(1) 启动过程：首先选择一台电动机在软启动器拖动下按所选定的启动方式逐渐提升输出电压，达到工频电压后，旁路接触器接通。然后，软启动器从该回路中切除，去启动下一台电机。 (2) 停止过程：先启动软启动器与旁路接触器并联运行，然后切除旁路，最后软启动器按所选定的停车方式逐渐降低输出电压直到停止。 5 应用效果 通过一年的运行，表明该装置可靠性高，性能完善，能满足生产要求。主要体现在以下几点： (1) 使用软启动器后，启动电流明显降低，减少配电容量与增容投资。 (2) 软启动器实现平稳启动，对水泵及管道无冲击，提高供电可靠性和供水可靠性。 (3) 采用软停车方式减少对机械的冲击，防止水锤效应，延长水泵及其相关设备的使用寿命。 (4) 多种启动模式及保护功能融于一体，防止事故的产生。 软起动可减小电动机硬起动（即直接起动）引起的电网电压降，使之不影响共网其它电气设备的正常运行，可减小电动机的冲击电流，冲击电流会造成电动机局部温升过大，降低电动机寿命，可减小硬起动带来的机械冲力，冲力加速所传动机械（轴、啮合齿轮等）的磨损，减少电磁干扰，冲击电流会以电磁波的形式干扰电气仪表的正常运行。软起动使电动机可以起停自如，减少空转，提高作业率，因而有节能作用。
(1) start process: first select a motor, under the soft starter drag, according to the selected starting mode to gradually increase the output voltage, to reach the power frequency voltage, the bypass contactor is connected. Then, the soft starter is removed from the circuit to start the next motor. (2) stop process: start the soft starter in parallel with the bypass contactor, and then bypass the bypass. Finally, the soft starter gradually reduces the output voltage according to the selected parking mode until stop. 5 application effect through a year of operation, indicating that the device has high reliability, perfect performance, can meet the production requirements. Mainly in the following points: (1) the use of soft starter, the starting current is significantly reduced, reducing the distribution capacity and capacity increase investment. (2) soft starter to achieve smooth start, no impact on the pump and pipe, improve the reliability of power supply and water supply reliability. (3) using soft parking mode to reduce the impact on machinery, prevent water hammer effect, extend the service life of pumps and related equipment. (4) a variety of startup modes and protection functions are integrated into one to prevent accidents. Soft starter can reduce motor hard starting (i.e. direct starting) caused by mains voltage drop, which does not affect the normal operation of network other electrical equipment, can reduce the impact current of the motor, the impact of current motor will cause local temperature rise is too large, reduce motor life, can reduce the mechanical impact caused by hard starting, accelerating momentum the mechanical transmission (gear shaft, etc.) wear, reduce the electromagnetic interference in the normal operation of the impact of current forms of electromagnetic wave interference electrical instrument. Soft start makes the motor stop and move freely, reduce idling and improve operation rate, so it has energy saving effect.
