Siemens SINAMICS S120 Manual page 124

Cabinet design
6.8 Possible functions of the 24 V supply
The following diagrams show the dependencies of motor cable length, motor holding brake
current and cross-section of the motor holding brake cables:
Module input voltage 24 V
Protective circuit against overvoltages
The Motor Modules have an integrated overvoltage protection circuit for the motor holding
brake. External protective circuits are not required.
Note
More information
Further information about conductor protection and the possible functions of the 24 V supply
can be found in the SINAMICS S120 Manual "Booksize Power Units".
122
Module input voltage 26 V
Power Units in Booksize C/D-Type Format
Manual, 12/2018, 6SL3097-5AC20-0BP0