Dc Supply Voltage; General - Siemens SINAMICS S120 Equipment Manual

8.3 24 V DC supply voltage
8.3
8.3.1

General

The 24 V DC voltage is required for the power supply of:
1. The electronics of the SINAMICS components via the integrated 24 V busbar
2. The electronics of the Control Units, Option Boards, Sensor Modules, and Terminal
3. The load voltage of the digital outputs
4. The motor holding brakes
Other loads can be connected to these power supply units if they are separately protected
from overcurrent.
Notice
If other consumers are connected to the power supply, connected inductance devices
(contactors, relays) must be fitted with suitable overvoltage protection circuits.
Notice
A regulated DC power supply is required to operate motors with a built-in holding brake. The
voltage is supplied via the internal 24 V busbars. The voltage tolerances of the motor holding
brakes and the voltage drops of the connection cables must be taken into account.
The DC power supply should be set to 26 V. The Control Supply Module supplies 26 V. This
ensures that the supply voltage for the brake remains within the permissible range when the
following conditions are fulfilled:
• Using Siemens three-phase motors
• Using Siemens MOTION-CONNECT power cables
• Motor cable lengths: max. 100 m
Equipment Manual for Booksize Power Units
Equipment Manual, (GH2), 03/2006 Edition, 6SL3097-2AC00-0BP3
Modules, as well as the process voltage of their digital inputs
Cabinet Configuration and EMC Booksize
8.3 24 V DC supply voltage
8-5