摘要 |
A modification of the squirrel cage of an alternating current motor reduces the starting current amperage. A conventional motor squirrel cage, which includes rotor bars and shorting rings, is modified so that the cage may have two or more controllable resistance values by segmenting the shorting rings. A high resistance cage is obtained for initial motor starting when the open segmented shorting rings provide a high resistance path within the squirrel cage circuit. Subsequent to the motor's attaining full rotation speed, a low resistance value of the squirrel cage is achieved by shunting the segmented shorting rings, which gives the motor its optimum running efficiency. In one embodiment, a mechanical means is used to accomplish the shunting of the shorting rings. In a second embodiment, a solid state control device is used to accomplish the shunting of the shorting rings.
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