Title :
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
fDate :
3/1/1994 12:00:00 AM
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;
Journal_Title :
Components, Packaging, and Manufacturing Technology, Part A, IEEE Transactions on
