Title :
Evaluation of AgSnO2 material on high current DC switching
Author_Institution :
Westinghouse Res. & Dev. Center, Pittsburgh, PA, USA
Abstract :
An experimental study was conducted to evaluate the performance of AgSnO/sub 2/ contacts (with 12 wt.% and 15 wt.% of SnO/sub 2/) for high-current DC switching. The contacts were tested in a solenoid-operated fixture equipped with an arc quenching chamber and an in-line magnetic blow-out system. The switching experiment was performed at 480 V DC with currents up to 1500 A. The duty cycle was two operations per minute. Metallurgical analysis of the contact surface and cross section were performed after the tests. A qualitative comparison of the test results to AgWC and AgCdO was made. The Ag-(15 wt.%)SnO/sub 2/ contacts showed better weld resistance than AgCdO and better contact resistance than the AgWC. The Ag-(15 wt.%)SnO/sub 2/ was proved to be a promising candidate for high-current DC switching application. The reduced closing contact bounce significantly improved the contact welding and contact erosion characteristics and greatly relaxed the requirements on contact materials.<>
Keywords :
composite materials; electrical contacts; environmental testing; materials testing; relays; silver alloys; tin compounds; 1.5 kA; 480 V; Ag-SnO/sub 2/ contacts; arc quenching chamber; contact erosion characteristics; contact materials; contact resistance; contact welding; duty cycle; experimental study; high current DC switching; magnetic blow-out system; reduced closing contact bounce; solenoid-operated fixture; switching experiment; weld resistance; Circuit testing; Conducting materials; Contact resistance; Contactors; Fixtures; Materials testing; Performance evaluation; System testing; Voltage; Welding;
Conference_Titel :
Electrical Contacts, 1988., Proceedings of the Thirty Fourth Meeting of the IEEE Holm Conference on
Conference_Location :
San Francisco, CA, USA
DOI :
10.1109/HOLM.1988.16094
