Motor Technology: Increasing Energy Efficiency with a Soft Starter

March 31, 2011 - PRLog -- A motor soft starter is a device used with AC electric motors to temporarily reduce the load and torque in the powertrain of the motor during start up.

In the world of automation, AC induction motors have retained much of their original design features for the last one hundred years. However, there are now many more options available in the method of starting and stopping them.

The traditional method of starting a motor is direct on line or DOL, where the power is simple applied to the motor via a contact.

This however, can cause several issues:


•  High starting current (up to 6 times the full load)
•  Excessive starting torque up to 2.5 times the normal running value which can cause a jerking motion on the conveyor, pump etc. This also stresses chains, belts, pulleys and gearboxes connected to the motor.


A possible solution to these problems is the implementation of a Soft Start:

The soft start is designed to apply an adjustable voltage to the motor and increase the voltage gradually over a user-selectable acceleration period. The acceleration time being dependent on the application and desired characteristics.

The added advantage of this method of reduced voltage control is that the motor can also be stopped gradually by slowly reducing the output voltage to the ‘Soft Stop’ feature.

The soft stop feature, offers a smooth stop in many process industries such as pumps, where fast stops can result in ‘water hammer’ and mechanical damage or conveyors where bottles may fall over.

Recently Soft Start pricing has reduced to a level where they can even pay for themselves immediately by being able downsize the current rating in the installation now a large peak does not occur on start up.

So if you want to benefit from:

•  Reduced starting current
•  Reduced starting torque
•  Less mechanical stress
•  Improved control of acceleration and deceleration

Overall, Soft Starters provide a useful application for managing the outputs of motors to ensure components do not overload themselves and that motors can operate in a more controlled manner.

http://www.more-control.com/more.html

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More Control is a dedicated supplier of automation parts and bespoke automation solutions in the UK. Combining technical expertise with quality customer service, More Control offers a unique approach to the buying and selling of automation equipment.