GOST 50571.21-2000 (IEC 60364-5-548-96) UDC 696.6:006.354 Group E08 STATE STANDARD OF THE RUSSIAN FEDERATION Electrical installations of buildings Part 5: SELECTION AND INSTALLATION OF ELECTRICAL EQUIPMENT Section 548 Earthing system and equalizing electrical potentials in electrical installations containing information processing equipment Electrical installations of buildings. Part 5. Selection and erection of electrical equipment. Section 548. Earthing arrangements and equipotential bonding for information technology installations OKS OKS 3402 91.140.50 29.120.50 Effective date 1/1/2002 Preface 1 to develop the All-Russian Research Institute for Electrification of Agriculture (VIESKh) and the All-Russian Research Institute of Standardization and Certification in Engineering (VNIINMASH), introduced by the Technical Committee for Standardization TC 337 "Electrical installations of residential and public buildings" 2 adopted and put into operation the Decree of the State Standard of Russia on Dec. 18, 2000 № 375-Article 3 of this standard is the authentic text of the international standard IEC 60364-5 - 548-96, "Electrical installations of buildings. Part 5. Selection and installation of electrical equipment. Section 548. System grounding and bonding of electrical systems and information technology equipment with additional requirements taking into account the needs of the country's economy was first introduced 4 Type This standard is part of the 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." It represents the authentic text of the international standard IEC 60364-5-548-96, except section 1 (548.1.1), the qualifying features of this standard in the National Energy Section 2 (548.1.2), supplementing the relevant paragraph 548.1.2 IEC 60364 -5-548-96, and section 3 (548.1.3), which eliminates ambiguity in the interpretation of terms and requirements (in italics) to reflect the needs of different sectors of the economy, including agricultural production. In this standard, the requirements to technical resources, aimed at eliminating or limiting to an acceptable level of surge that may cause undesired operation of information technology equipment, as well as any other electronic equipment, sensitive to disturbance, such as medical, laboratory, etc. These tools include the grounding device, including the grounding of electrically independent, device adjustment and leveling of electric potentials. The numbering of chapters, paragraphs and subparagraphs of this standard, starting with 548.2, and drawings are in conformity with IEC 60364-5-548-96. Requirements of the standard complement, modify or supersede the requirements of other private standards set state standards for electrical installations of buildings. The absence of references to the chapter, section or paragraph of the private standard means that the relevant requirements of the standard apply to this case. 1 (548.1.1) Scope This standard applies to electrical installations of buildings used in all sectors of the economy, regardless of their affiliation and ownership, and establishes requirements for the selection and installation of electrical equipment, in particular to the choice of construction and installation of grounding devices and systems adjustment and alignment of the electric potentials in electrical installations, containing information processing equipment interconnected to exchange data, as well as other electrical equipment that is sensitive to interference. It is intended to design, installation, commissioning and maintenance organizations of all forms of property are developed, assembled, tested and operated in the above-mentioned electrical grounding devices, including electrically independent grounding, the device adjustment and leveling of electric potentials (UVEP), including Local UVEP, security and low voltage requirements, etc., to complement the IEC 60364-5-548-96 and responsive to the needs of the economy, are given in Appendix D and in italics. The requirements of this standard are mandatory. Notes 1 The information processing equipment includes all types of electrical and electronic business equipment and telecommunications equipment to GOST 50377. Examples of equipment and facilities covered by this standard: - telecommunications equipment and transmission equipment and data processing or installation, using the transmission of signals with the opposite grounded in internal and external connections to the building - electrical DC network serving the information processing equipment inside the building - installation or equipment to PBXs with incoming and outgoing calls - local computer networks - the alarm system within the premises, acting on the touch, and fire alarm systems - installation services, such as direct digital control system - the system of industrial design and other activities on the basis of computers. 2 In this standard the term "functional" refers to the use of grounding systems and equalizing electrical potentials for electromagnetic compatibility (EMC), information equipment, as well as for the purpose of transmitting signals without distortion, which in the absence of such a conductor can cause interference (see 548.1.3 ). 