System And Load Power Supply - Siemens SIMATIC S7-1500 Automation System System Manual

4.2

System and load power supply

In the S7-1500 automation system, you must make a distinction between two different power
supplies:
● System power supply (PS)
● Load current supply (PM)
Figure 4-2 Total configuration with load current supply (PM) and system power supply (PS)
System power supplies
● PS 25W 24V DC: Supply with 24 VDC and 25 W of power
● PS 60W 24/48/60V DC: Supply with 24/48/60 VDC and 60 W of power
● PS 60W 120/230V AC/DC: Supply with 120/230 VAC and 60 W of power
Load power supplies
● PM 70W 120/230 V AC: Supply with 120/230 VAC and 70 W of power
● PM 190W 120/230 V AC: Supply with 120/230 VAC and 190 W of power
S7-1500 Automation System
System Manual, 01/2013, A5E03461182-01
The system power supply has a connection to the backplane bus (U-connector) and
supplies solely the internally required system voltage for the backplane bus. This system
voltage supplies parts of the module electronics and the LEDs. A system power supply
can also supply CPUs or interface modules if these are not connected to a 24 VDC load
current supply.
The load current supply feeds the input/output circuits of the modules, as well as the
sensors and actuators. In addition, you need a load current supply in order to supply the
CPU and the system power supply with 24 VDC. The supply of the CPU with 24 VDC is
optional if you supply the voltage for the backplane bus via a system power supply.
If you are using load current supplies, we recommend the devices from our SIMATIC
series. These devices can be mounted on the mounting rail.
The load current supplies listed below are developed specially for the S7-1500
automation system in the same design. Use of a load current supply is not imperative
since, for example, a SITOP module can be used alternatively.
Application planning
4.2 System and load power supply
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