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How is the grounding sign indicated in electrical installations. grounding

GOST R 50571.10-96
(IEC 364-5-54-80)

UDC 696.6:006.354

Group E08

ELECTRICAL INSTALLATIONS OF BUILDINGS

Part 5
SELECTION AND INSTALLATION OF ELECTRICAL EQUIPMENT

Chapter 54
GROUNDING DEVICES AND PROTECTIVE CONDUCTORS
Electrical installations of buildings. Part 5. Selection and erection of electrical equipment.
Chapter 54

OKS 27020; 29020
OKSTU 3402

Introduction date 1997-01-01

Foreword

1. PREPARED AND INTRODUCED by the Technical Committee for Standardization TC 337
"Electrical equipment of residential and public buildings».

2. ADOPTED AND PUT INTO EFFECT by the Decree of the State Standard of Russia dated July 10
1996 No. 449.

3. This standard, with the exception of table 54D, contains the full authentic text
international standard IEC 364-5-54 (1980) “Electrical installations of buildings. Part 5. Choice
and installation of electrical equipment. Chapter 54. Grounding devices and protective conductors "and
Amendment No. 1 (July 1982) to this standard.

4 INTRODUCED FOR THE FIRST TIME

5 REVISION

Introduction

This standard is part of a set of state standards for
electrical installations of buildings developed on the basis of the standards of the International
Electrotechnical Commission IEC 364 "Electrical installations of buildings".
The requirements of the standard should be taken into account when developing and revising standards, norms and
rules for the device, testing, certification and operation of electrical installations.
For the convenience of using the standard when referring to it in another normative
documentation related to the IEC 364 family of standards in this standard
the numbering of sections and paragraphs adopted in the IEC 364-5-54-80 standard has been retained.

1 area of use

This standard specifies requirements for earthing devices and protective
conductors of electrical installations.
The scope of the standard is according to GOST 30331.1/GOST R 50571.1.
The requirements of this standard are mandatory.

This standard uses references to the following standards:
GOST 10434-82. Electrical contact connections. Classification. General
technical requirements
GOST 22782.0-81. Explosion-proof electrical equipment. General technical
requirements and test methods
GOST 30331.1-95 (IEC 364-1-72, IEC 364-2-70) / GOST R 50571.1-93 (IEC 364-1-72, IEC
364-2-70) Electrical installations of buildings.

Key points

GOST 30331.2-95 (IEC 364-3-93) / GOST R 50571.2-94 (IEC 364-3-93) Electrical installations
buildings. Part 3. Key Features
GOST 30331.3-95 (IEC 364-4-41-92)/GOST R 50571.3-94 (IEC 364-4-41-92)
Electrical installations of buildings. Part 4. Security requirements. Defence from
defeat electric shock.

541. General requirements
541.1. Performance characteristics grounding device must meet
safety requirements and ensure the normal operation of the electrical installation.

542. Grounding
542.1. Grounding devices.
542.1.1. Grounding devices can be combined or separate for
protective or functional purposes, depending on the requirements
electrical installation, house grounding
542.1.2. Grounding devices must be selected and installed in such a way that
to:
- the spreading resistance value of the grounding device corresponded to
requirements for ensuring the protection and operation of the installation during the period of operation;
- the flow of earth fault currents and leakage currents did not create a hazard, in particular
in relation to heating, thermal and dynamic resistance;
- the necessary strength or additional mechanical protection was provided in
depending on the given external factors according to GOST 30331.2/GOST R 50571.2.
boiler grounding
542.1.3. Care must be taken to prevent damage to metal
parts due to electrolysis.
542.2. Grounding.
542.2.1. As grounding conductors, those in contact can be used.
with earth:
- metal rods or pipes;
- metal strips or wire;
- metal plates, plates or sheets;
- foundation ground electrodes;
- steel reinforcement of reinforced concrete;
Note. Possibility of use as grounding conductors
stressed reinforcement in reinforced concrete should be substantiated by calculation data;
- steel water pipes in the ground, subject to the conditions of 542.2.5;
- other underground structures that meet the requirements of 542.2.6.
Note. The effectiveness of the earth electrode depends on the specific ground conditions, and
therefore, depending on these conditions and the required value of spreading resistance
the number and design of earth electrodes must be selected. Resistance value
earth electrode spreading can be calculated or measured.
542.2.2. The type of earth electrodes and the depth of their laying must be such that drying and
freezing of the soil did not cause an excess of the value of the resistance to spreading of the ground electrode
over the required value.
542.2.3. The material and design of earth electrodes must be resistant to corrosion.
542.2.4. When designing grounding devices, one should take into account the possible
an increase in their resistance to spreading due to corrosion.
542.2.5. Metal water pipes can be used as natural
grounding devices, subject to obtaining permission from the water supply organization, and
also provided that appropriate measures are taken to notify operating personnel
electrical installations about planned changes in the water supply system.
Note. It is desirable that the reliability of grounding devices does not depend on other
systems.
542.2.6. Metal pipes of systems other than those mentioned in 542.2.5
(e.g. with flammable liquids or gases, central heating systems, etc.), not
must be used as grounding conductors for protective earthing.
Note. This requirement does not preclude their inclusion in the adjustment system.
potentials in accordance with GOST 30331.3/GOST R 50571.3.
542.2.7. Lead and other metallic sheaths of cables not subject to
destruction by corrosion, can be used as ground electrodes

with the permission of the cable owner and provided that appropriate measures are taken to notify
operating personnel of the electrical installation about any changes regarding cables,
which may affect its suitability for use as a ground electrode.
542.3. Grounding conductors.
542.3.1. Earthing conductors shall comply with the requirements of 543.1 and, if they
laid in the ground, their cross section must correspond to the values \u200b\u200bspecified in Table. 54A.
Table 54A - Smallest dimensions grounding conductors laid in the ground

542.3.2. The grounding conductor must be securely connected to the grounding conductor and have
with it an electrical contact that meets the requirements of GOST 10434. Using
clamps, they must not damage either the earthing conductor (e.g. pipes) or the earthing
conductors.
542.4. Main earth clamps or bars.
542.4.1. Each installation must have a main earth terminal or
bus and to it (or to it) must be attached:
- grounding conductors;
- protective conductors;
- conductors main system potential equalization (see Appendix B);
- conductors of working grounding (if it is required).
542.4.2. In an accessible place, the possibility of a connector (disconnection) should be provided.
grounding conductors to measure the spreading resistance of the grounding device.
This capability can be provided by using the main earth terminal or
tires. The design of the clamp must allow its release only by means of
tool, be mechanically strong and ensure the continuity of the electrical circuit.

543. Protective conductors
Note. For the requirements for protective conductors for potential equalization systems, see
in section 547.
543.1. Smallest areas cross section protective conductors must be:
- calculated in accordance with 543.1.1 or
- selected in accordance with 543.1.2.
In both cases, the requirements of 543.1.3 should be taken into account.
Note. The earthing terminal of the installation equipment must be capable of
connection of protective conductors.
543.1.1. The cross-sectional area of the protective conductor S, mm2, must not be
less than the value defined by the following formula (only applies to time
shutdown no more than 5 s):

where I is the effective value of the short circuit current flowing through the device
protection with negligible transient resistance, A;
t - time delay of the disconnecting device, s;
Note. Consideration should be given to the current limitation by the circuit resistance and the limiting
capacity (Joule integral) of the protection device.
k - coefficient, the value of which depends on the material of the protective conductor, its
insulation and initial and final temperatures. (The formula for calculation is given in Appendix A).
k value for protective conductors in various conditions shown in tables 54B-54E. If the formula results in a non-standard cross-section,
use conductors of the nearest larger standard section.
Notes
1. It is necessary that the section calculated in this way correspond to the conditions
determined by the resistance of the circuit "phase - zero".
2. Meaning maximum temperature for electrical installations in hazardous areas
set according to GOST 22782.0.
3. Observe the maximum permissible clamp temperatures.

