A.2 Principles Of System Installation For Emc - Siemens SIMATIC S7-400 Installation Manual

A.2 Principles of System Installation for EMC
Definition: EMC
EMC (electromagnetic compatibility) describes the capability of electrical apparatus
to operate without faults in a given electromagnetic environment, without being
affected by the environment and without affecting it in an unacceptable manner.
Introduction
Although the S7-400 and its components were developed for operation in an
industrial environment and meet high EMC requirements, you should carry out
EMC planning before installing your control system, taking possible interference
sources into account and incorporating them in your observations.
Possible Effects of Interference
Electromagnetic interference can affect the programmable controller in different
ways:
• Electromagnetic fields which directly affect the system
• Interference picked up via bus signals (PROFIBUS DP, etc.)
• Interference acting via the process wiring
• Interference reaching the system via the power supply and/or protective ground
Figure A-1 shows the possible routes for electromagnetic interference.
Bus signal
Protective ground
Figure A-1
Automation System S7-400 Hardware and Installation
A5E00850741-01
Electromagnetic
fields
Power supply module
The Possible Routes for Electromagnetic Interference
Assembling and Installing Systems
Process wiring
A-5