3 If the protection of electrical installations from lightning and switching surges and overvoltage caused by electromagnetic effects, should be guided by the requirements set forth in the GOST R 50571.19 and GOST R 50571.20. 4 In the case of EMC problems related to the current (existing) building electrical installation, you must use the information contained in Appendix A to this standard. 5 Requirements of this standard does not apply to equipment with high leakage currents (differential currents). With respect to such equipment should comply with 707.1, 707.4 GOST R 50571.22. 2 (548.1.2) Statutory references in this standard references to the following standards: GOST 30326-95 (IEC 950-86) / GOST R 50377-92 (IEC 950-86) Safety of information technology equipment, including electrical office equipment GOST 30331.2 -95 (IEC Zb4-3-93) / GOST 50571.2-94 (IEC 364-3-93) Electrical installations of buildings. Part 3. Key features Standard 30331.3-95 (IEC 364-4-41-92) / GOST 50571.3-94 (IEC 364-4-41-92) Electrical installations of buildings. Part 4. Security requirements. Protection against electric shock 30331.4-95 Standard (IEC 364-4-42-80) / GOST 50571.4-94 (IEC 364-4-42-80) Electrical installations of buildings. Part 4. Security requirements. Protection against thermal effects GOST 50571.10-96 (IEC 364-5-54-80) Electrical installations of buildings. Part 5. Selection and installation of electrical equipment. Chapter 54. Earthing and protective conductors GOST 50571.14-96 (IEC 364-7-705-84) Electrical installations of buildings. Part 7. Requirements for special installations. Section 705. Electrical installations of agricultural and livestock premises GOST 50571.19-2000 (IEC 60364-4-443-95) Electrical installations of buildings. Part 4. Security requirements. Chapter 44. Surge protection. Section 443. Protection of electrical installations from lightning and switching surges GOST 50571.20-2000 (IEC 60364-4-444-96) Electrical installations of buildings. Part 4. Security requirements. Chapter 44. Surge protection. Section 444. Protection of electrical surge caused by electromagnetic effects GOST 50571.22-2000 (IEC 60364-7-707-84) Electrical installations of buildings. Part 7. Requirements for special installations. Section 707. Grounding equipment processing GOST 50571.23-2000 (IEC 60364-7-704-89) Electrical installations of buildings. Part 7. Requirements for special installations. Section. 704. Electrical construction sites 3 (548.1.3) The definitions in this standard, the following terms. 3.1 Land (relative, reference): conductive and which is outside the zone of influence of any earthing of the earth's crust, the electric potential is assumed to be zero. 3.2 Local land: Part of the land, which is in contact with the grounding, the electric potential is influenced by current flowing from the earthing may be different from zero. In cases where the difference from zero potential of the land does not matter, instead of the term "local land" use the generic term "ground". 3.3 to 1 kV electrical installation: electrical, rated voltage not exceeding 1 kV. 3.4 above 1 kV electrical installation: electrical, rated voltage is equal to or greater than 1 kV. 3.5 Electric Network with effectively grounded neutral: Three-phase power network above 1 kV, in which the coefficient of earth fault does not exceed 1.4. 3.6 coefficient of earth fault: The ratio of the potential difference in the three-phase mains between phase and earth intact at the point of ground fault or the other of the other two phases to the potential difference between phase and earth at this point to the circuit. 3.7 conductive parts: Part ability to conduct electrical current. 3.8 neutral conductive part (neutral conductor): Part of the electrical installations that can conduct electrical current, the potential for a normal operating condition is equal or close to zero, such as housing the transformer, switchgear cabinet, casing starter wire bonding system, PEN-conductor, etc. Section 3.9 exposed conductive parts: Affordable touch-neutral conductive part. 10.3 sided conductive parts: conductive part that is not part of the installation. 11.3 conductor: Part is designed to conduct electrical current a certain value. 03.12 live parts: Explorer or conductive parts designed to work under stress in normal operating mode of the installation. 3.13 groundfault: Accidental or intentional (for example, when triggered shorting) the emergence of a conducting connection between a live current carrying parts and ground, or not insulated from the conducting part of the land. 3.14 grounding: Intentional electrical connection to a given point of the system or plant, or equipment to the local earth through the grounding device. 3.15 Functional grounding: Grounding, to ensure the normal functioning of the apparatus, the shell is at the request of the developer should not attend even the smallest electric potential (sometimes this requires the existence of a separate electrically independent earthing). 3.16 earthing device: A group of earthing and grounding conductors. 3.17 Earthing: Part of the grounding device, consisting of one or more electrically interconnected grounding electrodes. 3.18 electrically independent earthing (independent earthing): Grounding, located at a distance from other earthing that currents spreading from them have no significant effect on the electrical potential of the independent earthing. 