Force in the Arc

The total forces integrated along the arc length and contact opening
velocities are shown in Figure 7.4. The results show no simple trend with contact
opening velocity. However, the data are compatible with an approximately constant
total force.
The results of the magnetic forces modeling here are lower than the modeling results
of Paul [11] who considered the magnetic driving force in the contact region from the
magnetic field from the conductors and steel plates in the side walls. The magnetic
flux density (B) was 31 mT/kA for the conductors in the air with a gap of 10 mm.
Thus, at an arc current 2000 A, the magnetic forces was about 1.24 N.
The arc chamber geometry is considered. The magnetic flux density calculation here
is considered at the point that the arc root moves from the contact region with contact
opening velocities.

 

Reference:Arc Control in Circuit Breakers: Low Contact Velocity