543.1.2. The cross section of protective conductors must not be less than the values given in
table 54F. In this case, it is not necessary to check the section for compliance with 543.1.1.
If, during the calculation, a cross-section value is obtained that differs from that given in the table, one should
select the nearest higher value from the table.

The values in table 54F are only valid if the protective conductors
made of the same material as the phase conductors. Otherwise, sections
protective conductors are selected so that their conductivity is equal to
conductivity obtained as a result of applying the table.
543.1.3. In all cases, the cross section of protective conductors not included in the cable
must be at least:
2.5 mm2 - in the presence of mechanical protection;
4 mm2 - in the absence of mechanical protection.
Note. When selecting and laying protective conductors, external
influencing factors according to GOST 30331.2/GOST R 50571.2.
543.2. Types of protective conductors.543.2.1. The following can be used as protective conductors:
- conductors of multicore cables;
- insulated or uninsulated wires in a common sheath with phase wires;
- permanently laid uninsulated or insulated conductors;
- metallic sheaths of cables, e.g. aluminum cable sheaths, screens,
armor of some cables;
- metal pipes or metal sheaths for conductors;
- some conductive elements that are not part of the electrical installation (third-party
conductive parts), e.g. metal building construction buildings and structures
industrial purposes (crane tracks, galleries, elevator shafts, etc.).
543.2.2. Shells or frames of prefabricated devices or enclosures
complete busbars, available as part of the installation, can be used as
protective conductors, provided that they simultaneously satisfy the following
requirements:
a) the electrical continuity of the circuit is carried out in such a way that it is ensured
protection against mechanical, chemical and electrochemical damage;

c) they must provide the possibility of connecting other protective conductors in
any place provided for it.
543.2.3. Metal protective covers (non-insulated or insulated)
some wiring systems, in particular, mineral insulated cable sheaths, and
also metal pipes of electrical wiring and electrical boxes can be
used as protective conductors for the respective circuits, if they
simultaneously meet the requirements of 543.2.2 a, b. Use of other pipes and casings in
as protective conductors is not allowed.
543.2.4. Third party conductive parts (HFCs) can be used as protective
conductors if they simultaneously meet the following requirements:
a) the electrical continuity of the circuit is ensured either by their design, or
appropriate compounds that protect it from mechanical, chemical and
electrochemical damage;
b) their conductivity is not less than that given in 543.1;
c) their dismantling is not possible unless measures are taken to maintain continuity
circuit and its conductivity;
d) they are designed or, if necessary, adapted for that purpose.
It is allowed to use metal water pipes with permission
organization responsible for the operation of the water supply. Use of system pipes
gas supply as protective conductors is prohibited.
543.2.5. The use of the HFC as a PEN conductor is prohibited.
543.3. Ensuring electrical continuity of protective conductors.
543.3.1. Protective conductors must be suitably protected against
mechanical and chemical damage, as well as from electrodynamic forces.
543.3.2. Protective conductor connections must be accessible for inspection and
tests, except for joints filled with compound or sealed.
543.3.3. It is forbidden to connect switching devices in the circuit of protective conductors,
however, there may be connections that can be disassembled with a tool
for testing purposes.
543.3.4. In the case of using a ground continuity monitor
it is forbidden to turn on its winding in series (in a cut) with a protective conductor.
543.3.5. Exposed conductive parts of the equipment must not be used as
protective conductors for other electrical equipment, except for cases
provided for in 543.2.2.

544. Protective earth
Note. Protection requirements for TN systems (tn-c-s grounding system), TT and IT - according to GOST 30331.3 / GOST R
50571.3.
544.1. Protective conductors used in conjunction with protection devices
overcurrent. When using an overcurrent protection device to protect against shock
electric current, it is necessary to lay protective conductors in a common sheath with
phase conductors or in close proximity to them.
544.2. Earthing switches and protective conductors for tripped protective devices
in the event of voltage fluctuation or failure.
544.2.1. An additional grounding conductor, not connected
electrically with other grounded metal parts such as
metal structures, metal pipes, metal sheaths of cables. This condition
is considered fulfilled if the auxiliary earthing switch is installed on a certain
away from earthed metal parts.
544.2.2. The earth conductor coming from the auxiliary earth conductor must be
insulated to prevent contact with the protective conductor of the system
protective earth or with connected to it or other conductive parts that
may be in contact with the protective earth system.
Note. This requirement must be observed to avoid accidental shunting.
voltage sensor.
544.2.3. The protective conductor must only be connected to the housings of that electrical
equipment that must be switched off in the event of a protective device being activated.

545. Working ground
545.1. General requirements.
Working grounding must be carried out in such a way as to ensure
normal operation of electrical equipment, as well as normal and reliable operation
electrical installations.

546. Combined grounding device
for working and protective earthing
546.1. General requirements.
Where grounding is required for both protection and normal operation
electrical installations, first of all, the requirements for protective measures should be observed.
546.2. PEN conductors.
546.2.1. In TN systems for permanently laid cables with an area
of a cross section of at least 10 mm2 for copper or 16 mm2 for aluminium, a single core may be used as a PEN conductor, provided that the part in question
installation is not protected by residual current devices that respond to
differential current.
546.2.2. To avoid stray currents, the insulation of the PEN conductor must be
designed for the highest voltage that can be applied to it.
Note. The PEN conductor does not need to be insulated inside complete devices
control and distribution of electricity.
546.2.3. In cases where, starting from any installation point, zero working and zero
protective conductors are separated, it is forbidden to combine these conductors beyond this point along
the course of energy. Separate clamps or busbars must be provided at the separation point
zero working and protective conductors. The PEN conductor must be connected to a terminal
for the protective conductor.

547. Conductors of the potential equalization system
547.1. Smallest cross-sectional areas.
547.1.1. The main conductors of the potential equalization system.
The cross section of the main conductor of the potential equalization system must be at least
half of the largest section of the protective conductor of the installation, but not less than 6 mm2. However, not
it is required to use conductors with a cross section of more than 25 mm2 in copper or equivalent, if
the conductor is made of another metal.
547.1.2. Additional conductors of the potential equalization system.
The cross section of the additional conductor of the potential equalization system connecting two
exposed conductive parts of electrical equipment that are not normally energized,

must be at least the cross section of the smallest of the protective conductors,
connected to these parts.
The cross section of the additional conductor of the potential equalization system connecting
grounded parts of electrical equipment and metal constructions construction and
for industrial purposes, there must be at least half the cross section of the protective conductor
electrical equipment connected to this grounding part.
Additional conductors of the potential equalization system should, if necessary,
meet the requirements of 543.1. Communication for potential equalization can be provided
or metal structures for construction and industrial purposes, or
additional conductors, or a combination of both.
547.1.3. Shunting of flowmeters.
In the case of using the building's water pipes as grounding or protective
conductors, it is necessary to provide shunting of flowmeters using
conductor of the correct cross section, depending on whether it is used as
protective conductor of the potential equalization system or working ground conductor.

