Braking Resistors (Armature Short-Circuit Braking); Function Description - Siemens SIMOTICS T-1FW3 Configuration Manual

Finally, the other motor features must be defined This is realized by appropriately configuring
the motor options.
5.3

Braking resistors (armature short-circuit braking)

5.3.1

Function description

Function description
For transistor PWM converters, when the DC link voltage values are exceeded or if the
electronics fails, then electrical braking is no longer possible. If the drive which is coasting
down, can represent a potential hazard, then the motor can be braked by short-circuiting the
armature. Armature short-circuit braking should be initiated at the latest by the limit switch in
the traversing range of the feed axis.
The friction of the mechanical system and the switching times of the contactors must be
taken into account when determining the distance that the feed axis takes to come to a
complete stop. In order to avoid mechanical damage, mechanical stops should be located at
the end of the absolute traversing range.
For servomotors with integrated holding brake, the holding brake can be simultaneously
applied to create an additional braking torque – however, with some delay.
NOTICE
Damage to the converter
If an armature short-circuit contactor is energized or de-energized before the converter
pulses are canceled, then the contactor contacts can burn and the converter can be
destroyed.
• You must always ensure that the converter pulses are first canceled and this actually
Operational braking not functioning
If the brake is not connected to the setpoint input intended for the purpose, then the brake
is not controlled and the motor will not be braked.
• For operational braking, connect the brake via the setpoint input. Observe the
For electrical braking using armature short-circuit of the stator, consult the documentation of
the drive system being used.
1FW3 complete torque motors
Configuration Manual, 08/2020, A5E46027705B AA
implemented.
WARNING
information in the converter configuration manual.
5.3 Braking resistors (armature short-circuit braking)
Configuration
103