| 摘要 |
A current limiter unit employs both a magnetic repulsion field and a gas pressure force to direct arcs to within the high voltage region of an arc chute. The unit confines the evolved gas pressure in all directions except in the direction of the arc plates. Venting the opposite end of the arc chute rapidly motivates the arc through the arc plates and out of the unit. Venting the sides of the arc chute reduces the back pressure produced by arc gases as well as the pressure exerted upon the heated breaker casing. The combination of magnetic and directed gas repulsion substantilly reduces the I2t value of the unit. A parallel positive temperature coefficient impedance can be connected across the arc to reduce the arc current to a low enough value so that the arc becomes extinguished within a predetermined period of time.
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