Question:

When using any of the PCS or PF Softstart products, which starting mode or profile should I select? What is the difference between Current Limit and Soft Start starting modes? Which starting mode can reduce High Inrush Currents, Excessive Starting Torque, Peak Demand Utility Charges, Damage, Loss or Spillage of Product?

Answer:

For detailed and specific information to set parameters, use the Sprecher + Schuh Literature Library to download the Application Techniques guide, Quick Start guides and User Manuals for the specific Soft Start product being used in your application.

To Reduce High Inrush Currents

This can be accomplished by using the Current Limit Start mode. This functionality is the most basic feature of all Soft Start products. Current Limit mode allows the user the ability to set a specific limit of starting current (Current Limit Starting Level parameter) for a set period of time. The result is the motor comes up to speed slower than both a Soft Start and Full Voltage Starting mode, but requires less peak current and avoids power disturbances.

To Reduce Excessive Starting Torque

This can be accomplished by using the Soft Start mode. This is another basic feature of the Soft Start products. The Soft Start method allows the user the ability to select an Initial Torque value and then ramp up the torque from that point over a set period of time. The result of this technique is limited torque and smooth acceleration helping to avoid mechanical wear and tear.  Both the current and voltage are allowed to rise gradually in Soft Start mode.

To Reduce Peak Demand Utility Charges

Through the use of Current Limit Starting, peak demand charges can be limited or in some cases eliminated since the peak current draw of the motor during starting is user adjustable. The combination of Current Limit starting and system or facility wide motor starting coordination can yield significant improvements in power usage.

To Reduce Damage, Loss Or Spillage Of Product

This can be achieved through the use of Soft Start mode.

For additional information please contact your nearest authorized distributor, sales representative, or call our customer service or technical support lines.