Siemens SIRIUS 3RW55 Manual page 105

Parameters
NOTICE
Property damage due to DC braking pulses
DC braking pulses cause a higher current load and motor-specific noises and vibrations.
This can lead to premature failure of motor bearings. It may be necessary to overdimension
the soft starter.
Parameters
Stopping time
DC braking torque
Dynamic braking
torque
SIRIUS 3RW55 soft starter
Manual, 08/2018, A5E35630887002A/RS-AB/002
Description
The stopping time specifies the period during which the DC braking torque is to
be generated on the motor. The chosen braking time should be long enough to
bring the load to a standstill. To achieve an adequate braking effect down to
standstill, the centrifugal mass (J) of the load should not exceed that of the
motor. The length of the stopping time should be chosen such that the motor
comes to a standstill. Standstill detection does not take place in the soft starter
and, if required, must be realized by means of external measures.
The actual stopping time may vary with this braking process.
The motor's braking force can be set with the amount of the DC braking torque.
The dynamic braking torque must be increased if the motor is to accelerate
again during DC braking.
Factory setting: 50%
•
Setting range: 20 ... 100%
•
Increment: 5%
•
The dynamic braking torque determines the braking effect at the start of the
braking process to reduce the speed of the motor. Following this, the braking
operation is continued automatically with the "DC braking" function.
Factory setting: 50%
•
Setting range: 20 ... 100%
•
Increment: 5%
•
Functions
7.3 Run-down
105