Siemens SIRIUS 3RW40, Manual

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Application planning
6.1 Application examples
SIRIUS 3RW30 / 3RW40
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Manual, 01/2010, 535 1995-02 DS01
6.1.2 Hydraulic pump application
Using the 3RW40 with hydraulic pumps
The SIRIUS 3RW40 is optimally suited for soft starting and stopping of hydraulic pumps. With
a rating of 200 kW / 250 hp, this soft starter is used, for example, in the production of sheet
parts to drive the presses.
The drives for hydraulic pumps must meet the following requirements:
• The motor's starting current has to be reduced to minimize the load on the higher-level
mains transformer during startup.
• Integrated motor protection is called for to reduce wiring expenditure and space
requirements in the control box.
• The hydraulic pump must be started and stopped in a soft manner to minimize the
mechanical load on the drive and the pump caused by torque surges during starting and
stopping.
The SIRIUS 3RW40 soft starter offers the following advantages:
• The settable current limiting of the SIRIUS 3RW40 limits the load on the mains transformer
during the motor startup.
• Motor protection is ensured by the motor overload relay with settable tripping times
integrated in the soft starter.
• The adjustable voltage ramp ensures that the hydraulic pump is started and stopped
without torque surges.