APPENDIX A
(mandatory)

Recently, the issues of proper grounding have become very discussed. This is due to the fact that in practice it is often necessary to solve non-standard problems, and their solution requires the use of various methods. In this article we will consider the main provisions of the existing regulations on this issue.

Existing grounding standards

Today, there are a number of regulations designed to regulate the grounding device. Below we briefly list them.

Rules for the installation of electrical installations (PUE)
GOST 50571.3-94, requirements for ensuring safety against electric shock
GOST R 12.1.019-2009, electrical safety
GOST R 50571.29-2009, selection and installation of electrical equipment.
GOST, requirements for special installations.

Let us immediately make a reservation that the most significant documents. Also, the list did not include the standards of the International Electrotechnical Commission (IEC) for special electrical installations.

The presented norms are always used for the equipment of one or another grounding system.

GOST grounding requirements

In this section, we will consider the basic requirements for grounding according to GOST.

Protective grounding or zeroing is designed to ensure the safety of people and other living beings when touching metal objects and electrical appliances. In this case, all elements of installations that can come into direct contact with a person must be grounded.
It is produced by connecting the metal elements of electrical installations or equipment to the ground, or its other analogue.
Zeroing is performed by electrically connecting metal elements to a point grounded using a neutral conductor.
Preference is given to natural grounding, while the allowable voltage must be provided at any time of the year.
Compliance of grounding devices with all the above requirements is established during the commissioning of an electrical structure, and is also checked during its operation.

Rules for electrical installations (PUE) grounding

In this chapter, we will point by point the main provisions of the grounding PUE.

The resistance of the device to which the neutrals of the generator or transformer are connected should be approximately 8 ohms, the voltage should be 220 V, regardless of the season. This should be provided by natural grounding
The resistance of the earth electrode, which is located near the neutral of the generator or transformer, should be about 60 ohms if the voltage in the network is 220 V.
In this case, re-grounding of the PEN-conductor is carried out without fail at the ends of the overhead lines, as well as at their branches, the length of which is not more than 250 m.
The total resistance of grounding conductors for repeated grounding should be no more than 20 ohms at a voltage of 220 V.
The earth conductor must be connected directly to the neutral of the transformer or generator.

The organization of grounding or grounding is not required if the rated voltage is up to 42 V, and the alternating voltage is 110 or less. AT.

www.autobahn.ru

Hello, dear guests of the Electrician's Notes website.

Today I will tell you about the ground loop, why it is needed and how to properly install it with your own hands.

Buying summer cottages for the construction of houses and cottages, we must obtain permission from the energy supply organization to connect a certain capacity. And at this stage, almost everyone has a problem with the wiring of the ground loop, because. in specifications it is required for the power supply of the house.

It is also necessary for reconstruction old wiring. For more information about organizing electrical wiring in your home, read the article: electrical wiring in a wooden house.

What is a ground loop?

First, let's understand what is grounding?

grounding- this is a GD (grounding device) designed for electrical connection to the "ground" of various grounded parts of electrical equipment.

Each grounding system (TN-C, TN-C-S, TN-S, TT and IT) has its own requirements for the resistance of the grounding device (follow the links of the corresponding grounding systems and get acquainted).

The resistance of the memory is very dependent on:

soil type
soil structures
soil conditions
electrode depth
number of electrodes
electrode properties

Ground loop- this is, interconnected, horizontal and vertical electrodes, which are laid at a certain depth in the soil of your site.

All the above properties of the soil are determined by its resistance to current spreading. And the lower this resistance, the better for mounting the ground loop.

Soils ideal for mounting a ground loop:

loam
high moisture clay

Soils not suitable for the installation of a ground loop:

a rock
rock

Depending on conditions environment, even the same type of soil can have different properties.

Therefore, it is necessary to consciously install the ground loop, and consider the choice of the number and length of ground electrodes on a case-by-case basis.

In this article, I will describe to you the most common and easiest way to install a ground loop. There are more modern ways, for example, a modular-pin earthing system. But we will return to them in my other articles. To not miss new releases of articles, subscribe.

Training

We choose a place for installation and installation of a grounding device.

According to the PUE (clause 1.7.111), artificial vertical and horizontal ground electrodes (electrodes) must be either copper or black or galvanized steel. Also, their surface should not be painted.

As vertical and horizontal ground electrodes (electrodes) we use:

steel corner size 50x50x5 (mm) with a cross section of 480 (sq. mm)
steel strip size 40x4 (mm) with a cross section of 160 (sq. mm)

Here are my blanks of material for mounting a ground loop for re-grounding the PEN conductor of a residential apartment building and further dividing it: into a protective conductor PE and a neutral working conductor N.

Installation of the ground loop

Now we need to take a shovel and dig a trench in the form of a triangle with dimensions (3 x 3 x 3) meters. You can dig a trench in the form of a straight line about 4-5 meters long. Recent times we do exactly that.

The trench is 0.3-0.5 meters wide and 0.5-0.8 meters deep.

We drive a steel corner (vertical ground electrodes) 2.5-3 meters long into the vertices of this triangle with a sledgehammer. Instead of a sledgehammer, you can use special drills. If your trench is dug in the form of a straight line, then we hammer vertical electrodes in the amount of 4-5 pieces every meter.

To make it easier to drive steel corners into the ground, sharpen their ends with a grinder.

We hammer the steel corners (vertical electrodes) not completely, but leave about 20 (cm). Then, using a welding machine, we weld a horizontal steel strip to our steel corners along the perimeter of a triangle or a straight line, which goes to the power electrical panel on the PE (GZSh) bus.

The conductor that connects the grounding device to the grounding part of the electrical installation (input switchgear or assembly) is called the grounding conductor.

In our example, a steel strip with dimensions of 40 x 4 (mm) is used as a grounding conductor, which meets the requirements of the PUE.

As a result, we get such a design (scheme). By the way, I forgot to say that the welding spots need to be treated with an anti-corrosion compound, for example, bitumen, and the trench should be buried with homogeneous soil.

You can do it differently, using the EIC, clause 1.7.117. We remove a horizontal grounding conductor in the form of a steel strip from the ground, and connect a conductor to it using a bolted connection, which we lay to the PE (GZSh) bus:

copper section not less than 10 sq. mm
aluminum section not less than 16 sq. mm
steel section not less than 75 sq. mm

I used a copper bus ground conductor.

zametkielectrica.ru

1 area of use

This standard specifies requirements for earthing devices and protective conductors in electrical installations.

The scope of the standard is according to GOST 30331.1/GOST R 50571.1.

The requirements of this standard are mandatory.

2. Regulatory references

GOST 10434-82. Electrical contact connections. Classification. General technical requirements

GOST 22782.0-81. Explosion-proof electrical equipment. General technical requirements and test methods

GOST 30331.1-95 (IEC 364-1-72, IEC 364-2-70) / GOST R 50571.1-93 (IEC 364-1-72, IEC 364-2-70) Electrical installations of buildings. Key points

GOST 30331.2-95 (IEC 364-3-93) / GOST R 50571.2-94 (IEC 364-3-93) Electrical installations of buildings. Part 3. Key Features

GOST 30331.3-95 (IEC 364-4-41-92) / GOST R 50571.3-94 (IEC 364-4-41-92) Electrical installations of buildings. Part 4. Security requirements. Protection against electric shock.

541. General requirements

541.1. The operational characteristics of the grounding device must meet the safety requirements and ensure the normal operation of the electrical installation.

542. Grounding

542.1. Grounding devices.

542.1.1. Grounding devices can be combined or separate for protective or functional purposes, depending on the requirements of the electrical installation.

