The low-voltage soft starter is a motor starting control device used to control the starting process of the motor. It gradually increases the voltage of the motor to achieve the purpose of smooth starting of the motor, and also provides protection against motor overload and short circuit.
When the soft starter is used to start the motor, the output voltage of the thyristor gradually increases, and the motor gradually accelerates until the thyristor is fully turned on. The motor works on the mechanical characteristics of the rated voltage, achieving smooth starting, reducing the starting current, and avoiding starting overcurrent tripping. When the motor reaches the rated number of revolutions, the starting process ends, and the soft starter automatically replaces the thyristor that has completed the task with the bypass contactor to provide the rated voltage for the normal operation of the motor, so as to reduce the heat loss of the thyristor, extend the service life of the soft starter, improve its working efficiency, and avoid harmonic pollution in the power grid. The soft starter also provides a soft stop function. The soft stop process is opposite to the soft start process. The voltage gradually decreases and the number of revolutions gradually drops to zero, avoiding the torque shock caused by free stop.
In principle, cage asynchronous motors can be used in various applications that do not require speed regulation. The application range is AC 380V (660V is also available), and the motor power ranges from a few kilowatts to 800 kilowatts.
The soft starter is particularly suitable for various pump loads or fan loads, and occasions that require soft start and soft stop. In addition, it can be widely used in textile, metallurgy, petrochemical, water treatment, shipbuilding, transportation, medicine, food processing, mining and mechanical equipment.