| 摘要 |
PURPOSE:To accurately detect an overload by obtaining the vector difference between the input currents of hysteresis motors and the average input currents of the motors. CONSTITUTION:A current transformer 4 obtains the total value of the currents input to hysteresis motors 1a-1n from the current flowed to a master input wirings, obtains the average value of the input currents flowed to the motors 1a-1n by dividing the voltage, and current transformers 5a-5n individually detect the input currents input to the motors 1a-1n. Measuring instruments 6a- 6n provided corresponding to the motors 1a-1n obtain the difference between the output from the transformer 4 and the output from the transformers 5a-5n, thereby detecting the overload of the motors 1a-1n. |