542.1.2. Grounding devices must be selected and installed in such a way that:

The value of the spreading resistance of the grounding device met the requirements for ensuring the protection and operation of the installation during the period of operation;

The flow of earth fault currents and leakage currents did not create a hazard, in particular with regard to heating, thermal and dynamic resistance;

The necessary strength or additional mechanical protection was provided depending on the specified external factors in accordance with GOST 30331.2/GOST R 50571.2.

542.1.3. Measures must be taken to prevent damage to metal parts due to electrolysis.

542.2. Grounding.

542.2.1. As grounding conductors, those in contact with the ground can be used:

Metal rods or pipes

Metal strips or wire;

Metal plates, plates or sheets;

Foundation ground electrodes;

Steel reinforcement of reinforced concrete;

Note. The possibility of using prestressed reinforcement in reinforced concrete as grounding conductors must be justified by calculation data;

Steel water pipes in the ground under the conditions of 542.2.5;

Other underground structures meeting the requirements of 542.2.6.

Note. The effectiveness of the earth electrode depends on the specific ground conditions, and therefore, depending on these conditions and the required value of spreading resistance, the number and design of the earth electrodes must be selected. The spreading resistance value of the earth electrode can be calculated or measured.

542.2.2. The type of grounding conductors and the depth of their laying must be such that drying and freezing of the soil does not cause the spreading resistance of the grounding conductor to exceed the required value.

542.2.3. The material and design of earth electrodes must be resistant to corrosion.

542.2.4. When designing grounding devices, one should take into account the possible increase in their spreading resistance due to corrosion.

542.2.5. Metal plumbing pipes may be used as natural earthing devices, subject to obtaining permission from the water supply organization, and also provided that appropriate measures are taken to notify the operating personnel of the electrical installation of the planned changes to the plumbing system.

Note. It is desirable that the reliability of grounding devices does not depend on other systems.

542.2.6. Metal pipes of other systems than those mentioned in 542.2.5 (for example, with flammable liquids or gases, central heating systems, etc.) must not be used as earth conductors for protective earthing.

Note. This requirement does not preclude their inclusion in the potential equalization system in accordance with GOST 30331.3 / GOST R 50571.3.

542.2.7. Lead and other metallic sheaths of cables that are not susceptible to corrosion may be used as earthing conductors with the permission of the owner of the cable and provided that appropriate steps are taken to notify the operating personnel of the electrical installation of any changes to the cables that may affect its suitability for use as a grounding conductor.

542.3. Grounding conductors.

542.3.1. Grounding conductors must meet the requirements of 543.1 and, if they are laid in the ground, their cross section must correspond to the values \u200b\u200bspecified in Table. 54A.

Table 54A - The smallest dimensions of earthing conductors laid in the ground

542.3.2. The grounding conductor must be securely connected to the grounding conductor and have electrical contact with it that meets the requirements of GOST 10434. When clamps are used, they must not damage either the earth conductor (eg pipes) or the earth conductors.

542.4. Main earth clamps or bars.

542.4.1. Each installation shall have a main earthing clamp or bar and to it (or to it) shall be connected:

Grounding conductors;

Protective conductors;

Conductors of the main potential equalization system (see Appendix B);

Working ground conductors (if required).

542.4.2. In an accessible place, it should be possible to disconnect (disconnect) the grounding conductors to measure the spreading resistance of the grounding device. This capability can be provided by using the main earth clamp or bus bar. The design of the clamp must allow its disconnection only with the help of a tool, be mechanically strong and ensure the continuity of the electrical circuit.

543. Protective conductors

Note. For requirements for protective conductors for potential equalization systems, see section 547.

543.1. The smallest cross-sectional areas of protective conductors shall be:

Calculated in accordance with 543.1.1 or

Selected in accordance with 543.1.2.

In both cases, the requirements of 543.1.3 should be taken into account.

Note. The earthing terminal of the installation equipment must allow the connection of protective conductors.

543.1.1. The cross-sectional area of the protective conductor S, mm 2, must not be less than the value determined by the following formula (applies only for a trip time of not more than 5 s):

where I is the effective value of the short-circuit current flowing through the protection device with a negligible transient resistance, A;

t - time delay of the disconnecting device, s;

Note. The current limiting by the circuit resistance and the limiting capacity (Joule integral) of the protection device must be taken into account.

k - coefficient, the value of which depends on the material of the protective conductor, its insulation and the initial and final temperatures. (The formula for calculation is given in Appendix A). The k value for protective conductors under various conditions is given in tables 54B-54E.

If the formula results in a non-standard cross-section, conductors of the nearest larger standard cross-section should be used.

Note.

1. It is necessary that the cross section calculated in this way correspond to the conditions determined by the resistance of the "phase - zero" circuit.

2. The value of the maximum temperature for electrical installations in hazardous areas is set according to GOST 22782.0.

3. Observe the maximum permissible clamp temperatures.

Table 54B - Values of the factor k for insulated protective conductors not included in the cable and for bare conductors touching the sheath of cables

Note.

Table 54C - Value of the k-factor for a protective conductor included in a stranded cable

Table 54D - Value of the k-factor when using cable sheath or armor as a protective conductor

* k-values for conductors made of aluminium, lead or steel, which are not specified in IEC 364-5-54-80.

Table 54E - Factor value for bare conductors when specified temperatures do not pose a risk of damage to nearby materials

* The indicated temperatures are only permitted if they do not impair the quality of the joints.

Note. The initial temperature of the conductor is assumed to be 30°C.

543.1.2. The cross section of protective conductors must not be less than the values given in table 54F. In this case, it is not necessary to check the section for compliance with 543.1.1.

Table 54F In millimeters squared

Section of phase conductors	The smallest cross section of protective conductors
S ≤ 16 16 < S ≤ 35 S > 35	S 16 S/2

The values in table 54F are only valid if the protective conductors are made of the same material as the phase conductors. Otherwise, the cross-sections of the protective conductors are chosen so that their conductivity is equal to the conductivity obtained as a result of applying the table.

2.5 mm 2 - in the presence of mechanical protection;

4 mm 2 - in the absence of mechanical protection.

Note. When selecting and laying protective conductors, external influencing factors should be taken into account in accordance with GOST 30331.2 / GOST R 50571.2.

543.2. Types of protective conductors.

543.2.1. The following can be used as protective conductors:

Cores of multicore cables;

Insulated or uninsulated wires in a common sheath with phase wires;

Permanently routed bare or insulated conductors

Metallic cable sheaths, e.g. aluminum cable sheaths, shields, some cable armor

Metal pipes or metal sheaths for conductors;

Some conductive elements that are not part of the electrical installation (third-party conductive parts), such as metal building structures of buildings and industrial structures (crane tracks, galleries, elevator shafts, etc.).

543.2.2. Sheaths or frames of prefabricated devices or casings of complete busbar trunkings available as part of the installation may be used as protective conductors, provided that they simultaneously meet the following requirements:

a) the electrical continuity of the circuit is carried out in such a way that it is protected from mechanical, chemical and electrochemical damage;

b) their conductivity is not less than that given in 543.1

c) they must provide the possibility of connecting other protective conductors in any place provided for this.

543.2.3. Metallic protective covers (bare or insulated) of certain electrical wiring systems, in particular mineral insulated cable sheaths, as well as metal wiring pipes and electrical conduits, may be used as protective conductors for the relevant circuits if they simultaneously meet the requirements of 543.2.2 a, b. The use of other pipes and sheaths as protective conductors is not allowed.

