Dc Supply Voltage; General - Siemens SINAMICS S120 Manual

Cabinet Design and EMC for Components, Blocksize Format
9.3 24 V DC supply voltage
9.3 24 V DC supply voltage
9.3.1

General

The 24 V DC voltage is required for the power supply of:
1. The load voltage of the Control Unit digital outputs.
The Control Units are supplied with power via the PM-IF. 24 V must also be connected in
the following cases:
2. The electronics of the Sensor Module
3. The Safe Brake Relay (motor holding brake)
Other loads can be connected to these power supply units if they are separately protected
from overcurrent.
Note
The user should provide the electronics power supply as described in Chapter "System data"
in this documentation.
When connecting to a "DC power supply" in the sense of EN 60204-1:1997, Chapter 4.3.3,
functional faults can occur due to the voltage interruptions that are permitted there.
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 power is supplied via the 24 V connection (Safe Brake Relay). 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. This ensures that the power supply 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
294
– Commissioning / diagnostics when the Power Module power supply is switched-out.
– Using the digital outputs CU310
Manual, (GH6), 07/2007 Edition, 6SL3097-2AL00-0BP2
AC Drive