GB/T 16895.3-2024 Low-voltage electrical installations Part 5-54: Selection and erection of electrical equipment - Earthing arrangements and protective conductors
541 General
541.1 Scope
This document addresses the earthing arrangements and protective conductors including protective bonding conductors in order to satisfy the safety of the electrical installation.
This document also includes requirements regarding earthing and equipotential bonding for information and communication technology (ICT) with the aim of:
—— reducing the risk of electrical hazards for correct operation of these devices and the
information and communication technology wiring;
—— providing the telecommunication systems with a reliable signal reference plane that can improve resistance to electromagnetic interference (EMI) by reference to ISO/IEC 30129.
Note: Examples of information and communication technology (ICT) include:
—— DC supply networks (and systems) for supplying power to ICT equipment within a building;
—— star-shaped private automatic branch exchanges (PABX) or their equipment;
—— local area (communication) networks (LANs);
—— fire and intruder alarms communication systems;
—— building automation systems, e.g. direct digital control systems;
—— systems for computer-aided manufacturing (CAM) and other computer-aided services;
—— broadcast and communication technology.
541.2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 16895.10-2021 Low-voltage electrical installations - Part 4-44: Protection for safety - Protection against voltage disturbances and electromagnetic disturbances (IEC 60364-4-44:2018, IDT)
Note: There is no technical difference between the content referenced in GB/T 16895.10-2021 and the content referenced in (IEC 60364-4-44:2007).
GB/T 16895.18-2010 Electrical installations of buildings - Part 5-51: Selection and erection of electrical equipment - Common rules (IEC 60364-5-51:2005, IDT)
GB/T 16895.21-2020 Low-voltage electrical installations - Part 4-41: Protection for safety - Protection against electric shock (IEC 60364-4-41:2017, IDT)
Note: There is no technical difference between the content referenced in GB/T 16895.21-2020 and the content referenced in IEC 60364-4-41:2005
GB/T 17045-2020 Protection against electric shock - Common aspects for installations and equipment (IEC 61140:2016, IDT)
Note: There is no technical difference between the content referenced in 17045-2020 and the content referenced in IEC 61140:2001.
GB/T 21714.3-2015 Protection against lightning - Part 3: Physical damage to structures and life hazard (IEC 62305-3:2010, IDT)
IEC 60417 Graphical symbols for use on equipment
Note: GB/T 5645.1-2009, Appliances couplers for household and similar general purposes.Part 1: General requirements (IEC 60417 Datebase:2007-01, MOD)
GB/T 5465.2-2023 Graphical symbols for use on electrical equipment - Part 2: Graphical symbols (IEC 60417 Datebase:2023-03, IDT)
IEC 60445 Basic and safety principles for man-machine interface, marking and identification - Identification of equipment terminals, conductor terminations and conductors
Note: GB/T 4026-2019, Basic and safety principles for man-machine interface,marking and identification - Identification of equipment terminals,conductor terminations and conductors (IEC 60445:2017, IDT)
IEC 60724 Short-circuit temperature limits of electric cables with rated voltages of 1 kV (Um =1.2 kV) and 3 kV (Um = 3.6 kV)
IEC 60909-0 Short-circuit currents in three-phase a.c. systems - Part 0: Calculation of currents
Note: GB/T 15544.1-2023, Short-circuit current calculation in three-phase a.c. systems - Part 1: Calculation of currents (IEC 60909-0:2016, MOD)
IEC 60364-4-41 Low voltage electrical in-stallations - Part 4-4l: Protection for safety-Protection against electric shock
Note: GB/T 16895.21-2020, Low-voltage electrical installations - Part 4-41: Protection for safety - Protection against electric shock (IEC 60364-4-41:2017, IDT)
IEC 60364-4-44 Low-voltage electrical installations - Part 4-44: Protection for safety - Protection against voltage disturbances and electromagnetic disturbances