543.2.4. Third-party conductive parts (HFCs) may be used as protective conductors if they simultaneously meet the following requirements:

a) the electrical continuity of the circuit is ensured either by their design or by appropriate connections that protect it from mechanical, chemical and electrochemical damage;

b) their conductivity is not less than that given in 543.1;

c) their dismantling is impossible unless measures are provided to preserve the continuity of the circuit and its conductivity;

d) they are designed or, if necessary, adapted for that purpose.

It is allowed to use metal water pipes with the permission of the organization responsible for the operation of the water supply. The use of pipes of the gas supply system as protective conductors is prohibited.

543.2.5. The use of the HFC as a PEN conductor is prohibited.

543.3. Ensuring electrical continuity of protective conductors.

543.3.1. Protective conductors must be adequately protected against mechanical and chemical damage as well as against electrodynamic forces.

543.3.2. Protective conductor connections shall be accessible for inspection and testing, except for connections filled with compound or sealed.

543.3.3. It is forbidden to connect switching devices in the protective conductor circuit, however, there may be connections that can be disassembled with a tool for testing purposes

543.3.4. In the case of using a device for monitoring the continuity of the ground circuit, it is prohibited to connect its winding in series (in a cut) with a protective conductor.

543.3.5. Exposed conductive parts of equipment shall not be used as protective conductors for other electrical equipment, except as provided in 543.2.2.

544. Protective earth

Note. Protection requirements for TM, TT and IT systems - according to GOST 30331.3 / GOST R 50571.3.

544.1. Protective conductors used in conjunction with overcurrent protective devices.

When using an overcurrent protective device for protection against electric shock, it is necessary to lay protective conductors in a common sheath with phase conductors or in close proximity to them.

544.2. Earthing switches and protective conductors for protection devices that operate in the event of a voltage deviation or failure.

544.2.1. An additional earthing conductor must be provided that is not electrically connected to other earthed metal parts, such as metal structures, metal pipes, metal sheaths of cables. This condition is considered to be fulfilled if the auxiliary earthing switch is installed at a certain distance from the grounded metal parts.

544.2.2. The earth conductor from the auxiliary earth conductor must be insulated to prevent it from coming into contact with the protective conductor of the protective earthing system or connected to it or other conductive parts that may be in contact with the protective earthing system.

Note. This requirement must be observed to avoid accidental shunting of the voltage sensor.

544.2.3. The protective conductor must only be connected to housings electrical equipment, which must be switched off in case of operation of the protective device.

545. Working ground

545.1. General requirements.

In the case when grounding is required both for protection and for the normal operation of the electrical installation, first of all, the requirements for protective measures should be observed.

546.2. PEN conductors.

546.2.1. In TN systems for fixed cables having a cross-sectional area of at least 10 mm 2 for copper or 16 mm 2 for aluminum, a single core may be used as a PEN conductor, provided that the part of the installation in question is not protected by residual current devices that respond to differential current.

546.2.2. To avoid stray currents, the insulation of the PEN conductor must be rated for the highest voltage that can be applied to it.

Note. The PEN conductor does not need to be insulated inside complete power distribution and control devices.

546.2.3. In cases where, starting from any point of the installation, the zero working and zero protective conductors are separated, it is forbidden to combine these conductors beyond this point along the energy course. At the separation point, it is necessary to provide separate clamps or busbars for the zero working and protective conductors. The PEN conductor must be connected to the terminal intended for the protective conductor.

547. Conductors of the potential equalization system

547.1. Smallest cross-sectional areas.

547.1. Smallest cross-sectional areas.

547.1.1. The main conductors of the potential equalization system.

The cross section of the main conductor of the potential equalization system must be at least half of the largest section of the protective conductor of the installation, but not less than 6 mm 2. However, it is not required to use conductors with a cross section of more than 25 mm 2 for copper or equivalent if the conductor is made of another metal.

547.1.2. Additional conductors of the potential equalization system.

The cross section of the additional conductor of the potential equalization system connecting two open conductive parts of electrical equipment that are not normally energized must be at least the cross section of the smallest of the protective conductors connected to these parts.

The cross section of the additional conductor of the potential equalization system connecting the grounded parts of electrical equipment and metal structures for construction and industrial purposes must be at least half the cross section of the protective conductor of electrical equipment connected to this grounding part.

Additional conductors of the potential equalization system shall, if necessary, comply with the requirements of 543.1. Communication for equalization of potentials can be provided either by metal structures for construction and industrial purposes, or by additional conductors, or by a combination of both.

547.1.3. Shunting of flowmeters.

In the case of using the building's water pipes as grounding or protective conductors, it is necessary to provide for shunting the flow meters with a conductor of the appropriate cross section, depending on whether it is used as a protective conductor of the potential equalization system or a working ground conductor.

www.zandz.ru

What is a ground loop for?

Grounding is a device of a special design that will be connected to the ground (ground). In this case, electrical appliances are included in such a connection, which in their normal state are not energized. But in case of violation of operating conditions or other reasons that led to damage to the insulation, it can occur. Therefore, it is so important to comply with the grounding standards of the ground loop.

The whole point is as follows - the current always tends to where there is the least resistance. So in the event of a violation in the equipment, current flows out to the body of the product. The equipment begins to work intermittently and gradually becomes unusable. But something else is much worse - when you touch such a surface, a person receives such a discharge that he simply dies.

But when using a - ground loop, the following will occur. The voltage will be shared between the existing circuit and the person. That's just the ground loop in this case will have less resistance. And this means that although a person will feel inconvenience, all the same, the entire main current will go through the circuit into the ground.

Important! When arranging a ground loop, it will be important to remember and observe everything necessary for arranging it with minimal resistance.

Ground loop - types and its device

Basically, metal rods are used for grounding, which play the role of electrodes. They are interconnected and deepen a sufficient distance into the ground. This design is connected to the shield installed in the house. For this, a strip of metal of the required thickness is used. (fig.2)

The very distance to which the electrode is immersed directly depends on the height of the groundwater. The higher their occurrence, the higher the grounding system. But with all this, its removal from the desired object is from one meter to ten meters. This distance is important condition and must be strictly observed.

Location of electrodes often wear uniform geometric figure. Often it is a triangle, line or square. The shape is affected by the area that must be covered and ease of installation.

Important! The grounding system is necessarily located below the level of soil freezing that exists in a particular place.

The main types of ground loops

So there are two main types of technological solutions. These are ground loops - deep and traditional.

So at traditional way the location of the electrodes is as follows - one is located horizontally, and the rest is vertical. The first electrode is a steel strip, and the second are, respectively, metal rods. All of them must have allowed values by its size.

It must be borne in mind that the place for the device of the kennel must be selected from the fact that it should be less crowded. The best for this would be shadow side with constant soil moisture.

But this ground loop has its drawbacks:

rather difficult and physically heavy device;
the metal products that make up the circuit are subject to corrosion, which not only destroys it, but will burn them to cause a deterioration in conductivity;
since it is located in the upper part of the earth, it is very dependent on environmental parameters, which can change its conductive characteristics.

The deep method is much more efficient than the traditional one. It is produced by specialized manufacturers. And it has a number of advantages:

complies with all established standards;
service life is significantly longer;
does not depend on the environment, due to the depth of occurrence;
installation is quite simple.

It must be borne in mind that after the device of any type of ground loop, it is necessary to check its compliance with all requirements and reliability. For this purpose it is necessary to invite specialized experts. They must be licensed to carry out such activities. After verification, an appropriate conclusion is issued. It is necessary to bring a passport to the ground loop, attach a test report and a permit for use to it. (Fig. 3)

Important! It is impossible to save on materials when constructing a ground loop (Fig. 4). Otherwise, his work will be completely reduced to zero.

