Siemens SINAMICS S120 Equipment Manual page 136

Cabinet Configuration and EMC Booksize
6.3 24 V DC supply voltage
Table 6-8 MCBs by conductor cross-section and temperature
Conductor cross-section
1.5 mm
2
2.5 mm
2
4 mm
2
6 mm
2
24 V busbar
The trip characteristic of the MCBs must be selected to match the loads to be protected and
the max. current provided by the power supply unit in the event of a short-circuit.
Example for calculating 24 V DC current requirements
Table 6-9 Example of 24 V DC current requirements
Component
CU320
8 digital outputs
Active line module 36 kW
Motor module 18 A
Motor module 30 A
SMC20
Brake
Total:
6-12
Max. value up to 40 °C
10 A
20 A
25 A
32 A
20 A
Number
1
8
1
2
3
10
5
Max. value up to 55 °C
10 A
10 A
16 A
25 A
20 A
Current consumption
[A]
0.4
0.1
1.7
0.7
0.8
0.25
1.1
Equipment Manual, (GH2), 04.2004 Edition, 6SL3097-2AC00-0BP0
Total current consumption
[A]
0.4
0.8
1.7
1.4
2.4
2.5
5.5
14.7
Booksize Power Sections