| 摘要 |
PURPOSE:To energy-save a motor switching to reduce the number of poles in a high rotating speed range and to increase the number of poles in a low rotating speed, thereby enhancing the operating efficiency. CONSTITUTION:Relay contacts X1, X3 are closed in a high rotating speed range to the 1/2 speed of the maximum speed, an induction motor 8 is formed in a double star type circuit by opening a relay contact X2 to use the motor 8 as a 2-pole motor. In the low rotating speed range from the 1/2 speed of the maximum speed, the relay contacts X1, X3 are opened to form a star type connection in which the relay contact X2 is closed to use the motor 8 as a 4-pole motor. |
