Siemens SIMATIC S7-1500 System Manual page 308

Infeed via the R/H-CPU
Supply the R/H-CPU with the permissible 24 V DC supply voltage.
Follow these steps to set up the infeed via the R/H-CPU:
1. In STEP 7, open the "Properties" tab for the R/H-CPU. Select "System power supply" in the
navigation.
2. Select the option "Connection to supply voltage L+".
Figure 9-12
Infeed via R/H-CPU and system power supply
Supply the system power supply with the permissible supply voltage and the R/H-CPU with
24 V DC.
Both the system power supply and the R/H-CPU supply current to the backplane bus. The
supplied power is summed.
Power addition: Infeed power of the system power supply + infeed power of the R/H-CPU
Follow these steps to set up the infeed via the R/H-CPU and system power supply:
1. In STEP 7, open the "Properties" tab for the R/H-CPU. Select "System power supply" in the
navigation.
2. Select the option "Connection to supply voltage L+".
Figure 9-13
Infeed via system power supply only
You can also feed the required power into the backplane bus using only a system power
supply. In this case, the R/H-CPU is supplied from the backplane bus rather than with 24 V DC.
In general, you can use a system power supply with AC or DC infeed for the configuration.
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
Supply voltage via R/H-CPU only
Supply voltage system via the R/H-CPU and system power supply
9.7 Configuring the system power supply
Configuration
307