Siemens SIRIUS 3RW44 System Manual page 106

Device Functions
Stopping time
Stopping mode: DC braking
DC braking torque
6-14
The stopping time determines how long braking torque is applied to the motor.
The braking time should be long enough to bring the load to a complete
standstill.
To achieve a sufficient brake effect until standstill, the centrifugal mass (J) of the
load should not exceed that of the motor. The stopping time should be selected
such that the motor comes to a standstill. The soft starter has no standstill
recognition; if required, this must be accomplished using external measures.
Note
The real stopping time can vary during braking processes when the combined
braking function is applied.
Motor
torque
M
M
Nominal operation
DC braking torque
Dynamic
braking torque
Motor
braking torque
Figure 6-8:Combined braking
If the DC braking function is selected, the stopping time and DC braking torque
parameters can be configured on the starter. With this braking type, one output
of the soft starter must be switched over to DC braking to control an external
brake contactor. Please refer to Chapter 9 for wiring suggestions.
The optimum parameters must be adjusted on the machine under appropriate
load conditions.
The DC braking torque determines the brake force of the motor.
Stop command
at soft starter
Stopping time
Time (t)
s
SIRIUS 3RW44 System Manual
GWA 4NEB 535 2195-02 DS 04