Siemens SIRIUS 3RW55 Equipment Manual page 161

The stopping mode "Reversing DC braking" with a reversing contactor assembly and the
"reversing operation" function use the same line contactors. You will find further information on
the method of operation in chapter Reversing duty (Page 322).
Application
• Applications that have to be braked quickly
Validity
This stopping mode is not available for the 3RW55 Failsafe soft starter.
Requirements
• 3RW55 soft starter from firmware version V2.0
• External reversing contactor assembly comprising 2 mechanically interlocked contactors
• 2 digital outputs
• 3RW55 soft starter in standard (inline) circuit
• Ex operation not active
Setting via 3RW5 HMI High Feature
• Menu: "Parameters > Soft Starter > Parameter set 1 / 2 / 3 > Stopping mode settings >
Stopping mode > Reversing DC braking"
• Menu (Parameters): "Parameters > Soft Starter > Parameter set 1 / 2 / 3 > Stopping mode
settings"
• Access protection to the 3RW5 HMI High Feature is not active or has been reset.
Parameters
Parameters
Stopping time
Dynamic braking torque
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006
Description
The length of the stopping time determines the duration of braking. The setting "0 s" causes
termination without DC braking.
• Factory setting: 10 s
• Setting range: 0 ... 360 s
• In steps of: 0.1 s
The dynamic braking torque determines the magnitude of the braking effect in the first braking
phase to reduce the speed of the motor via reversing operation. In this way, the duration of the
reversing operation in the first braking phase can be changed to avoid rotation in the opposite
direction after braking. If you want to prolong the first braking phase, increase the dynamic
braking torque, e.g. to 70%. If the motor rotates in the opposite direction after braking, reduce
the dynamic braking torque, e.g. to 30%. The factory setting 50% corresponds to a reduction
of approx. 80% of the energy in the first braking phase.
• Factory setting: 50%
• Setting range: 20 ... 100%
• In steps of: 5%
Functions
8.2 Run-down
161