Internal Voltage Protection - Siemens SINAMICS S120 Function Manual

Basic functions
8.13 DC braking
Setting the function
If p1231 is set to 14, DC braking as a response is activated as soon as the actual speed falls
below p1234.
Activating the function
Before activation, the actual speed must be > p1234. The DC braking can then be activated
when both of the following conditions are met:
● The actual speed has fallen below p1234.
● The signal source of p1230 is set to "1".
If the function is activated as a response to a speed threshold, then the following responses are
executed:
1. The pulses are first disabled. As a consequence, the motor is demagnetized. DC braking is
then initiated for the duration p1233. The motor is braked with the braking current p1232.
2. If the signal source of p1230 is set to "0", the braking command is canceled and the drive
goes back into the previous operating mode.
3. DC braking for OFF1 or OFF3 is only executed if the signal source of p1230 is set to "1".
4. DC braking as emergency braking of a fault response remains active.
8.13.5

Internal voltage protection

Function description
With the integrated voltage protection is active, after the pulses have been canceled, all the
motor terminals are at half of the DC link potential (without integrated voltage protection the
motor terminals have a no voltage condition)!
● Only short-circuit proof motors must be used (p0320 < p0323).
● The Motor Module must be able to withstand the 1.8-fold short-circuit current (r0320) of the
motor (r0209).
● The internal voltage protection function cannot be interrupted due to a fault response. If an
overcurrent occurs while internal voltage protection is active, the Motor Module and/or the
motor might sustain irreparable damage.
● If the Motor Module does not support the autonomous, integrated voltage protection
mechanism (r0192.10 = 0), an external 24 V supply (UPS) must be provided for the
components to ensure reliable operation in the event of mains power failure.
● If the Motor Module supports the autonomous, integrated voltage protection mechanism
(r0192.10 = 1), the 24 V supply for the components must be implemented via a Control
Supply Module to ensure reliable operation in the event of mains power failure.
● When the internal voltage protection function is active, the motor must not be powered by
an external source for an extended period of time (e.g. by loads that move the motor or
another coupled motor).
The internal voltage protection is set with p1231 = 3.
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Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions