Grounding devices

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Encyclopedia of radio electronics and electrical engineering / Electrician

Section 2. Electrical equipment and electrical installations for general purposes

Chapter 2.7. Grounding devices

Free technical library

Encyclopedia of radio electronics and electrical engineering / Rules for the technical operation of consumer electrical installations (PTE)

Comments on the article

2.7.1. This chapter applies to all types of grounding devices, potential equalization systems, etc. (hereinafter - grounding devices).

2.7.2. Grounding devices must comply with the requirements of state standards, electrical installation regulations, building codes and regulations and other regulatory and technical documents, ensure the safety of people, operating modes and protection of electrical installations.

2.7.3. The admission to operation of grounding devices is carried out in accordance with the established requirements.

When commissioning a grounding device, the installation organization must submit documentation in accordance with the established requirements and rules.

2.7.4. The connection of grounding conductors to the ground electrode system and grounding structures must be carried out by welding, and to the main grounding clamp, bodies of apparatuses, machines and supports of overhead lines - by bolting (to enable measurements). Contact connections must meet the requirements of state standards.

2.7.5. Installation of grounding conductors, grounding conductors, connection of grounding conductors to grounding conductors and equipment must comply with the established requirements.

2.7.6. Each part of the electrical installation to be grounded or grounded must be connected to the grounding or grounding network using a separate conductor. Serial connection by grounding (zeroing) conductors of several elements of the electrical installation is not allowed.

The cross section of grounding and zero protective conductors must comply with the rules for electrical installations.

2.7.7. Exposed ground conductors must be protected from corrosion and painted black.

2.7.8. To determine the technical condition of the grounding device, visual inspections of the visible part, inspections of the grounding device with selective opening of the soil, measurement of the parameters of the grounding device in accordance with the standards for testing electrical equipment (Appendix 3) should be carried out.

2.7.9. Visual inspections of the visible part of the grounding device must be carried out according to the schedule, but at least once every 1 months by the Consumer's electrical equipment or an employee authorized by him.

During the inspection, the condition of the contact connections between the protective conductor and the equipment, the presence of an anti-corrosion coating, and the absence of breaks are assessed.

The results of inspections should be recorded in the passport of the grounding device.

2.7.10. Inspections with selective opening of the soil in places most susceptible to corrosion, as well as near the grounding points of neutrals of power transformers, connections of arresters and surge arresters should be carried out in accordance with the schedule of scheduled preventive maintenance (hereinafter referred to as PPR), but at least once every 12 years . The size of the section of the grounding device subjected to selective opening of the soil (except for overhead lines in populated areas - see clause 2.7.11) is determined by the decision of the technical manager of the Consumer.

2.7.11. Selective opening of the soil is carried out on all grounding devices of the Consumer's electrical installations; for overhead lines in populated areas, opening is carried out selectively at 2% of supports with grounding devices.

2.7.12. In areas with high soil aggressiveness, by decision of the technical manager of the Consumer, a more frequent inspection frequency with selective opening of the soil can be established.

When opening the soil, an instrumental assessment of the condition of the grounding conductors and an assessment of the degree of corrosion of the contact joints should be carried out. The ground electrode element must be replaced if more than 50% of its section is destroyed.

The results of inspections must be documented.

2.7.13. To determine the technical condition of the grounding device in accordance with the standards for testing electrical equipment (Appendix 3), the following must be carried out:

type="disc">

measuring the resistance of the grounding device;

touch voltage measurement (in electrical installations, the grounding device of which is made according to the standards for touch voltage), checking the presence of a circuit between the grounding device and the grounded elements, as well as the connections of natural grounding conductors with the grounding device;

measurement of short-circuit currents of an electrical installation, checking the condition of breakdown fuses;

measurement of soil resistivity in the area of the grounding device.

For overhead lines, measurements are made annually at poles with disconnectors, protective gaps, arresters, re-grounding of the neutral wire, and also selectively at 2% of reinforced concrete and metal poles in populated areas.

Measurements should be carried out during the period of the greatest drying of the soil (for permafrost areas - during the period of the greatest freezing of the soil).

The measurement results are documented in protocols.

At the main step-down substations and transformer substations, where it is impossible to disconnect the grounding conductors from the equipment due to the conditions for ensuring the categorization of the power supply, the technical condition of the grounding device should be assessed based on the measurement results and in accordance with clauses 2.7.9 - 11.

