Sep 07, 2020
About the selection of soft starter-Part 1
Type selection: The common soft starters currently on the market include bypass type, no bypass type, and energy-saving type. Choose different types of soft starters according to the nature of the load.
Bypass type: When the motor reaches the rated number of revolutions, the bypass contactor replaces the soft starter that has completed the task to reduce the heat loss of the thyristor and improve its work efficiency. One soft starter can also be used to start multiple motors.
No bypass type: The thyristor is in full conduction, the motor works in full voltage mode, ignoring voltage harmonic components, and is often used for motors that repeatedly work when short-circuited.
Energy-saving type: When the motor load is light, the soft starter automatically reduces the voltage applied to the motor stator, reduces the motor current excitation component, and improves the motor power factor.
Selection of specifications: Select the starter according to the nominal power of the motor and the nature of the current load. Generally, the capacity of the soft starter is slightly larger than the working current of the motor. It should also consider whether the protection function is complete, such as: phase loss protection, short circuit protection, overload protection, reverse sequence protection , Overvoltage protection, undervoltage protection, etc.