Possible Functions Of The 24 V Supply - Siemens SINAMICS S120 Manual

Cabinet design

6.8 Possible functions of the 24 V supply

6.8 Possible functions of the 24 V supply
The 24 V DC voltage is required for:
● To supply the electronics of the SINAMICS components via the integrated 24 V busbar
● To supply the electronics of the Control Units, Active Interface Modules, Option Boards,
Sensor Modules, and Terminal Modules, as well as the process voltage of their digital
inputs
● To supply the load voltage of the digital outputs
● To supply the motor holding brakes
Other loads can be connected to these power supply units if they are separately protected
from overcurrent.
The 24 V busbars have a current-carrying capacity of 20 A. They must be protected against
overcurrent.
Note
The electronics power supply should be implemented by the user, as described in Chapter
"System data" (Page 35).
When connecting a DC power supply as specified in EN 60204-1:1997, Sect. 4.3.3,
malfunctions may occur due to the voltage interruptions permitted for them.
Note
Grounding the 24 V electronics power supply
In SINAMICS S120 components, the electronics ground is permanently connected to the
protective conductor potential. The connection cannot be disconnected.
Electric shock due to unsuitable insulation of brake cables
When routing brake cables, whose insulation properties are not suitable fo safe electrical
separation, then the insulation can fail resulting in electric shock.
• Connect the holding brake with the specified MOTION-CONNECT cable.
• Only use third-party cables that have brake conductors with insulation properties that
120
WARNING
comply with safe electrical separation or separately route the brake conductors to
absolutely ensure safe electrical separation.
Power Units in Booksize C/D-Type Format
Manual, 12/2018, 6SL3097-5AC20-0BP0