SIRIUS Soft Starters - Siemens

SIRIUS Soft Starters in Practical UseApplication ExamplesSIRIUS 3RW30 – for soft reversingoperation of roller conveyorsSIRIUS 3RW40 – for soft startingof hydraulic pumpsRoller conveyors are, for example, employedin parcel distribution systems fortransporting parcels to and from individualwork stations. For this purpose, thedirection of rotation of the used 11-kWmotor has to be adjustable in order torealize both conveyance directions.Roller conveyors pose highrequirements■ The roller conveyor has to startsmoothly to prevent damage to thetransported goods due to slippingor tilting.■ The machine’s wear and maintenanceintervals should be minimized, whichis why slippage of the belt drive duringstart-up must be prevented.■ The current load upon motor start-upis to be reduced by means of a voltageramp.■ The feeder assembly should be assmall as possible so as to not exceedthe control cabinet’s space capacity.Optimum performance withSIRIUS 3RW30■ The roller conveyor is rapidlyaccelerated to the nominal speedwithout torque surges thanks tooptimum setting of the voltage rampduring start-up.■ The motor’s starting current isreduced.■ Reversing operation of the conveyorbelt is realized through contactorinterconnection with SIRIUS 3RA13reversing contactor combinations.■ Feeder and motor protection arerealized with SIRIUS 3RV circuitbreakers.■ The use of SIRIUS system componentsguarantees maximum wiringreductions and space savings.In addition to many further applicationareas, the SIRIUS 3RW40 is optimally suitedfor the soft start and stop of hydraulicpumps. With a rating of 200 kW, thesesoft starters are for example used in theproduction of sheet parts, to drive therespective presses.Hydraulic pumps require sensitivedrives■ The motor’s starting current has to bereduced to minimize the load of thesuperior mains transformer duringstart-up.■ Normally, integrated motor protectionis called for to reduce wiringexpenditures and space requirementsin the control box.■ The hydraulic pump is to be startedand stopped in a soft manner, tominimize the mechanical load on thedrive and the pump caused by thetorque surge during starting andstopping.20