Schneider Electric - Electrical installation guide 2009
Q
© Schneider Electric - all rights reserved
Chapter Q
EMC guidelines
Contents
Electrical distribution
Q2
Earthing principles and structures
Q3
Implementation
Q5
3.1 Equipotential bonding inside and outside buildings
Q5
3.2 Improving equipotential conditions
Q5
3.3 Separating cables
Q7
3.4 False floor
Q7
3.5 Cable running
Q8
3.6 Implementation of shielded cables
Q11
3.7 Communication networks
Q11
3.8 Implementation of surge arrestors
Q12
3.9 Cabinet cabling
Q15
3.10 Standards
Q15
Coupling mechanisms and counter-measures
Q6
4.1 General
Q16
4.2 Common-mode impedance coupling
Q17
4.3 Capacitive coupling
Q18
4.4 Inductive coupling
Q19
4.5 Radiated coupling
Q20
Wiring recommendations
Q22
5.1 Signal classes
Q22
5.2 Wiring recommendations
Q22
2
3
4
5
Schneider Electric - Electrical installation guide 2009
Q - EMC guidelines
Q2
© Schneider Electric - all rights reserved
Electrical distribution
The system earthing arrangement must be properly selected to ensure the
safety of life and property. The behaviour of the different systems with respect
to EMC considerations must be taken into account. Figure Q below presents a
summary of their main characteristics.
European standards (see EN 50174-2 § 6.4 and EN 50310 § 6.3) recommend the
TN-S system which causes the fewest EMC problems for installations comprising
information-technology equipment (including telecom equipment).
Fig. Q1 : Main characteristics of system earthing
When an installation includes high-power equipment (motors, air-conditioning, lifts,
power electronics, etc.), it is advised to install one or more transformers specifically
for these systems. Electrical distribution must be organised in a star system and all
outgoing circuits must exit the main low-voltage switchboard (MLVS).
Electronic systems (control/monitoring, regulation, measurement instruments, etc.)
must be supplied by a