3.19 grounding conductor: The conductor that connects the grounding point of the system or plant, or equipment grounding. 3.20 Functional grounding conductor (FE-conductor): The grounding conductor in electrical up to 1 kV, an employee for functional earthing. 3.21 grounding electrode (earthing electrode): A conductive part which is in electrical contact with the local land, either directly or through an intermediate conductive medium, such as through a layer of concrete or conductive corrosion-resistant coating. 3.22 potentsialovyravnivayuschy electrode: Same as the ground electrode, but used to equalize electrical potential. 3.23 equalizing electrical potential: The electrical connection of conductive parts with each other to achieve their equipotential. 3.24 protective equalizing electrical potentials: Equalizing the electric potentials in order to ensure electrical safety through the elimination of electrical potential difference between all simultaneously accessible exposed conductive parts of the touch of a stationary electrical equipment and third-party conductive parts, including metal parts of the building constructions, achieved a reliable connection of these parts with one another through conductors. 3.25 main earthing bus (the main earth terminal): Bus or clip, which is part of the electrical grounding device of up to 1 kW and is designed for multi-conductor electrical connection to earth. 3.26 grounding system (grounding system): The sum of the substation grounding devices, exposed conductive parts of the consumer and the neutral conductor in electrical systems up to 1 kV. 3.27 Type of ground: The indicator on the ratio of neutral to ground the transformer in the substation and the exposed conductive parts of the consumer and device neutral conductor. Designation of types of earthing systems - according to GOST R 50571.2 30331.2/GOST. Distinguish TN-, TT-and IT-system, the first two of which are grounded at the transformer substation, and the third - in isolation. TN-system on the device neutral conductor, in turn, is divided into TN-S-, TN-C-and TN-CS-system. 3.28 neutral: Intentional electrical connection to a neutral conducting part (neutral conductor) in electrical systems up to 1 kV grounded neutral transformer at the substation. 3.29 neutral conductor (N-conductor): The conductor in electrical systems up to 1 kV, intended for single-phase power and power consumers connected to the grounded transformer at the substation. 3.30 protective conductor (PE-conductor), conductor in electrical systems up to 1 kV, intended for security purposes and linking the exposed conductive parts of the consumer with a grounding device. 3.31 combined zero-worker and the protective conductor (PEN-conductor): The conductor in electrical systems up to 1 kV, which combines the functions of a zero-worker and protective conductors. 3.32 combined protective and functional earthing conductor (PEF-conductor): The conductor in electrical systems up to 1 kV, which combines the functions of protective and functional earthing conductors. 3.33 Electrical safety division chains: Branch circuits from each other by separating the transformer windings which are separated by a core, an additional one or reinforced insulation. 3.34 Extra Low Voltage (CNS): The voltage does not exceed values ??at which it is not dangerous to humans in areas with high-risk, high-risk and in outdoor settings. 3.35 system safe low voltage (system BSNN): The electrical system in electrical installations up to 1 kV, in which the voltage does not exceed the values ??of the CNS: - In normal operation, electrical, and - in the first insulation damage, including earth fault in other circuits. 3.36 The containment system of low voltage (system ZSNN): The electrical system in electrical systems up to 1 kV where the voltage does not exceed the values ??of the CNS: - In normal operation, electrical, and - in the first insulation fault, except for a ground fault in other circuits. 3.37 potentsialouravnivayuschaya main bus (GPSH): Same as the main grounding bus, but the employee for the purpose of equalizing the electrical potential (often one and the same bus can perform both functions simultaneously). 3.38 potentsialovyravnivayuschaya mesh: Several potentsialovyravnivayuschih electrodes incorporated into the net to extend the alignment of electric potentials. 548.2 Requirements for grounding systems and information technology equipment grounding system and equipment of information technology shall provide protection against electric shock in accordance with the requirements of GOST 30331.3/GOST R 50571.3 and GOST R 50571.10 Additional requirements are needed to ensure reliable and safe operation of plant and equipment information technologies, in particular, to ensure that: - protection from electrolytic corrosion - protection from large reverse currents for functional earthing conductors (FE-provodikam) - the same, and on protective conductors (on the PE and FE-conductors) - EMC and installation of information technology equipment by equipotential bonding them into a single system equalizing electrical potentials. 