External ground loop

This system serves as a transformer substation and is closed. Consists of a small number of electrodes. They are located vertically. Horizontal grounding, it is made, and steel strips 4 * 40 mm.

The ground loop should have a resistance of 40 m, no more, and the earth should be maximum 1000 m / m. Currently, according to the rules, you can increase the values, but not more than ten times for the ground. From this we can conclude that in order to achieve a value of 40 m, you need to make vertical installation eight electrodes of five meters. They must be made from a circle with a diameter of 16 mm. Or you can use ten three meters, when using a corner made of steel 50 * 50 mm.

The outer contour is removed from the edge of the building by more than a meter. Elements located horizontally are buried in a trench at a distance of 700 mm from the level of the soil surface. The strip has a rib.

Thus, it is clear that existing norms should be strictly guided. So contour grounding PUE reflected in chapter 1.7. It is also necessary to keep track of all changes in requirements, which can happen quite often.

Edition, revised and supplemented, with changes
Ministry of Energy of the Russian Federation

Chapters 1.1, 1.2, 1.7, 1.9, 7.5, 7.6, 7.10 are in the version of the SEVENTH EDITION (2002)... Effective from January 1, 2003... RD 153-39.2-080-01
The rules for the installation of electrical installations (PUE) apply to newly constructed and reconstructed electrical installations of permanent and alternating current voltage up to 750 kV...

Technical circular No. 11 dated 10.10.2006

About ground electrodes and ground conductors

The purpose of this circular is to clarify how to fulfill a number of requirements of chapter 1.7 of the EMP ... The circular also reflects some of the requirements for making electrical connections to grounding devices. With the release of this circular, the possibility of using an expanded, in comparison with the provisions of Chapter 1.7 of the EMP, the nomenclature of grounding electrodes and conductors presented on the Russian market is confirmed ...

Technical Circular No. 30 of 2012

On the implementation of lightning protection and grounding of overhead lines and overhead lines up to 1 kV
Association "ROSELECTROMONTAZH"

The purpose of this circular is to issue specific recommendations for the design of overhead lines and overhead lines up to 1 kV.

Technical Circular No. 31 of 2012

On the implementation of re-grounding and automatic power off at the input of individual construction objects
Association "ROSELECTROMONTAZH"

The purpose of this circular is to issue specific recommendations for ensuring protection against indirect contact in electrical installations powered by overhead lines and overhead lines up to 1 kV.

Letter 10-04/481

federal Service for Environmental, Technological and Nuclear Supervision
DEPARTMENT OF STATE ENERGY SUPERVISION

Prior to the approval of special technical regulations it is recommended to use these circulars for guidance and application when checking project documentation and commissioning new and reconstructed electrical installations.

GUIDELINES FOR DESIGN, CONSTRUCTION AND OPERATION OF GROUNDING IN INSTALLATIONS OF WIRED COMMUNICATIONS AND RADIO BROADCASTING NODES

(With changes in original scanning and processing. Version 1)
USSR Ministry of Communications, 1971

The guide covers many grounding issues: basic definitions, ground resistance calculations from simple electrodes to complex ones, methods for reducing ground resistance in difficult soils, etc...

In the course of editing after scanning the original document, a number of corrections and reductions of the material were made (at the discretion of the editor).

RD 153-39.2-080-01
Rules for the technical operation of gas stations

Adopted and put into effect by order of the Ministry of Energy of the Russian Federation of August 1, 2001 N 229. Put into effect on November 1, 2001.

Item 9. Electrical equipment, protection against static electricity, lightning protection
Subparagraphs 9 to 9.29

RD 34.21.121
Guidelines for calculating the protection zones of lightning rods and wires

RD 34.21.122-87

INSTRUCTIONS FOR THE DEVICE
LIGHTNING PROTECTION OF BUILDINGS AND STRUCTURES;
+ MANUAL TO "INSTRUCTIONS FOR THE DEVICE
LIGHTNING PROTECTION OF BUILDINGS AND STRUCTURES"
Ministry of Energy and Electrification of the USSR

Establishes a set of measures and devices to ensure the safety of people (farm animals), the protection of buildings, structures, equipment and materials from explosions, fires, destruction when exposed to lightning. The instruction is obligatory for all ministries and departments...

Letter No. 10-03-04/182 dated 01.12.2004

On the joint application of RD 34.21.122-87 and SO 153-34.21.122-2003
Office for Supervision in the Electric Power Industry of Rostekhnadzor

Design organizations have the right to use in determining the initial data and in developing protective measures the position of any of the above instructions, or a combination thereof.

RD 45.155-2000

GROUNDING AND POTENTIAL EQUALIZATION OF FOCL EQUIPMENT AT WIRED COMMUNICATION OBJECTS
Ministry of Communications of the Russian Federation

The provisions of this guideline document (RD) are mandatory for implementation at wired communication facilities being designed and reconstructed, on which the equipment of fiber-optic transmission lines (FOTL) of the backbone and zonal networks of the VSS of Russia is installed. The provisions of this RD are recommended for implementation at existing facilities ...

RD 153-34.0-20.525-00

METHODOLOGICAL INSTRUCTIONS FOR MONITORING THE STATE OF GROUNDING DEVICES OF ELECTRICAL INSTALLATIONS
RAO "UES of Russia"

Methods for monitoring and testing the GD of substations and overhead line supports, methods for checking the breakdown fuses and the phase-zero circuit (in installations up to 1000 V) during operation and upon acceptance of newly constructed or reconstructed GD are given, as well as the devices used in this...

RULES OF TECHNICAL OPERATION OF ELECTRICAL INSTALLATIONS OF CONSUMERS (PTEEP)

MINISTRY OF ENERGY OF THE RUSSIAN FEDERATION

The rules are intended to ensure the reliable, safe and rational operation of electrical installations and their maintenance in good condition ...
The rules apply to organizations, regardless of ownership and organizational and legal forms, individual entrepreneurs, as well as citizens - owners of electrical installations with voltages above 1000 V (hereinafter - Consumers) ...
The rules do not apply to electrical installations of power stations, block stations, enterprises of electrical and thermal networks operated in accordance with the rules for the technical operation of power stations and networks ...

What is protective grounding and how to arrange it

Electrician Library. Gosenergoizdat, 1959

The brochure provides basic concepts about the purpose of protective grounding in AC electrical installations with voltage up to 35 kV and their design. Are given brief information on the calculation and operation of grounding devices.

Guidelines for the design of automation, remote control and communication devices in railway transport (I-179-89)

Ministry of Railways of the USSR, GPII "Giprotranssignalvyaz", 1989
(from the collection of Mr. Preobrazhensky A.N.)

In these guidelines, the issues of designing grounding devices, grounding and grounding of stationary (station and linear) wire communication structures, radio communications and centralization control devices (EC, DC and GAC) in railway transport are considered.

Instructions for protective grounding of electromedical equipment in institutions of the USSR Ministry of Health (1973)

All-Union Scientific Research and Testing Institute of Medical Equipment (VNIIIMT)

The instruction applies to all types of electromedical devices, electromedical devices, electromedical equipment, hereinafter referred to as electromedical equipment.

National Electrical Code (NEC) 2008 Edition (USA)

Contents and Chapter 2.250 "Grounding and Bonding"
National Fire Protection Association (NFPA)

American analogue of PUE. Chapter 2.250 Describing Grounding...