Note: GB/T16895.10-2021, Low-voltage electrical installations - Part 4-44: Protection for safety - Protection against voltage disturbances and electromagnetic disturbances (IEC 60364-4-44:2018, IDT)
IEC 60364-5-51 Low-voltage electrical installations - Part 4-44: Protection for safety - Protection against voltage disturbances and electromagnetic disturbances
Note: GB/T 16895.18-2010, Electrical installations of buildings - Part 5-51: Selection and erection of electrical equipment - Common rules (IEC 60364-5-51:2005, IDT)
IEC 60949 Calculation of thermally permissible short-circuit currents, taking into account non-adiabatic heating effect
Note: GB/T 42397-2023, Calculation of thermally permissible short-circuit currents, taking into account non-adiabatic heating effects (IEC 60949-0:1988,IDT)
IEC 61140 Protection against electric shock - Common aspects for installation and equipment
Note: GB/T 17045-2020, Protection against electric shock - Common aspects for installations and equipment (IEC 61140:2016, IDT)
IEC 61439-1 Low-voltage switchgear and controlgear assemblies - Part 1: General rules
Note: GB/T 7251.1-2023, Low-voltage switchgear and controlgear assemblies - Part 1: General rules (IEC 61439-1:2020, IDT)
IEC 61439-6 Low-voltage switchgear and controlgear assemblies - Part 6: Busbar trunking systems(busways)
IEC 61439-2 Low-voltage switchgear and controlgear assemblies - Part 2: Power switchgear and controlgear assemblies
Note: GB/T 7251.2-2023, Low-voltage switchgear and controlgear assemblies - Part 2: Power switchgear and controlgear assemblies (IEC 61439-2:2020, IDT)
IEC 61534-1 Powertrack systems - Part 1: General requirements
Note: GB/T 34130.1-2017, Powertrack systems - Part 1: General requirements (IEC 61534-1:2014, MOD)
IEC 62305 (all parts) Protection against lightning
Note: GB/T 21714 (all parts), Protection against lightning [IEC 62305 (all parts)]
541.3 Terms and definitions
For the purposes of this document, the terms and definitions of IEC 61140, together with the following definitions, apply.
Definitions used for earthing arrangements, protective conductors and protective bonding
conductors are illustrated in Annex B and listed below:
541.3.1
exposed-conductive-part
conductive part of equipment which can be touched and which is not normally live, but which can become live when basic insulation fails
[SOURCE: GB/T 2900.71-2008, 826-12-10]
541.3.2
extraneous-conductive-part
conductive part not forming part of the electrical installation and liable to introduce an electric potential, generally the electric potential of a local earth
[SOURCE: GB/T 2900.71-2008, 826-12-11]
541.3.3
earth electrode
conductive part, which may be embedded in the soil or in a specific conductive medium, e.g. concrete, in electrical contact with Earth
[SOURCE: GB/T 2900.71-2008, 826-13-05, modified]
541.3.4
concrete-embedded foundation earth electrode
earth electrode embedded in concrete of a building foundation, generally in the form of a
closed loop
[SOURCE: GB/T 2900.71-2008, 826-13-08, modified]
541.3.5
soil-embedded foundation earth electrode
earth electrode buried in the soil under a building foundation, generally in the form of a closed loop
[SOURCE: GB/T 2900.71-2008, 826-13-08, modified]
541.3.6
protective conductor
conductor provided for purposes of safety, for example protection against electric shock
[SOURCE: GB/T 2900.71-2008, 826-13-22]
Note: Examples of a protective conductor include a protective bonding conductor, a protective earthing conductor and an earthing conductor when used for protection against electric shock.
541.3.7
protective bonding conductor
protective conductor provided for protective-equipotential-bonding
[SOURCE: GB/T 2900.71-2008, 826-13-24]
541.3.8
earthing conductor
conductor which provides a conductive path, or part of the conductive path, between a given point in a system or in an installation or in equipment and an earth-electrode network
[SOURCE: GB/T 2900.71-2008, 826-13-12]
Note: For the purposes of this part of IEC 60364, an earthing conductor is the conductor which connects the earth electrode to a point in the equipotential bonding system, usually the main earthing terminal.
