Arcing voltage for a medium-voltage air load break switch

Air is an environmentally benign and attractive
alternative to SF₆ as arc quenching gas in switching devices for
modest current and voltage ratings. Several interruption tests
with a simple air medium-voltage load break test switch have
been carried out to investigate the arc and the arcing voltage
behavior for different circuit and switch design parameters.
During the first half-cycle after contact separation, the arc voltage
is typically 100 – 200 V. Approximately 50 μs before current
zero the arc voltage increases in magnitude, before collapsing at
current zero. The arc voltage increases with increasing contact
gap, with decreasing current, and with increasing air flow. The
arc voltage measurements from this work are believed to be
suitable as experimental reference for verifying results from
computational current interruption models.