Title :
Influence of the power factor on the degradation of Ag-W electrical contact circuit-breakers
Author :
Furtado, H.C. ; Mocarzel, P.R. ; Silveira, V. L A
Author_Institution :
CEPEL-Centro de Pequisas de Energia Eletrica, Rio de Janeiro, Brazil
Abstract :
Ag-W contacts were evaluated as to their durability by electrical tests, according the IEC 157-1/73, applying different values of power factor. Such contacts were assembled into 30-A single-pole thermomagnetic circuit breakers. The morphology evolution of the arc affected zone was analyzed after 1000, 3000, and 6000 on/off switching cycles with scanning electron microscopy. Based on these results, the contact performances were compared and the influence of the power factor on the degradation of Ag-W contacts of circuit breakers was established.<>
Keywords :
circuit breakers; electrical contacts; power factor; silver; tungsten; Ag-W contacts; IEC 157-1/73; arc affected zone; contact performances; degradation; durability; on/off switching cycles; power factor; scanning electron microscopy; thermomagnetic circuit breakers; Circuit testing; Contacts; Current; Degradation; IEC standards; Reactive power;
Conference_Titel :
Electrical Contacts, 1991. Proceedings of the Thirty-Seventh IEEE Holm Conference on
Conference_Location :
Chicago, IL, USA
Print_ISBN :
0-7803-0231-1
DOI :
10.1109/HOLM.1991.170801
