Abstract :
Any switching arc can interrupt dc currents when the open circuit voltage is less that the minimum arc voltage (about 15 V). In the electrochemical industry most cells operate at about 5 V. The development of bipolar diaphragm cells for the chlor-alkali industry created a need for a 50-V shorting switch. To fill this need, a unique arcing contact was designed, tested, and incorporated in a shorting switch that has routinely interrupted 75 kA at about 50 V since 1980. Equations are derived and supported by laboratory and field test data.