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| Figure 9-4 Solenoid-operated mechanism. |

| Solenoid type. This type of mechanism consists of a powerful closing coil, a relatively small trip coil, a latching device, an auxiliary switch and system of levers, and links and toggles for multiplying the short stroke of the closing coil armature (Fig. 9-4). The breaker is closed by energizing the solenoid so that it pulls the breaker rod upward and closes the contacts; at the same time, it may also compress a spring. The breaker (and spring, if so equipped) is latched in this position and the solenoid de-energized by means of the auxiliary switch. Opening is accomplished by energizing the small trip coil so that it releases the breaker contacts; these open through the action of gravity, or a spring, or both. Solenoids may be operated either on ac or dc. |

| Motor type. Motor operated mechanisms are usually of two types. One type utilizes the principle of centrifugal force (Fig. 9-5). The motor revolves two fly-weights at high speed, and the centrifugal force thus devel- |

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