| 摘要 |
PURPOSE:To enable to use a cam switch adapted only for starting and varying the secondary side resistance of a wound-rotor induction motor by driving an electromagnetic switch by the cam switch and shortcircuiting the secondary side with the contact of the switch. CONSTITUTION:Resistors 6g-6a, 6h-6b, 6i-6c are respectively connected to the secondary sides U, V, W of a wound-rotor induction motor 1, shortcircuited by closing cam switches 5a-5d with a cam formed on a cam shaft of an automatic starter, thereby smoothly accelerating the motor 1. An electromagnetic switch 9 which is driven by a cam switch 8 is provided, and the secondary terminals U, V, W are shortcircuited by the contacts 9a, 9b. Accordingly, the electromagnetic switch contact in response to the motor capacity can be used as the contact for shortcircuiting the secondary side can be used, and the cam switches 5a-5d adapted only for starting can be used, thereby improving the economy of the device. |
