Dc Supply Voltage; General - Siemens SINAMICS S120 Equipment Manual

9.3 24 V DC Supply Voltage
9.3
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.
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.
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 voltage 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
Equipment Manual AC Drive
Manual, (GH6), 03/2006 Edition, 6SL3097-2AL00-0BP0
The Control Units are supplied with power via the PM-IF. 24 V must also be connected in
the following cases:
– Commissioning / diagnostics when the Power Module power supply voltage is
switched-out.
– Using the digital outputs CU310
Cabinet design and EMC for components, Blocksize format
9.3 24 V DC Supply Voltage
9-5