Siemens SINAMICS S120 Function Manual page 195

When the internal armature short-circuit protection is activated, the same mechanism as with
the internal voltage protection will short-circuit one of the half-bridges in the Motor Module.
After completion of the internal armature short-circuit, it is continued rotor-oriented.
r0046.4
p1230
(1)
Figure 6-4 Internal armature short-circuit
DC brake (induction motors)
The DC brake is activated via the parameter p1231 = 4. It can be triggered via an input
signal p1230 (signal = 1) or a fault response.
Activation of DC brake by BI
If the DC brake is activated by the digital input signal, the first step is that the pulses are
blocked for the demagnetization time p0347 of the motor in order to demagnetize the motor -
the parameter p1234 "Speed at the start of DC braking" is ignored.
Then the DC brake, braking current p1232 is applied as long as the input is initiated in order
to brake the motor or hold it at standstill.
If the DC brake is removed, the drive returns to its selected operating mode.
The following is applicable:
● With servo (controlled with encoder):
● With vector control (controlled with or without encoder):
Drive Functions
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
6.8 Armature short-circuit brake, internal voltage protection, DC brake
1
r0046.20
&
The drive returns to field-oriented control after the demagnetization time has elapsed
(p0347 can also be set to 0). Limitations apply in case of extreme field weakening.
The drive is synchronized with the motor frequency if the "Flying restart" function is
activated, and
F07907
M
~
3
Basic functions
2000 µs
p1231 = 4
195