541.3.9
main earthing terminal
main earthing busbar
terminal or busbar which is part of the earthing arrangement of an installation and enabling the electrical connection of a number of conductors for earthing purposes
[SOURCE: GB/T 2900.71-2008, 826-13-15]
541.3.10
protective earthing conductor
protective conductor provided for protective earthing
[SOURCE: GB/T 2900.71-2008, 826-13-23]
541.3.11
functional earthing
earthing a point or points in a system or in an installation or in equipment, for purposes other than electrical safety
[SOURCE: GB/T 2900.71-2008, 826-13-10]
541.3.12
earthing arrangement
all the electrical connections and devices involved in the earthing of a system, installation or an equipment
[SOURCE: GB/T 2900.73-2008, 195-02-20]
541.3.13
functional earthing conductor
conductor provided for functional earthing
[SOURCE: GB/T 2900.71-2008, 826-13-28, modified - In the definition, "earthing conductor" replaced with "conductor".]
541.3.14
main functional earthing terminal; MFET
main functional earthing busbar
terminal or busbar, which is part of the functional earthing arrangement of an electrical installation, enabling the electric connection of a number of conductors for functional earthing purposes
541.3.15
functional-equipotential-bonding
equipotential bonding for reasons other than electrical safety
[SOURCE: GB/T 2900.71-2008, 826-13-21, modified - "operational reasons other than safety" replaced with "reasons other than electrical safety".]
541.3.16
protective-equipotential-bonding
equipotential bonding for the purposes of electrical safety
[SOURCE: GB/T 2900.71-2008, 826-13-20, modified - "electrical" added.]
541.3.17
equipotential bonding
provision of electric connections between conductive parts, intended to achieve equipotentiality
[SOURCE: GB/T 2900.71-2008, 826-13-19]
541.3.18
protective earthing
earthing for purposes of electrical safety
[SOURCE: GB/T 2900.71-2008, 826-13-09, modified - "a point or points in a system or in an installation or in equipment" deleted.]
541.3.19
functional bonding conductor
conductor provided for functional-equipotential-bonding
[SOURCE: GB/T 2900.71-2008, 826-13-29]
542 Earthing arrangements
542.1 General requirements
542.1.1 The earthing arrangements may be used jointly or separately for protective and functional purposes according to the requirements of the electrical installation. The requirements for protective purposes shall always take precedence.
Contents
Foreword I
Introduction III
541 General
541.1 Scope
541.2 Normative references
541.3 Terms and definitions
542 Earthing arrangements
542.1 General requirements
542.2 Earth electrodes
542.3 Earthing conductors
542.4 Main earthing terminal
543 Protective earthing conductors
543.1 Minimum cross-sectional areas
543.2 Types of protective conductors
543.3 Electrical continuity of protective earthing conductors
543.4 PEN, PEL or PEM conductors
543.5 Combined protective and functional earthing conductors
543.6 Currents in protective earthing conductors
543.7 Reinforced protective earthing conductors for protective earthing conductor currents exceeding 10 mA
543.8 Arrangement of protective earthing conductors
544 Protective bonding conductors
544.1 Protective bonding conductors for connection to the main earthing terminal
544.2 Protective bonding conductors for supplementary bonding
545 Functional earthing and functional-equipotential-bonding for Information and communication technology equipment and systems (ICT)
545.1 Functional-equipotential-bonding for ICT
545.2 Main functional earthing terminal (MFET)
545.3 Equipotential bonding ring conductors
Annex A (Normative) Method for deriving the factor k in 543.1.2 (see also IEC 60724 and IEC 60949)
Annex B (Informative) Example of earthing arrangements and protective conductors
Annex C (Informative) Erection of concrete-embedded foundation earth electrodes
Annex D (Informative) Erection of soil-embedded earth electrodes
Annex E (Informative) List of notes concerning certain countries
Bibliography
