Normal or Heavy Starting

To properly dimension a soft starter, it is important to know and take into account the starting time (normal or heavy starting) of the application. Long starting times mean a higher thermal load for the thyristors of the soft starter. The 3RW44 soft starters are designed for continuous operation under normal starting conditions
(CLASS 10), an ambient temperature of 40 degrees Celsius and a fixed switching frequency. You can also find these values in Chapter 10.3.2 "Technical Data Power Unit". If deviations from these data occur, it may be necessary to over dimension the soft starter. Using the Win Soft Starter selection and simulation program from SIEMENS, you can enter your application data and requirements, and it will determine the optimum soft starter dimensions for your application

Selection criteria

The adequate size of the SIRIUS 3RW44 soft starters must be selected on the basis of the motor rated current (Rated current soft starter ≥motor rated current).