2.7.14. Measurements of the parameters of the grounding devices - the resistance of the grounding device, the contact voltage, checking the presence of a circuit between the ground electrodes and the grounded elements - are also made after the reconstruction and repair of the grounding devices, upon detection of destruction or overlapping of the overhead line insulators by an electric arc.

If necessary, measures should be taken to bring the parameters of grounding devices to the normative ones.

2.7.15. Each grounding device in operation must have a passport containing:

type="disc">

executive scheme of the device with references to capital structures;

the connection with above-ground and underground communications and with other grounding devices is indicated;

date of commissioning;

main parameters of ground electrodes (material, profile, linear dimensions);

the value of the resistance to the spreading of the current of the grounding device;

soil resistivity;

contact voltage data (if necessary);

data on the degree of corrosion of artificial ground electrodes;

data on the resistance of the metal connection of equipment with a grounding device;

a list of inspections and identified defects;

information on elimination of remarks and defects.

The passport must be accompanied by the results of visual inspections, ground penetration inspections, protocols for measuring the parameters of the grounding device, data on the nature of repairs and changes made to the design of the device.

2.7.16. To check the compliance of the melting currents of the fuses or the settings of the releases of the circuit breakers with the short-circuit current in electrical installations, a check of the operation of the protection in the event of a short circuit should be periodically carried out.

2.7.17. After each rearrangement of electrical equipment and installation of a new one (in electrical installations up to 1000 V), before turning it on, it is necessary to check the operation of the protection in case of a short circuit.

2.7.18. The use of earth as a phase or neutral wire in electrical installations up to 1000 V is not allowed.

2.7.19. When using residual current devices (hereinafter - RCD) in an electrical installation, it must be checked in accordance with the manufacturer's recommendations and electrical equipment test standards (Appendix 3).

2.7.20. Networks up to 1000 V with isolated neutral must be protected by a blowout fuse. The fuse can be installed in the neutral or phase on the low voltage side of the transformer. In this case, control over its integrity should be provided.

See other articles Section Rules for the technical operation of consumer electrical installations (PTE).

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

A New Way to Control and Manipulate Optical Signals 05.05.2024

The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>

Primium Seneca keyboard 05.05.2024

Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Random news from the Archive

3D printing of metal objects at room temperature 14.07.2023

Scientists from the University of North Carolina have developed a unique compound that allows metal products to be printed using a 3D printer at normal room temperature. This significant breakthrough opens up new possibilities for creating metal objects, including those that are sensitive to high temperatures, such as in the field of electronics.

The basis of the new material is an aqueous suspension of copper microparticles. Microparticles of the eutectic alloy of gallium with indium (EGaIn) and hydrochloric acid are added to it. The latter changes the pH of the water to a value of 1,0, which removes oxides from EGaIn and temporarily turns it into a liquid metal state. EGaIn globules attach to larger copper particles, forming strong bonds between them. To increase the volume of the mixture, methylcellulose is added to it.

The resulting viscous gel can be extruded from the nozzle of a conventional 3D printer at room temperature, allowing objects to be created by layering in succession. After printing, the object dries at the same temperature, causing the water and hydrochloric acid to evaporate. Thus, a solid three-dimensional object with high electrical conductivity is obtained, consisting of 97,5% metal (the remaining 2,5% is methylcellulose).

By controlling the extrusion of the gel and applying heat to dry quickly, the object can be shaped into the desired shape: an initially flat blank can be transformed into a complex part. In one example of using this technology, a spider was created that rose to its feet as it dries out when heated. This demonstrates the potential of the new method to print metal objects with high precision and flexibility at normal temperatures.

Other interesting news:

▪ Retinal scanner for smartphone

▪ Electric buses with fast charging

▪ Child with three parents

▪ body music

▪ Surface defrosting in a second

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Regulators of current, voltage, power. Article selection

▪ article Psychoactive substances and mechanisms of drug addiction formation. Basics of safe life

▪ article Where can I listen to the organ played by the waves and the wind? Detailed answer

▪ article Electrician for lighting and lighting networks. Standard instruction on labor protection

▪ article Light controls the model. Encyclopedia of radio electronics and electrical engineering

▪ article Powerful voltage stabilizer for a wind generator. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews