The effect of contact gap

The effect of contact gap

The arc starts to move off from the contact region
when the contact gap is less than previously
thought [35].

The arc current is dependant on the
contact opening velocity. The anode root velocity on
the moving contact is more than the cathode root on
the fixed contact. The total mass flow decreases as
the contact opening velocity is increased. There are
more electronegative elements more at high contact
opening velocities than at lower velocities.

This research suggests that low contact velocity
MCBs can gain the same performance of the arc root
motion from the contact region as fast contact
opening. It also makes the use of smart material
actuation possible in these devices.

Reference:

-Ronsek Ltd
-Pechrach Publishing
Slow Contact Opening Circuit Breakers