Title :
The effect of various silver tin oxide materials on contact performance under motor load (a.c.)
Author :
Francisco, Hugo Alberto ; Myers, Michael
Author_Institution :
Deringer Mfg. Co., Mundelein, IL, USA
Abstract :
The new contact material AgSnO/sub 2/ which is replacing AgCdO in many applications, requires the addition of additives to improve electrical contact performance. These additives such as copper oxide (Cu/sub 2/O) and bismuth oxide (Bi/sub 2/O/sub 3/), can significantly affect contact performance. An investigation was undertaken to compare the changes in contact performance between silver cadmium oxide (internally oxidized) and three silver tin oxide based materials containing (1) no additive, (2) copper additive and (3) bismuth plus copper additives. Performance changes and physical characteristics of each material such as formability (tensile properties), contact resistance and contact material erosion (arc erosion) were evaluated. The silver tin oxide based materials containing copper additive exhibited significantly higher resistance to arc erosion than silver cadmium oxide based material and other silver tin oxide materials evaluated. The resistance to welding and changes in electrical resistance were dependent on the chemistry of each material. The results suggested that the chemistry of the material was the chief reason silver tin oxide based material with copper additive performed better than silver cadmium oxide based material under identical motor load.
Keywords :
AC motors; contact resistance; electrical contacts; silver compounds; tin compounds; AC motor load; AgCdO; AgSnO/sub 2/; AgSnO/sub 2/:Cu/sub 2/O; AgSnO/sub 2/:Cu/sub 2/O,Bi/sub 2/O/sub 3/; additive; arc erosion; chemistry; contact resistance; electrical contact; formability; internal oxidation; silver tin oxide material; tensile properties; welding; Additives; Bismuth; Cadmium compounds; Chemistry; Contact resistance; Copper; Electric resistance; Silver; Tin; Welding;
Conference_Titel :
Electrical Contacts, 1997., Proceedings of the Forty-Third IEEE Holm Conference on
Conference_Location :
Philadelphia, PA, USA
Print_ISBN :
0-7803-3968-1
DOI :
10.1109/HOLM.1997.638050