548.3 Use of main earthing bus Note-If the main earthing bus (the main earth terminal) is used for electrical grounding function, in this case, it can be used for grounding of information technology equipment as a point of connection to the earthing system provided that the requirements of 548.2. 548.3.1 ZSNN system when grounded circuit protective systems, low voltage (ZSNN) and exposed conductive parts of Class II and III are grounded on the basis of functional purposes, for communication with the local land, they must be connected to a system of equalizing the electrical potential according to GOST 30331.3 / GOST R 50571.3 (see Figure 1). Note-secure low voltage (BSNN) according to GOST R 50377 30326/GOST ground, and in this case is considered as ZSNN. Functional grounding can be accomplished by the use of protective conductor (PE-conductor) food chain information technology equipment to the grounding system TN-S. Allowed a functional ground conductor (FE-conductor) and the protective conductor (PE-conductor) to combine into one special wire and attach it to the main earthing bus (main earthing terminal). Figure 1 - Block diagram of equalization of electric potentials of open, dangerous and external conductive parts. 548.4 Compatible units of information technologies with PEN-conductors in the building for buildings, which is installed or can be set to a large number of different information processing equipment or other equipment sensitive to noise, it is necessary to monitor the use of individual protective conductors (PE-conductors) and zero main conductors (N-conductors), after the point of supply of food in order to prevent or minimize electromagnetic effects. Referred to the conductors can not be combined as shown in Figure 2a. Otherwise, the load current, and especially the overcurrent that occurs when a single-phase short circuit, will take place not only at the neutral conductor (N-conductor), but also partly protective conductor, which can lead to interference. If the transformer, diesel generator, uninterruptible power supply or other similar device, as part of the electrical installation of the building, have a system of ground-type TN-C and are used mainly to supply information technology equipment, the output should be to move to a system of ground-type TN-S, as shown in Figure 2b. Paragraph 548.4 specially designed for developers of electrical installations intended for office or industrial use. Part 1. Overview. Section 1. Part 1. General specifications GOST 2.702-75 Unified system for design documentation. Rules for making electronic circuits with GOST 2.752-71 Unified system for design documentation. Graphical symbols in diagrams. Robot device GOST 2.755-87 Unified system for design documentation. Graphical symbols in electrical circuits. Device switching and contact connections GOST 2.756-76 * Unified system for design documentation. Graphical symbols in diagrams. Is often perceived electromechanical devices GOST 2.757-81 * Unified system for design documentation. Graphical symbols in diagrams. Elements of the switching field for switching systems GOST 2.758-81 Unified system for design documentation. Graphical symbols in diagrams. Signal Technology GOST 2.762-85 * Unified system for design documentation. Graphical symbols in electrical circuits. Frequencies and frequency bands for transmission systems GOST 2.763-85 * Unified system for design documentation. Graphical symbols in electrical circuits. Device with a pulse-code modulation GOST 2.764-86 Unified system for design documentation. Graphical symbols in electrical circuits. Integrated optoelectronic display elements GOST 2.768-90 Unified system for design documentation. Graphical symbols in diagrams.
GOST 50571.21-2000 (IEC 60364-5-548-96) UDC 696.6:006.354 Group E08 STATE STANDARD OF THE RUSSIAN FEDERATION Electrical installations of buildings Part 5: SELECTION AND INSTALLATION OF ELECTRICAL EQUIPMENT Section 548 Earthing system and equalizing electrical potentials in electrical installations containing information processing equipment Electrical installations of buildings. Part 5. Selection and erection of electrical equipment. Section 548. Earthing arrangements and equipotential bonding for information technology installations OKS OKS 3402 91.140.50 29.120.50 Effective date 1/1/2002 Preface 1 to develop the All-Russian Research Institute for Electrification of Agriculture (VIESKh) and the All-Russian Research Institute of Standardization and Certification in Engineering (VNIINMASH), introduced by the Technical Committee for Standardization TC 337 "Electrical installations of residential and public buildings" 2 adopted and put into operation the Decree of the State Standard of Russia on Dec. 18, 2000 № 375-Article 3 of this standard is the authentic text of the international standard IEC 60364-5 - 548-96, "Electrical installations of buildings. Part 5. Selection and installation of electrical equipment. Section 548. System grounding and bonding of electrical systems and information technology equipment with additional requirements taking into account the needs of the country's economy was first introduced 4 Type This standard is part of the 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." It represents the authentic text of the international standard