For Operation in the Control Cabinet 3RW Soft Starters © Siemens AG 2009 3RW30 for standard applications Configuration The 3RW solid-state motor controllers are designed for easy starting conditions. In the event of deviating conditions or in- creased switching frequency, it may be necessary to choose a larger device. For accurate dimensioning, use the Win-Soft Starter selection and simulation program. Status graphs U U N If necessary, an overload relay for heavy starting must be se- lected where long starting times are involved. PTC sensors are recommended. U S t R on t In the motor feeder between the SIRIUS 3RW soft starter and the motor, no capacitive elements are permitted (e. g.
no reactive- power compensation equipment). In addition, neither static sys- tems for reactive-power compensation nor dynamic PFC (Power Factor Correction) must be operated in parallel during starting and ramp-down of the soft starter. This is important to prevent faults arising on the compensation equipment and/or the soft starter. ON 13/14 NSB0_01941 All elements of the main circuit (such as fuses, controls and over- load relays) should be dimensioned for direct starting, following the local short-circuit conditions. Fuses, controls and overload relays must be ordered separately. Please observe the maxi- mum switching frequencies specified in the technical specifications.
t R on t Win-Soft Starter selection and simulation program With this software, you can simulate and select all Siemens soft starters, taking into account various parameters such as mains properties, motor and load data, and special application requirements. Note: When induction motors are switched on, voltage drops occur as a rule on starters of all types (direct starters, wye-delta starters, soft starters). The infeed transformer must always be dimen- sioned such that the voltage dip when starting the motor remains within the permissible tolerance.
If the infeed transformer is di- mensioned with only a small margin, it is best for the control volt- age to be supplied from a separate circuit (independently of the main voltage) in order to avoid the potential switching off of the soft starter. The software is a valuable tool, which makes complicated, lengthy manual calculations for determining the required soft starters superfluous. The Win-Soft Starter selection and simulation program can be downloaded from: http://www.siemens.com/softstarter > Software More information can be found on the Internet at: http://www.siemens.
com/softstarter 6 Schematic circuit diagram L1 L2 L3 NSB0_01940 T1 T2 T3 A bypass contact system is already integrated in the 3RW30 soft starter and therefore does not have to be ordered separately. 6/16 Siemens LV 1 T · 2009