A “Universal” life-test system for electromechanical relays

The field of Electrical Contact Switching brings together physics, material technology and accumulated experience and remains a very analogue science. Real-world monitoring of contact switching is vital in determining the best materials and construction for a relay device and to ensure quality in today's demanding market place. Although it is simple in principle to cycle a relay with a specific contact load and observe total failure, designers today require much more insight into trends allowing them to better predict failures in contact use, in application areas that have not been fully tested. Applied Relay Testing has been performing research and development into a `universal life test system' which would provide information about contact voltage and current, contact timing and device operate / release voltage actually DURING the lifetest, showing each of these parameters in a graphical form and allowing their trends to be observed. This paper will describe the measurement techniques involved and the results obtained, illustrating how this test system brings a unique insight into the life-time of the modern electromechanical relay.