Electricista

A motor soft starter is a device used with AC electric motors to temporarily reduce the load and torque in the powertrain and electrical current surge of the motor during startup. This reduces themechanical stress on the motor and shaft, as well as the electrodynamic stresses on the attached power cables and electrical distribution network, extending the lifespan of the system.[1]
Motor softstarters can consist of mechanical or electrical devices, or a combination of both. Mechanical soft starters include clutches and several types of couplings using a fluid, magnetic forces, or steel shotto transmit torque, similar to other forms of torque limiter. Electrical soft starters can be any control system that reduces the torque by temporarily reducing the voltage or current input, or adevice that temporarily alters how the motor is connected in the electric circuit.
Electrical soft starters can use solid state devices to control the current flow and therefore the voltage applied tothe motor. They can be connected in series with the line voltage applied to the motor, or can be connected inside the delta (Δ) loop of a delta-connected motor, controlling the voltage applied to eachwinding. Solid state soft starters can control one or more phases of the voltage applied to the induction motor with the best results achieved by three-phase control. Typically, the voltage iscontrolled by reverse-parallel-connected silicon-controlled rectifiers (thyristors), but in some circumstances with three-phase control, the control elements can be a reverse-parallel-connected SCR anddiode.
Another way to limit motor starting current is a series reactor. If an air core is used for the series reactor then a very efficient and reliable soft starter can be designed which is suitable forall type of 3 phase induction motor [ synchronous / asynchronous ] ranging from 25 KW 415 V to 30 MW 11 KV. Using an air core series reactor soft starter is very common practice for applications...