Siemens Simatic S7-300 CPU 31xC Series User Manual

Table of contents
S7-300, CPU 31xC and CPU 31x: Installation
x Operating Instructions, Edition 08/2004, A5E00105492-05
A Appendix.................................................................................................................................................A-1
A.1 General Rules and Regulations for S7-300 Operation ..............................................................A-1
A.2 Protection against electromagnetic interference........................................................................A-3
A.2.1 Basic Points for EMC-compliant system installations ................................................................A-3
A.2.2 Five basic rules for securing EMC .............................................................................................A-5
A.2.2.1 1. Basic rule for ensuring EMC ..................................................................................................A-5
A.2.2.2 2. Basic rule for ensuring EMC ..................................................................................................A-5
A.2.2.3 3. Basic rule for ensuring EMC ..................................................................................................A-6
A.2.2.4 4. Basic rule for ensuring EMC ..................................................................................................A-6
A.2.2.5 5. Basic rule for ensuring EMC ..................................................................................................A-7
A.2.3 EMC-compliant installation of PLCs...........................................................................................A-7
A.2.4 Examples of an EMC-compliant installation: Cabinet installation..............................................A-9
A.2.5 Examples of an EMC-compliant installation: Wall mounting....................................................A-10
A.2.6 Cable shielding.........................................................................................................................A-12
A.2.7 Equipotential bonding...............................................................................................................A-14
A.2.8 Cable routing inside buildings ..................................................................................................A-16
A.2.9 Outdoor routing of cables.........................................................................................................A-18
A.3 Lightning and Surge Voltage Protection ..................................................................................A-18
A.3.1 Overview ..................................................................................................................................A-18
A.3.2 Lightning protection zone concept ...........................................................................................A-19
A.3.3 Rules for the transition point between lightning protection zones 0 <-> 1 ...............................A-21
A.3.4 Rules for the transition point between lightning protection zones 1 <-> 2 and higher.............A-22
A.3.5 Example: Surge protection circuit for networked S7-300 PLCs...............................................A-26
A.3.6 How to Protect Digital Output Modules against Inductive Surge Voltage................................A-28
A.4 Safety of Electronic Control Equipment ...................................................................................A-30
Glossary ..................................................................................................................................... Glossary-1
Index................................................................................................................................................ Index-1

Siemens Simatic S7-300 CPU 31xC Series Specifications

General

Series	S7-300 CPU 31xC
Power Supply	24 V DC
Communication Interfaces	MPI, PROFIBUS DP
Programming Languages	LAD, STL, FBD, SCL
Operating Temperature	0°C to +60°C
Memory	48 KB - 512 KB
Dimensions	40 x 125 x 130 mm (varies by model)