ATT-TP-76416 (USA)

Grounding and Bonding for Network Facilities

Practical guide on the design, materials used and installation standards for protective earthing of telecommunications equipment.

ATT-TP-76416-001, companion document to ATT-TP-76416 (USA)

Grounding and Bonding for Network Facilities - Design Fundamentals
American Telephone and Telegraph (AT&T Inc.)

Description of the basics, explanations and explanations for the ATT-TP-76416 manual from AT&T, making it more understandable and easier to use.

ATT-TP-76403, companion document to ATT-TP-76416 (USA)

Grounding and Bonding Requirements for Internet Services Facilities
American Telephone and Telegraph (AT&T Inc.)

AT&T's practical guide to design, materials, and installation codes for protective earthing equipment in Internet service facilities.

ARMY TM 5-852-5, AIR FORCE AFR 88-19, volume 5 (USA)

TECHNICAL MANUAL. ARCTIC AND SUBARCTIC CONSTRUCTION UTILITIES….
Departments of the army and the airforce USA

Guidelines for the construction of devices (including grounding) in the Arctic and subarctic territories for the US Army and Air Force departments. Mainly used in Alaska.

MIL-HDBK-419A (USA)

MILITARY HANDBOOK. GROUNDING, BONDING AND SHIELDING FOR ELECTRONIC EQUIPMENTS AND FACILITIES
Department of Defense USA

Guidelines on grounding and protective devices for electronic devices from the US Department of Defense.

TM 5-690 (USA)

TECHNICAL MANUAL. GROUNDING AND BONDING IN COMMAND, CONTROL, COMMUNICATIONS, COMPUTER, INTELLIGENCE, SURVEILLANCE AND RECONNAISSANCE (C4ISR) FACILITIES.
Headquarters, Department of the army USA

US Army Headquarters Technical Manual for Grounding Command, Control, Communications, Computer Facilities, and Intelligence, Surveillance and Reconnaissance Facilities.

NWSM 30-4115 (USA)

Lightning Protection, Grounding, Bonding, Shielding and Surge Protection Requirements
National Weather Service

A guide to designing, purchasing, installing, and maintaining lightning protection devices for use by US National Weather Service technicians.

CNS Manual Vol. V (India)

Communication, Navigation & Surveillance manual.
Lightning & surge protection and earthing system of CNS Installations
Airport Authority of India

Grounding standards

GOST R 50571.5.54-2013/IEC 60364-5-54:2011

Low voltage electrical installations. Part 5-54. Grounding devices, protective conductors and protective conductors for equipotential bonding

This standard specifies requirements for earthing devices, protective conductors and protective potential equalization conductors used for safety purposes in electrical installations.

GOST R 50571.5.54-2011

Selection and installation of electrical equipment. Grounding devices, protective conductors and potential equalization conductors.
Federal Agency for Technical Regulation and Metrology

This standard specifies the requirements for earthing devices, protective conductors and protective potential equalization conductors used to ensure safety in electrical installations.

GOST 12.1.030-81 as amended in 2001

Electrical safety. Protective ground. Zeroing.
Gosstandart of Russia

The standard applies to protective grounding and grounding of electrical installations of direct and alternating current with a frequency of up to 400 Hz and establishes requirements for ensuring electrical safety using protective grounding, grounding ...

GOST 12.1.038-82

Electrical safety. Maximum allowable values of touch voltages and currents.

Sets the maximum allowable values of contact voltages and currents flowing through the human body, designed to design methods and means of protecting people when they interact with industrial and domestic electrical installations of direct and alternating current with a frequency of 50 and 400 Hz.

GOST R 50571.10-96 (IEC 364-5-54-80)

Grounding devices and protective conductors.
Gosstandart of Russia

GOST R 50571.21-2000 (IEC 60364-5-548-96)

Grounding devices and systems for equalizing electrical potentials in electrical installations containing information processing equipment
Gosstandart of Russia

Requirements for technical means aimed at eliminating or limiting to an acceptable level overvoltages that can cause malfunctions in information technology equipment, as well as any other electronic equipment susceptible to interference, for example, medical, laboratory, etc...

GOST R 50571.22-2000 (IEC 60364-7-707-84)

Grounding of information processing equipment.
Gosstandart of Russia

Requirements for technical means aimed at protecting against electric shock and eliminating or limiting to an acceptable level overvoltages that can cause malfunctions in information technology equipment, as well as any other electronic equipment susceptible to interference, such as medical, laboratory, etc. ...

GOST 464-79
replacement of GOST 464-68

Grounding for fixed wire communication installations, radio relay stations, radio broadcasting nodes and antennas of collective television reception systems.
USSR State Committee for Standards

It applies to fixed and linear structures of wire communication installations, radio relay stations, radio broadcasting nodes, selective railway communication installations and antennas of collective television reception systems (SKPT), for which stationary grounding devices are equipped, and establishes the resistance standards of grounding devices that ensure the normal operation of structures and installations listed above, as well as the safety of operating personnel.

GOST R 50669-94

Power supply and electrical safety of mobile (inventory) buildings made of metal or with a metal frame for street trading and public services
Gosstandart of Russia

Establishes ... technical requirements for the power supply and electrical safety of mobile (inventory) buildings made of metal or having a metal frame, intended for street trading and consumer services ...

GOST R 50462-2009

Basic principles and security principles for the human-machine interface, execution and identification. Identification of conductors by means of colors and alphanumeric designations.
Federal Agency for Technical Regulation and Metrology of the Russian Federation

General rules to use certain colors and alphanumeric designations to identify conductors in order to ensure safety in the operation of electrical equipment and electrical installations. The alphanumeric designations of conductors established in this standard are intended for use in cable products, tires, electrical equipment and electrical installations.

Federal Standard No. S24.802 (USA)

GENERAL REQUIREMENTS FOR GROUND ELECTRONIC EQUIPMENT

Federal Standard No. S24.809 (USA)

GROUNDING STANDARD

Establishes standard electrical, electronic, and mechanical requirements for grounding electronic equipment.

IEEE Std 142-1991 (USA)

IEEE Std 142-2007 (USA)
replacement Std 142-1991

Recommended Practice for Grounding of Industrial and Commercial Power Systems
Institute of Electrical and Electronics Engineers (IEEE)

IEEE Std 602-1996 (USA)

Recommended Practice for Electric Systems in Health Care Facilities
Institute of Electrical and Electronics Engineers (IEEE)

IEEE Std 1100-1999 (USA)

Recommended Practice for Powering and Grounding Electronic Equipment
Institute of Electrical and Electronics Engineers (IEEE)

MIL-STD-1542B (USA)

MILITARY STANDARD. ELECTROMAGNETIC COMPATIBILITY AND GROUNDING REQUIREMENTS FOR SPACE SYSTEM FACILITIES
Department of Defense USA

US Department of Defense Standard for EMC and Grounding Requirements for Aerospace System Objects.

FAA-STD-019e (USA)

LIGHTNING AND SURGE PROTECTION GROUNDING BONDING AND SHIELDING REQUIREMENTS FOR FACILITIES AND ELECTRONIC EQUIPMENT
Department of Transportation. Federal Aviation Administration (FAA)

The industry standard for the design of lightning protection devices adopted by the US Department of Air Transport.

