Cascading Of The 24 V Supply; Connections And Interference Suppression - Siemens SINAMICS G120D Original Instructions Manual

4.2.13

Cascading of the 24 V supply

Installation using 24 V bus
The following options are available for the 24 V supply of the inverter:
1. A T distributor with integrated power supply unit supplies the 24 V.
2. An external power supply unit supplies the 24 V.
The inverter can conduct a maximum current of 8 A through its 24 V connector.
Figure 4-16
4.2.14

Connections and interference suppression

All connections should be made so that they are permanent. Screwed connections on
painted or anodized metal components must be made either by means of special contact
washers, which penetrate the isolating surface and establish a metallically conductive
contact, or by removing the isolating surface on the contact points.
Contactor coils, relays, solenoid valves, and motor holding brakes must have interference
suppressors to reduce high-frequency radiation when the contacts are opened (RC elements
or varistors for AC currentoperated coils, and freewheeling diodes for DC current-operated
coils). The interference suppressors must be connected directly on each coil.
Converter with control units CU250D-2
Operating Instructions, 04/2014, FW V4.7, A5E34261542B AA
Advantage: Low installation costs.
Advantage: You can switch off the 400 V without interrupting the 24 V supply and thus
the fieldbus communication of the inverter.
24 V bus from T distributor or with separate power supply
Installation
4.2 Electrical Installation
51