DocumentCode :
912734
Title :
Effect of an axial magnetic field upon the development of the vacuum arc between opening electric currents [currents read contacts]
Author :
Schulman, M.B. ; Slade, Paul G. ; Heberlein, J.V.R.
Author_Institution :
Westinghouse Sci. & Technol. Center, Pittsburgh, PA, USA
Volume :
16
Issue :
2
fYear :
1993
fDate :
3/1/1993 12:00:00 AM
Firstpage :
180
Lastpage :
189
Abstract :
In one series of experiments, a constant axial magnetic field Bax was produced in the gap between opening Bruce-profile, chromium-copper contacts. Peak arc currents up to 40 kA at 50 Hz were studied with Bax u to 112 mT. For each peak current, a critical field Bcrit was determined above which anode spots did not form. For Bax greater than Bcrit, the time from contact parting to the formation of a diffuse vacuum arc was linearly dependent on separation current. In a second series, the contacts were designed to generate a self Bax when AC current up to 123 kA peak flowed. This field was approximately proportional to the current waveform through the contacts, and it was always higher than the B crit predicted for the instantaneous current. The time from contact parting to the formation of the diffuse arc was consistent with that observed in the first experimental series. Once the diffuse arc had formed, the contacts showed no distributed melting for currents up to 81 kA, but gross melting occurred at 102-123 kA. The formation of diffuse arcs is discussed, and the anode melting is explained
Keywords :
chromium; circuit-breaking arcs; copper; electrical contacts; magnetic field effects; 0 to 112 mT; 15 to 200 kA; 50 Hz; Cr-Cu contact; anode melting; axial magnetic field; critical field; current waveform; diffuse arc; gross melting; opening Bruce profile contact; peak arc current; vacuum arc; Anodes; Cathodes; Circuits; Coils; Contacts; Interrupters; Magnetic confinement; Magnetic separation; Vacuum arcs; Voltage;
fLanguage :
English
Journal_Title :
Components, Hybrids, and Manufacturing Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
0148-6411
Type :
jour
DOI :
10.1109/33.219403
Filename :
219403
Link To Document :
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