Soft Starters block 3RW44-1

Applications:
1. Conveyor belts
2. Powered roller conveyors
3. Compressors
4. Ventilators,fans
5. Pumps
6. Hydraulic pumps
7. Stirrers
8. Centrifugal machines
9. Milling machines
10. Mills
11. Crushers
12. Disk saws/ribbon saws

Advantages:
1. Conveyor belts and systems
2. Jerk-free starting
3. Jerk-free braking
4. Centrifugal pumps,reciprocating pumps
5. Water hammering is avoided
6. Increased service life of the tubing
7. Stirrers, mixers:
8. Reduced starting current
9. Reduced stress on transmissions and V-belts

This Soft Starters block is easily insert in your schematic diagram and connect as you like way.

The 3RW44 soft starter has two antiparallel thyristors in each of the phases. There is one thyristor for the positive and one thyristor for the negative half wave. Using phase angle control and various control methods, the r.m.s. value of the motor voltage is increased from a definable start voltage or start torque to the motor rated voltage within a selectable starting time. The motor current acts proportional to the voltage applied to the motor. Thus, the starting current is reduced by the factor of the voltage that is applied to the motor. The torque behaves quadratically in relation to the voltage applied to the motor. The starting torque is thus reduced quadratically based on the voltage applied to the motor This means that because the electronic soft starter controls the motor voltage during motor start-up, it simultaneously controls the ingoing starting current and the starting torque generated in the motor. The same principle is also used during the stopping process. The effect is that the torque generated in the motor is slowly reduced, thus enabling soft stopping of the application. During this process, the frequency remains constant and corresponds to the network frequency, contrary to the frequency-controlled starting and stopping of a frequency converter. Upon completion of motor start-up, the thyristors are fully utilized, resulting in the complete network voltage being applied to the motor terminals. Since no motor voltage control is required during operation, the thyristors are bridged by integrated bypass contacts. This reduces the waste heat developing during continuous operation which is caused by power loss of the thyristor. Therefore, the area around the switching devices heats up less. 3RW44 soft starters are an alternative for star-delta starters and frequency converters. Their major benefits are smooth starting and stopping, uninterrupted changeover without current peaks that would stress the power supply, and their compact dimensions. Numerous drives which previously could only be operated with frequency converters can be changed over to soft starter operation using the 3RW44 soft starter, as long as no speed control, no particularly high starting torque or no startup with close to nominal current is required. 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 overdimension 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.