Power Balance Calculation - Siemens SIMATIC S7-1500 System Manual

Application planning

3.4 Power balance calculation

3.4 Power balance calculation
Principle of power balance calculation
In order to ensure the supply of the modules from the backplane bus, the infed power is
compared with the required power. The power balance calculation checks whether the power
provided by the system power supplies including CPU/interface module is greater than or
equal to the power used by the consumers (modules).
In order to operate the configuration with its used modules, the power balance must be
positive for each power segment in use.
This means that the power fed into the power segment is greater than the power consumed
by the modules.
Take care even during planning, that the power fed into the backplane bus is always greater
than or equivalent to the power drawn.
The power fed into the backplane bus by the CPU/interface module and system power
supply is listed in the technical specifications of the CPU/interface module in the
corresponding manuals.
The power consumed from the backplane bus by an I/O module or the CPU/interface module
can be found in the technical specifications in the corresponding manuals.
The power balance calculation is performed:
● During planning with STEP 7
● During operation by the CPU
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Automation system
System Manual, 12/2014, A5E03461182-AC