USCO Power Switches

60

A C C E S S O R I E S

INTERRUPTING DEVICES

Arcing Horns Standard arcing horns are designed to prevent arcing at the main switch contacts. Although they are given no interrupting rating, it is common practice to use these devices to interrupt small values of current such as the charging current of a short length of line or transformer magnetizing current. It should be recognized that the confined electric arc at the switch contacts could cause damage to the switch, and involve adjacent phases, or supporting structure, in the initiation of a major fault. Quick Break Arcing Horns The quick-break arcing horn is a device capable of interrupting a limited amount of line charging or transformer magnetizing current. The whip action, which produces a high-speed contact separation of the stationary and moving horns, limits the length of the arc and extinguishes the arc faster than conventional arcing horns. The interrupting ability of quick break arcing horns is limited, and will vary with atmospheric and operating conditions. Vacuum Interrupter The vacuum interrupter provides confined arc switching (in a vacuum) of load, line charging, and transformer magnetizing currents. The vacuum interrupter is capable of interrupting up to 2000 amperes at voltages 7.5kV through 230kV. At the higher voltages this interrupter utilizes vacuum units in series so interconnected that there is simultaneous separation of the contacts. Units are full voltage rated for interrupting duty up to the full continuous current rating of the main switch, with full open circuit voltage across the interrupter.

SEPTEMBER 2013

HUBBELL / USCO  – LEEDS, ALABAMA USA