Siemens SIMATIC S7-1500 Automation System User Manual

Application planning
4.3 Power balance calculation
S7-1500 Automation System
System Manual, 01/2013, A5E03461182-01
35
4.3 Power balance calculation
Introduction
In order to ensure the supply of the modules from the backplane bus, the infed power is
compared with the required power. In a power balance calculation the system checks
whether the power provided by the system power supplies including CPU 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.
Negative power balance: The infed power is less than the power consumed by the modules
in the power segment.
Positive power balance: The infed power is greater than the power consumed by the
modules in the power segment.
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 from the CPU and system power supply is listed in the
technical data of the CPU in the corresponding Manual
(http://support.automation.siemens.
com
/WW/view/en/57251228).
The power drawn from the backplane bus by an I/O module or the CPU is listed in the
technical data of the CPU in the corresponding Manual
(http://support.automation.siemens.com
/WW/view/en/57251228).
The power balance calculation is performed:
● During planning with STEP 7
● During operation by the CPU

Siemens SIMATIC S7-1500 Automation System Specifications

General

Series	SIMATIC S7-1500
Programming	TIA Portal (Totally Integrated Automation Portal)
Protection Class	IP20
CPU	Various models available (e.g., CPU 1511-1 PN, CPU 1518-4 PN/DP)
Controller Type	Modular Controller
Programming Languages	LAD, FBD, STL, SCL, GRAPH
Communication Interfaces	PROFINET, PROFIBUS, Ethernet, OPC UA
Digital Inputs	Varies by model and expansion modules
Digital Outputs	Varies by model and expansion modules
Analog Inputs	Varies by model and expansion modules
Analog Outputs	Varies by model and expansion modules
Backplane Bus	High-speed backplane bus for fast communication between modules
Redundancy	Supported with specific models and configurations
Safety	Integrated safety functions available
Scalability	Highly scalable with modular expansion
Operating Temperature	0°C to 60°C