Table of Contents

FOREWORD
INTRODUCTION
1 Scope
2 Reference documents
3 Definitions
4 General EMC considerations on installation of
    earthing and cabling systems
    4.1 General
    4.2 EMC and safety (insulation) installation
          requirements
    4.3 Equipment and installation ports
5 Earthing and bonding
    5.1 Requirements concerning safety
    5.2 Requirements concerning EMC
    5.3 Design of the earthing system
6 Bonding
    6.1 General
    6.2 Bonding straps
    6.3 Connections
    6.4 Bonding of specific equipment
    6.5 Procedures for users
7 Cables and wires
    7.1 General
    7.2 Differential and common mode circuit, transfer
          impedance Zt
    7.3 Set of EMC rules for cable and wire installation
    7.4 Types of cables and their use with regard to
          EMC
    7.5 Types of parallel-earthing conductor (PEC)
    7.6 Connecting and earthing of cables and parallel
          earthed conductors
    7.7 General routing of cables
    7.8 Cable bundles
    7.9 Cables serving power ports
    7.10 Cables serving signal and control ports
8 Additional interference mitigation methods
    8.1 Common-mode ferrite choke
    8.2 Electrical separation
9 Measuring and testing methods
    9.1 Earthing and bonding
    9.2 Cables and installation
Figures
1 Demonstration of the fallacy of the 'equipotentiality'
    concept as a universal rule
2 Schematic plan view of a typical earth electrode
3 Misconception of 'dedicated', 'independent', or
    'isolated' earth electrodes
4 The concept of a single earth electrode
5 Recommended configuration for the earth electrodes
    and earthing network
6 Loops involving signal cables and earthing network
7 A three-dimensional schematic of the recommended
    approach for the earthing network
8 General principles for bonding of various apparatus
    or systems to the earthing network
9 Simplified representation of a bonding strap
10 A more realistic representation of an installed
    bonding strap
11 Typical bonding straps
12 Relative inductance of flat and round conductors
13 Relative inductance of round, flat and double
    bonding straps
14 Example of protected removable connection of a bonding
    strap
15 Example of optimal bonding of a shielded cable to the
    enclosure
16 Schematic of interconnected chassis
17 Differential mode and common mode circuits with
    bonding strips and signal cables
18 Effect of the configuration of a parallel-earthing
    conductor on the transfer impedance
19 Slits in conduits and cable trays
20 Recommended configuration for cable trays with branches
21 Recommended cable positions parallel to an
    H-shaped beam from the EMC point of view
22 Penetration of a shielded cable through an
    enclosure wall
23 Tray with partition
24 Example of stacking for conduits or trays
25 Topology of circuits containing switches
26 Undesirable connection of a coaxial cable
27 Typical implementations of common-mode ferrite chokes
28 Limitations in the effectiveness of an isolation
    transformer
29 Parasitic coupling at high frequencies
Annexes
A Examples of earthing systems and cable implementation
B Applying cable theory to enhance EMC
C Benefits of additional conductors parallel to a
    cable
D Bibliography
Annex figures
A.1 Example of topology for a hybrid earthing system
A.2 EMC cabinet for the protection of sensitive
    electronics
A.3 Earthing system for a drive with converter and
    associated electronics
A.4 Earthing configuration for a power supply system with
    associated electronics
A.5 Initial arrangement of the power and control cables
A.6 Improved design with appropriate shield connections
B.1 Unbalanced transport of signals
B.2 Behaviour of Zt as function of frequency for several
    coaxial cable configurations
B.3 Unbalanced transmission system connected to earth
    at one end
B.4 Balanced transmission system
B.5 Current paths in a coaxial cable
B.6 Differential-mode voltage induced by a magnetic
    field in a cable with braided shield
B.7 Currents in the outer conductor of a coaxial cable
B.8 A two-lead cable perturbed by a nearby lead at
    the voltage Uext
C.1 Coaxial cables with parallel-earthing conductors
C.2 A coaxial with two outer conductors
C.3 Transfer impedances in a shielded balanced pair
C.4 Example of transfer impedance for an aluminium
    conduit as a function of frequency
C.5 Mutual inductance and magnetic field for a conduit or
    cable tray
C.6 Insulated covers over a conduit

Abstract

Gives guidelines for earthing and cabling of electrical and electronic systems and installations aimed at ensuring electromagnetic compatibility (EMC) among electrical and electronic apparatus or systems. Addresses earthing practices and with cables used in industrial, commercial and residential installations. Intended to be used by installers and users and manufacturers of sensitive electrical or electronic installations and systems, and equipment having high emission levels for degrading the overall electromagnetic (EM) environment. Mainly applicable to new installations, but may apply to extensions or modifications to existing facilities.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	International Electrotechnical Committee
Pages
ISBN
Committee	TC 77B