A Softstart or soft starter is an electrical device used for temporary reduction of the power load and torque when starting up an AC motor, in order to even out inrush current surges during the start-up. This cuts down on mechanical stress to the motor and drive shaft, and on electrodynamic stress to power cables and the electrical distribution network, ultimately extending the motor's lifespan.
Softstarts work by continuously controlling the voltage supply of three-phase motors during the initial start-up phase so that the motor adjusts to the load behaviour. Smooth acceleration of mechanical operating equipment improves its performance and work flows, and increases the stability of the energy supply. Softstarts can be configured to many applications: smooth starting of conveyor belt systems avoids unnecessary stress on mechanical drive components, soft starting of pump applications evens out pressure surges, and slow start-up of belt drives avoids slippage.
At Rowse Automation we can supply a range of basic performance Softstarts designed for three-phase asynchronous motors, together with appropriate programming software. Units are small and compact in design to save space, with a clearly arranged layout of the control panel and integrated diagnostic functions. Overload and device protection are built in, and there is an integrated bypass contact system.
These units are available in adjustable trip classes and offer full motor protection, as well as optional thermistor protection. Easy to install and operate, Softstarts will also reduce operational power losses, and avoid the peaking in current and torque which can occur with other starter types, such as wye-delta.