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Page 142

| Figure 8-12 Bayonet contact. |

| Bayonet Contacts |

| Bayonet contacts (Fig. 8-12) consist of a rod (the moving contact) that fits into a sheath (the stationary contact). The sheath stationary contact usually consists of one or more spring sleeves into which the moving contact rod is forced. It is also sometimes constructed so that a butt contact is made between the end of the rod and the bottom of the sheath. Bayonet contacts usually have arcing contacts, which may consist of another auxiliary set of contacts that extend to one side of both movable and stationary contacts. These open after the main contacts open, and the arc forms between them. |

| Arc Control |

| The interrupting ability of a circuit breaker depends a great deal on how quickly the arc can be extinguished and the circuit opened. Several means are employed, including the chutes previously described for air circuit breakers. The capacity of oil circuit breakers may be increased by employing auxiliary devices that tend to confine arcs already formed and can thus extinguish them more rapidly. |

| Explosion Chambers.. |

| Explosion chambersessentially cylinders that surround any arc taking placeserve to create higher pressures for the gases generated (Fig. 8-13). These higher pressures, confined to a degree within the explosion chamber, not only tend to smother the arc but materially increase the opening speed of the breaker interrupting the circuit. |

| De-ion Arc Quencher |

| Another device, the de-ion arc quencher, confines, divides and extinguishes arcs much more rapidly when a circuit is broken. In this device, the |

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