The effect of contact opening velocity and the moment of contact opening on the AC erosion of Ag/CdO contacts

Author

McBride, J.W. ; Sharkh, S.M.A.

Author_Institution

Dept. of Electr. Eng., Southampton Univ., UK

Volume

17

Issue

1

fYear

1994

fDate

3/1/1994 12:00:00 AM

Firstpage

2

Lastpage

7

Abstract

This paper presents experimental results on the influence of contact opening velocity and the moment of contact opening with respect to the start of the AC current cycle on arc energy and contact erosion when breaking an AC resistive circuit. The test currents are 5.6 A, 14.7 A, and 26.3 A, and the contact material is Ag/CdO (90/10). A computer controlled test system allows the control of the contact velocity profiles with constant velocities up to 0.8 m/s and also enables the synchronization of the contact opening with a point on the AC current waveform. Contact erosion is evaluated by measuring the mass changes of the cathode and anode. The results show that increasing the contact velocity from 0.1 m/s to 0.8 m/s leads to an increase in the arc energy. The material transfer from one electrode to another is shown to depend on the current, the polarity of the moving contact, the moment of the contact opening with respect to the start of the AC current cycle, and the opening velocity of the contacts

Keywords

automatic testing; cadmium compounds; circuit-breaking arcs; electrical contacts; life testing; silver; wear testing; 0.1 to 0.8 m/s; 5.6 to 26.3 A; AC erosion; AC resistive circuit; Ag/CdO contacts; AgCdO; arc energy; computer controlled test system; contact erosion; contact opening velocity; material transfer; synchronization; Anodes; Cathodes; Circuit testing; Contacts; Control systems; Electrodes; Physics; Surface resistance; System testing; Velocity control;

fLanguage

English

Journal_Title

Components, Packaging, and Manufacturing Technology, Part A, IEEE Transactions on

Publisher

ieee

ISSN

1070-9886

Type

jour

DOI

10.1109/95.296361

Filename

296361