S611 Soft Starter MN03902011E—May 2012 www.eaton.com 19Current Limit StartThis mode is typically used when it is necessary to limit the maximum current during start-updue to line power limitations or other considerations. During a current limit start the S611applies a constant voltage to the motor, resulting in limited current flowing through themotor’s windings. The level of current is set by the Initial Torque parameter. (See figurebelow.)Note: Current limit starts are not recommended on variable torque load applications like fansand pumps. Attempting starts with the current limit set to a value of 20% initial torqueor lower are not recommended.Current LimitSoft Stop/Pump Stop—This feature is used for applications that require a controlledextended stop. It is designed for high frictional loads that tend to stop suddenly or to preventwater hammer (pumps) when voltage to the motor is removed. During soft stop, the voltageis gradually reduced to zero in the time set by the Soft Stop Time parameter. (See figurebelow.)Note: The soft stop mode is not an electronic brake function and will not stop a motor anyfaster than it would normally take to coast to a stop under load.Soft StopInitialTorqueKickStartTorqKick Start Time100%Bypass BypassSoft Start TimeStart RunCurrentTime (Seconds) Time (Seconds)100%Start RunSpeedSoftStop Time100%Run Soft StopSpeedTime (Seconds)Coast to Stop(Speed)Soft Stop Ramp(Voltage)www.comoso.com
