Use Of System Power Supplies - Siemens SIMATIC S7-1500 System Manual

Application planning
3.2 System and load power supply
3.2.1

Use of system power supplies

Introduction
If the power fed from the CPU/interface module into the backplane bus is not sufficient to
supply all connected modules with power, system power supplies (PS) are required.
Whether or not you need a system power supply depends on the power consumption of the
modules used. The power supplied by the CPU/interface module and the system power
supplies must be greater than the power required by the I/O modules.
During configuration, STEP 7 compares the supplied power and the power required by the
modules. If the required power is too high, you receive a corresponding message from
STEP 7.
Slots for system power supplies
The following slots may be used for system power supplies:
● A system power supply in slot 0 to the left of the CPU/interface module
● Up to 2 system power supplies in the slots to the right of the CPU/interface module
(power segments) A power segment consists of a power supply module and the modules
supplied by it.
Power segment
If you are using system power supplies to the right of the CPU/interface module, divide the
configuration into power segments.
Configuration v ariant with power segments
Figure 3-5
Not e
If you use the TIA Portal for configuring, it automatically checks the configuration for
consistency and informs you as of which module you must open up a new power segment.
40
Configuration variants with 3 power segments
Automation system
System Manual, 09/2016, A5E03461182-AD