IEC 60364-5-548-96, except section 1 (548.1.1), the qualifying features of this standard in the National Energy Section 2 (548.1.2), supplementing the relevant paragraph 548.1.2 IEC 60364 -5-548-96, and section 3 (548.1.3), which eliminates ambiguity in the interpretation of terms and requirements (in italics) to reflect the needs of different sectors of the economy, including agricultural production. In this standard, the requirements to technical resources, aimed at eliminating or limiting to an acceptable level of surge that may cause undesired operation of information technology equipment, as well as any other electronic equipment, sensitive to disturbance, such as medical, laboratory, etc. These tools include the grounding device, including the grounding of electrically independent, device adjustment and leveling of electric potentials. The numbering of chapters, paragraphs and subparagraphs of this standard, starting with 548.2, and drawings are in conformity with IEC 60364-5-548-96. Requirements of the standard complement, modify or supersede the requirements of other private standards set state standards for electrical installations of buildings. The absence of references to the chapter, section or paragraph of the private standard means that the relevant requirements of the standard apply to this case. 1 (548.1.1) Scope This standard applies to electrical installations of buildings used in all sectors of the economy, regardless of their affiliation and ownership, and establishes requirements for the selection and installation of electrical equipment, in particular to the choice of construction and installation of grounding devices and systems adjustment and alignment of the electric potentials in electrical installations, containing information processing equipment interconnected to exchange data, as well as other electrical equipment that is sensitive to interference. It is intended to design, installation, commissioning and maintenance organizations of all forms of property are developed, assembled, tested and operated in the above-mentioned electrical grounding devices, including electrically independent grounding, the device adjustment and leveling of electric potentials (UVEP), including Local UVEP, security and low voltage requirements, etc., to complement the IEC 60364-5-548-96 and responsive to the needs of the economy, are given in Appendix D and in italics. The requirements of this standard are mandatory. Notes 1 The information processing equipment includes all types of electrical and electronic business equipment and telecommunications equipment to GOST 50377. Examples of equipment and facilities covered by this standard: - telecommunications equipment and transmission equipment and data processing or installation, using the transmission of signals with the opposite grounded in internal and external connections to the building - electrical DC network serving the information processing equipment inside the building - installation or equipment to PBXs with incoming and outgoing calls - local computer networks - the alarm system within the premises, acting on the touch, and fire alarm systems - installation services, such as direct digital control system - the system of industrial design and other activities on the basis of computers. 2 In this standard the term "functional" refers to the use of grounding systems and equalizing electrical potentials for electromagnetic compatibility (EMC), information equipment, as well as for the purpose of transmitting signals without distortion, which in the absence of such a conductor can cause interference (see 548.1.3 ). 3 If the protection of electrical installations from lightning and switching surges and overvoltage caused by electromagnetic effects, should be guided by the requirements set forth in the GOST R 50571.19 and GOST R 50571.20. 4 In the case of EMC problems related to the current (existing) building electrical installation, you must use the information contained in Appendix A to this standard. 5 Requirements of this standard does not apply to equipment with high leakage currents (differential currents). With respect to such equipment should comply with 707.1, 707.4 GOST R 50571.22. 2 (548.1.2) Statutory references in this standard references to the following standards: GOST 30326-95 (IEC 950-86) / GOST R 50377-92 (IEC 950-86) Safety of information technology equipment, including electrical office equipment GOST 30331.2 -95 (IEC Zb4-3-93) / GOST 50571.2-94 (IEC 364-3-93) Electrical installations of buildings. Part 3. Key features Standard 30331.3-95 (IEC 364-4-41-92) / GOST 50571.3-94 (IEC 364-4-41-92) Electrical installations of buildings. Part 4. Security requirements. Protection against electric shock 30331.4-95 Standard (IEC 364-4-42-80) / GOST 50571.4-94 (IEC 364-4-42-80) Electrical installations of buildings. Part 4. Security requirements. Protection against thermal effects GOST 50571.10-96 (IEC 364-5-54-80) Electrical installations of buildings. Part 5. Selection and installation of electrical equipment. Chapter 54. Earthing and protective conductors GOST 50571.14-96 (IEC 364-7-705-84) Electrical installations of buildings. Part 7. Requirements for special installations. Section 705. Electrical installations of agricultural and livestock premises GOST 50571.19-2000 (IEC 60364-4-443-95) Electrical installations of buildings. Part 4. Security requirements. Chapter 44. Surge protection. Section 443. Protection of electrical installations from lightning and switching surges GOST 50571.20-2000 (IEC 60364-4-444-96) Electrical installations of buildings. Part 4. Security requirements. Chapter 44. Surge protection. Section 444. Protection of electrical surge caused by electromagnetic effects GOST 50571.22-2000 (IEC 60364-7-707-84) Electrical installations of buildings. Part 7. Requirements for special installations. Section 707. Grounding equipment processing GOST 50571.23-2000 (IEC 60364-7-704-89) Electrical installations of buildings. Part 7. Requirements for special installations. Section. 