Three-phase asynchronous motors are widely used in industry because they have a simple structure, are easy to fabricate, work with reliability, but they have the disadvantage of large starting current, which causes a voltage drop in the grid. Therefore, to solve this problem, manufacturers have come up with solutions for soft start and inverter starting to control so that they can limit the starting current while adjusting the open torque. The engine is properly engineered, so the parts of the engine are subject to less mechanical compression, increasing the working life of the engine safely. In addition to avoiding peak currents while starting the engine, it also makes the supply voltage more stable without adversely affecting other equipment in the grid.

The application of the soft starter cabinet is of great significance and very important in industry because it saves great energy, increases the working life of the operating engine and does not affect other equipment in the grid when the engine is operating. This application is very valuable for controlling the voltage applied to the motor which will reduce the inrush current to 1.5 to 3 times the rated current depending on the load mode because when the motor is closed directly to the current grid start-up of the induction motor will be very large 5 to 7 times of the rated current.