performance of an electrical switching device. Arc erosion studies can also be used to determine the type and quality of a contact tip alloy used in a particular switching device. Many variables are encountered on actual production contactors. These variables can affect the erosion rate of a contact material adversely. A contact material that performs exceedingly well in one type of device may perform poorly when installed in a different device even though the electrical ratings are identical and the testing parameters are carefully controlled. Arc erosion taking place on actual production devices which are operated side by side 24 h a day in a computer operated test cell, the parameters of which are closely controlled to meet the recommendations of the International Eiectrotechnical Commission (IEC) specified in Publication 158-1, is investigated and studied. The synthetic load networks and methods by which erosion data is obtained are discussed.