704. Electrical construction sites 3 (548.1.3) The definitions in this standard, the following terms. 3.1 Land (relative, reference): conductive and which is outside the zone of influence of any earthing of the earth's crust, the electric potential is assumed to be zero. 3.2 Local land: Part of the land, which is in contact with the grounding, the electric potential is influenced by current flowing from the earthing may be different from zero. In cases where the difference from zero potential of the land does not matter, instead of the term "local land" use the generic term "ground". 3.3 to 1 kV electrical installation: electrical, rated voltage not exceeding 1 kV. 3.4 above 1 kV electrical installation: electrical, rated voltage is equal to or greater than 1 kV. 3.5 Electric Network with effectively grounded neutral: Three-phase power network above 1 kV, in which the coefficient of earth fault does not exceed 1.4. 3.6 coefficient of earth fault: The ratio of the potential difference in the three-phase mains between phase and earth intact at the point of ground fault or the other of the other two phases to the potential difference between phase and earth at this point to the circuit. 3.7 conductive parts: Part ability to conduct electrical current. 3.8 neutral conductive part (neutral conductor): Part of the electrical installations that can conduct electrical current, the potential for a normal operating condition is equal or close to zero, such as housing the transformer, switchgear cabinet, casing starter wire bonding system, PEN-conductor, etc. Section 3.9 exposed conductive parts: Affordable touch-neutral conductive part. 10.3 sided conductive parts: conductive part that is not part of the installation. 11.3 conductor: Part is designed to conduct electrical current a certain value. 03.12 live parts: Explorer or conductive parts designed to work under stress in normal operating mode of the installation. 3.13 groundfault: Accidental or deliberate (such as triggering shorting) the emergence of a conducting connection between a live current carrying parts and ground, or not insulated from the conducting part of the land. 3.14 grounding: Intentional electrical connection to a given point of the system or plant, or equipment to the local earth through the grounding device. 3.15 Functional grounding: Grounding, to ensure the normal functioning of the apparatus, the shell is at the request of the developer should not attend even the smallest electric potential (sometimes this requires the existence of a separate electrically independent earthing). 3.16 earthing device: A group of earthing and grounding conductors. 3.17 Earthing: Part of the grounding device, consisting of one or more electrically interconnected grounding electrodes. 3.18 electrically independent earthing (independent earthing): Grounding, located at a distance from other earthing that currents spreading from them have no significant effect on the electrical potential of the independent earthing. 3.19 grounding conductor: The conductor that connects the grounding point of the system or plant, or equipment grounding. 3.20 Functional grounding conductor (FE-conductor): The grounding conductor in electrical up to 1 kV, an employee for functional earthing. 3.21 grounding electrode (earthing electrode): A conductive part which is in electrical contact with the local land, either directly or through an intermediate conductive medium, such as through a layer of concrete or conductive corrosion-resistant coating. 3.22 potentsialovyravnivayuschy electrode: Same as the ground electrode, but used to equalize electrical potential. 3.23 equalizing electrical potential: The electrical connection of conductive parts with each other to achieve their equipotential. 3.24 protective equalizing electrical potentials: Equalizing the electric potentials in order to ensure electrical safety through the elimination of electrical potential difference between all simultaneously accessible exposed conductive parts of the touch of a stationary electrical equipment and third-party conductive parts, including metal parts of the building constructions, achieved a reliable connection of these parts with one another through conductors. 3.25 main earthing bus (the main earth terminal): Bus or clip, which is part of the electrical grounding device of up to 1 kW and is designed for multi-conductor electrical connection to earth. 