Siemens SIRIUS 3RW44 - Configuration Instructions; 2.1 Configuration; 2.2 Normal or Heavy Starting; 2.3 On-time and Switching Frequency

Configuration Instructions
SIRIUS 3RW44 manual
GWA 4NEB 535 2195-02 DS 02
2-3
2.2 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 9.3.2 "Technical
Data Power Electronics". 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 (refer to Chapter 9.3.8 "Accessories" software).
Selection criteria
Note
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).
2.2.1 Application Examples for Normal Starting (CLASS 10)
2.2.2 Application Examples for Heavy Starting (CLASS 20)
Normal starting Class 10 (up to 20 s with 350 % I
n motor
),
The soft starter rating can be selected to be as high as the rating of the motor used
Application Conveyor belt Roller conveyor Compressor Small ventilator Pump Hydraulic pump
Starting parameters
• Voltage ramp and current
limiting
- Starting voltage % 70 60 50 30 30 30
- Starting time s
10 10 10 10 10 10
- Current limit value
Deactivated Deactivated 4xI
M
4xI
M
Deactivated Deactivated
• Torque ramp
- Starting torque 60 50 40 20 10 10
-End torque
150 150 150 150 150 150
- Starting time
10 10 10 10 10 10
• Breakaway pulse
Deactivated (0 ms) Deactivated (0 ms) Deactivated (0 ms) Deactivated (0 ms) Deactivated (0 ms) Deactivated (0 ms)
Ramp-down mode
Smooth
ramp-down
Smooth
ramp-down
Free ramp-down Free ramp-down Pump ramp-down Free ramp-down
Heavy starting Class 20 (up to 40 s with 350 % I
n motor
),
The soft starter has to be selected one rating class higher than the motor used
Application Stirrer Centrifuge Milling machine
Starting parameters
• Voltage ramp and current
limiting
- Starting voltage % 30 30 30
- Starting time s
30 30 30
- Current limit value
4xI
M
4xI
M
4xI
M
• Torque ramp
- Starting torque 30 30 30
-End torque
150 150 150
- Starting time
30 30 30
• Breakaway pulse
Deactivated (0 ms) Deactivated (0 ms) Deactivated (0 ms)
Ramp-down mode
Free ramp-down Free ramp-down Free ramp-down or DC braking