Blow-open forces on double-break contacts

Author

Shea, John J. ; DeVault, Birch ; Chien, Yun-Ko

Author_Institution

T&Q Center, Eaton Cutler-Hammer Corp., Pittsburgh, PA, USA

Volume

17

Issue

1

fYear

1994

fDate

3/1/1994 12:00:00 AM

Firstpage

32

Lastpage

38

Abstract

Measurements were made on double-break contact geometries, commonly used in power distribution devices, to determine contact dynamics under various short circuit fault conditions. These measurements lead to a modification to improve contact dynamics during a short circuit. The modification consisted of a guide rod that prevented contact arm rotation during arcing. Contact dynamics depended on two blow-open forces, magnetic repulsion and gas pressure. Both forces were quantified for various double-break contact geometries along with arc voltage and contact travel. The gas pressure, created by arc energy, was found to be a significant blow-open force. Measured blow-open forces were compared to a sealed piston model to obtain an empirical equation for blow-open forces. Contact performance was also determined with and without the guide rod for a range of arc currents

Keywords

circuit-breaking arcs; contactors; electrical contacts; switchgear testing; arc currents; arc voltage; blow-open forces; contact dynamics; contact geometries; contact travel; double-break contacts; gas pressure; guide rod; magnetic repulsion; power distribution devices; sealed piston model; short circuit fault conditions; Circuit faults; Contacts; Force measurement; Geometry; Magnetic separation; Pistons; Plasma measurements; Plasma temperature; Springs; Voltage;

fLanguage

English

Journal_Title

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

Publisher

ieee

ISSN

1070-9886

Type

jour

DOI

10.1109/95.296365

Filename

296365