3.26 grounding system (grounding system): The sum of the substation grounding devices, exposed conductive parts of the consumer and the neutral conductor in electrical systems up to 1 kV. 3.27 Type of ground: The indicator on the ratio of neutral to ground the transformer in the substation and the exposed conductive parts of the consumer and device neutral conductor. Designation of types of earthing systems - according to GOST R 50571.2 30331.2/GOST. Distinguish TN-, TT-and IT-system, the first two of which are grounded at the transformer substation, and the third - in isolation. TN-system on the device neutral conductor, in turn, is divided into TN-S-, TN-C-and TN-CS-system. 3.28 neutral: Intentional electrical connection to a neutral conducting part (neutral conductor) in electrical systems up to 1 kV grounded neutral transformer at the substation. 3.29 neutral conductor (N-conductor): The conductor in electrical systems up to 1 kV, intended for single-phase power and power consumers connected to the grounded transformer at the substation. 3.30 protective conductor (PE-conductor), conductor in electrical systems up to 1 kV, intended for security purposes and linking the exposed conductive parts of the consumer with a grounding device. 3.31 combined zero-worker and the protective conductor (PEN-conductor): The conductor in electrical systems up to 1 kV, which combines the functions of a zero-worker and protective conductors. 3.32 combined protective and functional earthing conductor (PEF-conductor): The conductor in electrical systems up to 1 kV, which combines the functions of protective and functional earthing conductors. 3.33 Electrical safety division chains: Branch circuits from each other by separating the transformer windings which are separated by a core, an additional one or reinforced insulation. 3.34 Extra Low Voltage (CNS): The voltage does not exceed values ??at which it is not dangerous to humans in areas with high-risk, high-risk and in outdoor settings. 3.35 system safe low voltage (system BSNN): The electrical system in electrical installations up to 1 kV, in which the voltage does not exceed the values ??of the CNS: - In normal operation, electrical, and - in the first insulation damage, including earth fault in other circuits. 3.36 The containment system of low voltage (system ZSNN): The electrical system in electrical systems up to 1 kV where the voltage does not exceed the values ??of the CNS: - In normal operation, electrical, and - in the first insulation fault, except for a ground fault in other circuits. 3.37 potentsialouravnivayuschaya main bus (GPSH): Same as the main grounding bus, but the employee for the purpose of equalizing the electrical potential (often one and the same bus can perform both functions simultaneously). 3.38 potentsialovyravnivayuschaya mesh: Several potentsialovyravnivayuschih electrodes incorporated into the net to extend the alignment of electric potentials. 548.2 Requirements for grounding systems and information technology equipment grounding system and equipment of information technology shall provide protection against electric shock in accordance with the requirements of GOST 30331.3/GOST R 50571.3 and GOST R 50571.10 Additional requirements are needed to ensure reliable and safe operation of plant and equipment information technologies, in particular, to ensure that: - protection from electrolytic corrosion - protection from large reverse currents for functional earthing conductors (FE-provodikam) - the same, and on protective conductors (on the PE and FE-conductors) - EMC and installation of information technology equipment by equipotential bonding them into a single system equalizing electrical potentials. 548.3 Use of main earthing bus Note-If the main earthing bus (the main earth terminal) is used for electrical grounding function, in this case, it can be used for grounding of information technology equipment as a point of connection to the earthing system provided that the requirements of 548.2. 548.3.1 ZSNN system when grounded circuit protective systems, low voltage (ZSNN) and exposed conductive parts of Class II and III are grounded on the basis of functional purposes, for communication with the local land, they must be connected to a system of equalizing the electrical potential according to GOST 30331.3 / GOST R 50571.3 (see Figure 1). Note-secure low voltage (BSNN) according to GOST R 50377 30326/GOST ground, and in this case is considered as ZSNN. Functional grounding can be accomplished by the use of protective conductor (PE-conductor) food chain information technology equipment to the grounding system TN-S. Allowed a functional ground conductor (FE-conductor) and the protective conductor (PE-conductor) to combine into one special wire and attach it to the main earthing bus (main earthing terminal). Figure 1 - Block diagram of equalization of electric potentials of open, dangerous and external conductive parts. 