Siemens Soft Starts
Siemens Soft starters reduce the motor voltage through variable phase control allowing soft starting and soft ramping down of motors. As well as limiting the current soft starts also limit the torque and prevent the mechanical shocks that occur during direct-online and star-delta staring. Siemens 3RW soft starts are suitable for any application in most environments from simple drive applications to sophisticated motor starting where a more heavy duty starting method would be required. Three-phase motors can be started smoothly, simply, and efficiently, and reliable machine concepts implemented using Siemens 3RW starters.
Siemens 3RW40 is a compact starter solution for standard machine applications, with two-phase control enabling three-phase asynchronous motor starting, the two-phase control keeps the current down to minimum values in all three of the motor's phases during the whole starting time. 3RW soft starts are available in power ratings from 5.5 to 250 kW at 400V and control voltages of 24V AC/DC or 110…230V AC/DC.
- 24V AC/DC or 110…230V AC/DC Control Voltage
- Overload Protection
- Two-Phase Control
- Sizes: S00, S0, S2,S3,S6 and S12
Siemens 3RW40 soft starts have a small modular design that has a clearly arranged layout of the control panel and compact screw- or spring-type mounting that saves space in the control cabinet. Units feature box terminals as well as cable lug and busbar connections, plus auxiliary terminals and link module for a motor starter protector. 3RW40 soft starts also fall into the Siemens Sirius size range with soft starts available in sizes S00, S0, S2, S3, S6 and S12. Siemens 3RW40 in soft starter sizes S0 to S12 are also suitable for the starting of explosion-proof motors that require “increased safety” protection EEx e.
3RW40 soft starts do not require the need for additional overloads thanks to the integrated motor overload protection. The rated current and the setting of the overload tripping time (CLASS times) and the reset of the motor overload are all easily adjusted on the front of the soft start. Siemens 3RW40 range can provide up to thirty-eight starts per hour for CLASS 10 starting with a starting time of 3 seconds for a 3RW4036 soft start; this will change dependant upon the size of the soft start selected and both the Class and starting time.