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

Application planning

3.2 System and load power supply

3.2 System and load power supply
Ty pes of power supplies
The S7-1500 automation system/ET 200MP distributed I/O system distinguishes between
two types of power supply:
● System power supply (PS)
● Load current supply (PM)
System power supply (PS)
The system power supply has a connection to the backplane bus (U connector) and supplies
solely the internally required system voltage. 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.
Load current s upply (PM)
The load current supply feeds the input/output circuits of the modules, as well as the sensors
and actuators of the plant, if installed. The supply of the CPU/interface module with 24 V DC
is optional if you supply the voltage for the backplane bus via a system power supply.
Special c haracteristic of the load current s upply
Load current supplies are mounted on the "S7-1500 mounting rail" and do not have a
connection to the backplane bus.
Total configuration with power s upplies
Figure 3-4 Total configuration with load current supply (PM) and system power supply (PS)
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Automation system
System Manual, 09/2016, A5E03461182-AD