Soft Starting With Voltage Ramp; Soft Starting With Voltage Ramp (Page 134) - Siemens SIRIUS 3RW55 Equipment Manual

Functions
8.1 Start-up
Mode
Preset starting time
(Identical to the parameter of
the Starting time monitoring
(Page 181))
Current limiting value - maxi‐
mum
Result
Once the parameters have been stored, you can view the automatically determined values in the
parameter settings of the respective parameter set. If you deactivate automatic
parameterization, the stored values are no longer modified. The parameters learned in the
3RW55 or 3RW55 Failsafe soft starter are only overwritten if the device is parameterized again.
Deactivating automatic parameterization
To deactivate automatic parameterization, set the parameter "Mode" to "OFF".
8.1.3

Soft starting with voltage ramp

Operating principle
A voltage ramp is used to implement soft starting. The 3RW55 or 3RW55 Failsafe soft starter
increases the motor voltage from a parameterizable starting voltage to the line voltage within a
definable ramp-up time.
Application
• E.g. pumps or small fans
134
Select the mode depending on the selected application, depending on whether current limit‐
ing is recommended or not. You can change the mode manually at any time.
Off (factory setting)
The function is deactivated.
On - with preset starting time
The motor should have reached the rated operating speed after a specified starting time.
On - with preset starting time and current limiting
The motor should reach the rated operating speed after a specified starting time if the current
value is limited.
The time after which the motor should have reached its rated operating speed.
With the setting "0 s", there is no automatic parameterization.
For the PRESET starting time the ramp-up time is adopted as the start value. Change the preset
values as required.
• Factory setting: 4 s
• Setting range: 0 ... 360 s
• In steps of: 0.1 s
This parameter only takes effect in connection with the parameter "Mode" (On - with preset
starting time and current limiting).
Depending on the selected application, the corresponding preset values are used for this
parameter. Change the preset values as required.
• Factory setting: 400%
• Setting range: 125 ... 800%
• In steps of: 1%
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006