Armature Short-Circuit Braking - Siemens SIMODRIVE 611 Configuration Manual

Motor Components

5.3 Armature short-circuit braking

5.3 Armature short-circuit braking
5.3
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.
Caution
The drive converter pulses must first be canceled and this actually implemented before an
armature short-circuit contactor is closed or opened. This prevents the contactor contacts
from burning and eroding and destroying the drive converter.
Warning
The drive must always be operationally braked using the setpoint input. For additional
information, refer to the Drive Converter Configuration Manual.
Brake resistors
The optimum braking torque of the servomotor in regenerative operation can be obtained
using armature short-circuit with a matching external resistor circuit.
The resistors which must be externally mounted are described in the appropriate Motor
Configuration Manual.
Ordering address:
Tel.:
5-4
Fritzlen GmbH & Co.KG
Gottlieb-Daimler-Str. 61
71711 Murr
Germany
+49 (0) 7144 / 2724 - 25
Configuration Manual, (PJAL), 11.2005 Edition, 6SN1 197-0AD07-0BP4
General Section for Synchronous Motors