GOST R 50571.10-96
(IEC 364-5-54-80)

UDC 696.6:006.354 Group E08

ELECTRICAL INSTALLATIONS OF BUILDINGS
Part 5

SELECTION AND INSTALLATION OF ELECTRICAL EQUIPMENT
Chapter 54

Electrical installations of buildings. Part 5. Selection and erection of electrical equipment. Chapter 54

OKS 27020; 29020
OKSTU 3402

Introduction date 1997-01-01

Foreword

1. PREPARED AND INTRODUCED by the Technical Committee for Standardization TK 337 "Electrical Equipment of Residential and Public Buildings".

3. This standard, with the exception of table 54D, contains the full authentic text of the international standard IEC 364-5-54 (1980) “Electrical installations of buildings. Part 5. Selection and installation of electrical equipment. Chapter 54 Earthing Devices and Protective Conductors” and Amendment No. 1 (July 1982) to this standard.

4. INTRODUCED FOR THE FIRST TIME

5. RE-ISSUE

Introduction

This standard is part of a set of state standards for electrical installations of buildings, developed on the basis of the standards of the International Electrotechnical Commission IEC 364 "Electrical Installations of Buildings".

The requirements of the standard should be taken into account when developing and revising standards, norms and rules for the device, testing, certification and operation of electrical installations.

1 area of use

This standard specifies requirements for earthing devices and protective conductors in electrical installations.

The scope of the standard is according to GOST 30331.1/GOST R 50571.1.

The requirements of this standard are mandatory.

2. Regulatory references

GOST 10434-82. Electrical contact connections. Classification. General technical requirements

GOST 22782.0-81. Explosion-proof electrical equipment. General technical requirements and test methods

GOST 30331.1-95 (IEC 364-1-72, IEC 364-2-70) / GOST R 50571.1-93 (IEC 364-1-72, IEC 364-2-70) Electrical installations of buildings. Key points

GOST 30331.2-95 (IEC 364-3-93) / GOST R 50571.2-94 (IEC 364-3-93) Electrical installations of buildings. Part 3. Key Features

GOST 30331.3-95 (IEC 364-4-41-92) / GOST R 50571.3-94 (IEC 364-4-41-92) Electrical installations of buildings. Part 4. Security requirements. Protection against electric shock.

541. General requirements

541.1. The operational characteristics of the grounding device must meet the safety requirements and ensure the normal operation of the electrical installation.

542. Grounding

542.1. Grounding devices.

542.1.1. Grounding devices can be combined or separate for protective or functional purposes, depending on the requirements of the electrical installation.

542.1.2. Grounding devices must be selected and installed in such a way that:

— the value of the spreading resistance of the grounding device complied with the requirements for ensuring the protection and operation of the installation during the period of operation;

— the flow of earth fault currents and leakage currents does not create a hazard, in particular with regard to heating, thermal and dynamic withstand;

- the necessary strength or additional mechanical protection was provided depending on the specified external factors in accordance with GOST 30331.2 / GOST R 50571.2.

542.1.3. Measures must be taken to prevent damage to metal parts due to electrolysis.

542.2. Grounding.

542.2.1. As grounding conductors, those in contact with the ground can be used:

- metal rods or pipes

- metal strips or wire;

- metal plates, plates or sheets;

- foundation ground electrodes;

- steel reinforcement of reinforced concrete;

Note. The possibility of using prestressed reinforcement in reinforced concrete as grounding conductors must be justified by calculation data;

- steel water pipes in the ground, subject to the conditions of 542.2.5;

— other underground structures meeting the requirements of 542.2.6.

542.2.3. The material and design of earth electrodes must be resistant to corrosion.

542.2.4. When designing grounding devices, one should take into account the possible increase in their spreading resistance due to corrosion.

Note. It is desirable that the reliability of grounding devices does not depend on other systems.

Note. This requirement does not preclude their inclusion in the potential equalization system in accordance with GOST 30331.3 / GOST R 50571.3.

542.3. Grounding conductors.

542.3.1. Grounding conductors must meet the requirements of 543.1 and, if they are laid in the ground, their cross section must correspond to the values \u200b\u200bspecified in Table. 54A.

Table 54A - Smallest dimensions of earthing conductors laid in the ground

542.4. Main earth clamps or bars.

542.4.1. Each installation shall have a main earthing clamp or bar and to it (or to it) shall be connected:

- grounding conductors;

- protective conductors;

- conductors of the main potential equalization system (see Appendix B);

- conductors of working grounding (if required).

543. Protective conductors

Note. For requirements for protective conductors for potential equalization systems, see section 547.

543.1. The smallest cross-sectional areas of protective conductors shall be:

— calculated in accordance with 543.1.1 or

— selected in accordance with 543.1.2.

In both cases, the requirements of 543.1.3 should be taken into account.

Note. The earthing terminal of the installation equipment must allow the connection of protective conductors.

543.1.1. The cross-sectional area of the protective conductor S, mm 2, must not be less than the value determined by the following formula (applies only for a trip time of not more than 5 s):

where I is the effective value of the short-circuit current flowing through the protection device with a negligible transient resistance, A;

t is the time delay of the disconnecting device, s;

Note. The current limiting by the circuit resistance and the limiting capacity (Joule integral) of the protection device must be taken into account.

k is a coefficient whose value depends on the material of the protective conductor, its insulation and the initial and final temperatures. (The formula for calculation is given in Appendix A). The value of k for protective conductors under various conditions is given in Tables 54B to 54E.

If the formula results in a non-standard cross-section, conductors of the nearest larger standard cross-section should be used.

Note.

1. It is necessary that the section calculated in this way correspond to the conditions determined by the resistance of the "phase - zero" circuit.

2. The value of the maximum temperature for electrical installations in hazardous areas is set according to GOST 22782.0.

3. Observe the maximum permissible clamp temperatures.

Table 54B - Values of the factor k for insulated protective conductors not included in the cable and for bare conductors touching the sheath of cables

Note. The initial temperature of the conductor is assumed to be 30°C.

Table 54C - Value of the k-factor for a protective conductor included in a stranded cable

Table 54D - Value of the k-factor when using cable sheath or armor as a protective conductor

* k-values for conductors made of aluminium, lead or steel, which are not specified in IEC 364-5-54-80.

Table 54E - Factor value for bare conductors for conditions where specified temperatures do not pose a risk of damage to nearby materials

* The indicated temperatures are only permitted if they do not impair the quality of the joints.

Note. The initial temperature of the conductor is assumed to be 30°C.

543.1.2. The cross section of protective conductors must not be less than the values given in table 54F. In this case, it is not necessary to check the section for compliance with 543.1.1.

Table 54F In millimeters squared

Section of phase conductors	The smallest cross section of protective conductors
S ≤ 16 16 S > 35	S 16 S/2

2.5 mm 2 - in the presence of mechanical protection;

4 mm 2 - in the absence of mechanical protection.

Note. When selecting and laying protective conductors, external influencing factors should be taken into account in accordance with GOST 30331.2 / GOST R 50571.2.

543.2. Types of protective conductors.

543.2.1. The following can be used as protective conductors:

- conductors of multicore cables;

- insulated or uninsulated wires in a common sheath with phase wires;

- permanently laid uninsulated or insulated conductors

— metallic sheaths of cables, e.g. aluminum cable sheaths, screens, some cable armor

- metal pipes or metal sheaths for conductors;

- some conductive elements that are not part of the electrical installation (third-party conductive parts), for example, metal building structures of buildings and industrial structures (crane tracks, galleries, elevator shafts, etc.).

a) the electrical continuity of the circuit is carried out in such a way that it is protected from mechanical, chemical and electrochemical damage;

543.1