Breaker Fire Reverse Polarity

[mbrooke]

Why would reverse polarity do this? What makes a DC breaker need + & -?



https://www.youtube.com/watch?v=Cup5fMGaE2g

 

[SG-1]

Probably for the same reason a switch is sometimes marked. A magnet is used to help extinguish the arc.

 

[mbrooke]

Probably for the same reason a switch is sometimes marked. A magnet is used to help extinguish the arc.

Physics? Anyone have pics of the internals?

 

[GoldDigger]

Physics? Anyone have pics of the internals?

The individual charge carriers in an electric arc immersed in a magnetic field perpendicular to the plane of the arc will be moved by magnetic forces in one direction (perpendicular to both current path and field lines). If that direction is toward an open area (arc chute?) which allows the arc to lengthen and become easier to extinguish, an arc with the opposite current flow will be pushed in the opposite direction (possibly against a supporting surface which will keep the arc from lengthening.)

 

[mbrooke]

The individual charge carriers in an electric arc immersed in a magnetic field perpendicular to the plane of the arc will be moved by magnetic forces in one direction (perpendicular to both current path and field lines). If that direction is toward an open area (arc chute?) which allows the arc to lengthen and become easier to extinguish, an arc with the opposite current flow will be pushed in the opposite direction (possibly against a supporting surface which will keep the arc from lengthening.)

Had not thought about it that way- makes sense.