548.4 Compatible units of information technologies with PEN-conductors in the building for buildings, which is installed or can be set to a large number of different information processing equipment or other equipment sensitive to noise, it is necessary to monitor the use of individual protective conductors (PE-conductors) and zero main conductors (N-conductors), after the point of supply of food in order to prevent or minimize electromagnetic effects. Referred to the conductors can not be combined as shown in Figure 2a. Otherwise, the load current, and especially the overcurrent that occurs when a single-phase short circuit, will take place not only at the neutral conductor (N-conductor), but also partly protective conductor, which can lead to interference. If the transformer, diesel generator, uninterruptible power supply or other similar device, as part of the electrical installation of the building, have a system of ground-type TN-C and are used mainly to supply information technology equipment, the output should be to move to a system of ground-type TN-S, as shown in Figure 2b. Paragraph 548.4 specially designed for developers of electrical installations intended for office or industrial use. In Figure 2a, the current in the neutral conductor (PEN-conductor), caused by unbalanced loads in three-phase, split between the PEN-conductor, external conductive parts, screens, and cable sheathing, as well as agents designed for information exchange, and thus causes the appearance of interference . With the passage of current in the PEN-conductor is the voltage drop DU = DU1 + DU2. In TN-S-system neutral conductor current flows only on the neutral conductor (N-conductor), without causing a voltage drop in PE Explorer. Figure 2a - The grounding system such as TN-C 1) - the path of currents at eliminating the voltage drop along the DU PE, 2) - connecting conductor equalize electrical potential in a limited area. Note - The system TN-S eliminates the current in the neutral conductor, as shown in Figure 2a, and thus eliminates the DU. Figure 2b - Diagram eliminate the currents in the neutral conductor by the use of the building grounding system such as TN-S. 548.5 Protection against electrolytic corrosion in the cases when the functional ground conductor (or conductors working grounding and protection) is a constant current to prevent electrolytic corrosion must comply with the requirements of paragraph 512.2 GOST GOST R 50571.23 and 50571.10 548.6 Conditions for Electromagnetic Compatibility Note-See Appendix In a GOST R 50571.21 and IEC 01.01.1000 [1]. 548.7 Grounding and equalization capabilities in information technology units 548.7.1 main earthing bus building main earthing bus of the building can be extended by connecting to it additional elements made from the same metal the same section as the main grounding bus so that the installation information processing could be connected to the main earthing bus (main earthing terminal), the shortest route from any point of the building. In accordance with 413.1.2.1 30331.3/GOST GOST P 50571.3 any grounding conductor may be connected to the main earthing bus at any point (IEC 1024-1 [2]). Notes 1 The conductor grounding bus shall be available for the connection. It is desirable to establish in the form of a connecting ring conductor (closed loop), passing along the periphery of the inside of the building (along the contour of the building). 2 Effective equipotential bonding (equalizing electrical potential) between two points on the grounding conductor bus depends on the impedance of the used section of the conductor. Impedance of the conductor depends on the choice of the correct size and route of. At 50 or 60 Hz, which is often the case, copper wire section of 50 mm2 was a good compromise between the cost of material and impedance. 548.7.1.1 Choice section of the conductor Conductor main grounding bus shall be selected in the same way as the conductor section of the main equipotential bonding (the main potentsialouravnivayuschey tires) in accordance with the requirements of 547.1.1 GOST R 50571.10. Note-It should be remembered that the section of ground conductor, the required functions of information technology (functional earth FE-conductor) may exceed the requirements of protection against electric shock (protective earth conductor PE). 548.7.1.2 Connections to the grounding conductor bus to the grounding conductor bus may be connected: - all conductors that meet the requirements of 413.1.2.1 30331.3/GOST GOST R 50571.3 and paragraph 542.4.1 GOST R 50571.10 - conducting screens, shells, and book a cover telecommunication cables or telecommunications equipment; - equipotential bonding conductor rail systems; - grounding wires to protect against over-voltage - radio antenna grounding conductor - a conductor grounding system grounded DC power supply for information technology equipment - Functional grounding conductors - the conductors of lightning protection systems ( IEC 1024-1) [2] - additional equipotential bonding conductors in accordance with paragraph 747.1.2 GOST R 50571.10. 548.7.1.3 selection and installation in cases where you must install the grounding bus, which serves to ground a large number of information technology equipment, it must be installed in a building in the form of a closed loop, mounted on the walls of the room. Grounding conductor bus may be "naked" (non-isolated) and unpainted. This conductor (preferably copper) must be installed so that access to it was the entire length of, for example on the surface or in highway. "Naked" conductors must be insulated (painted) at the points of support and on sites that pass through the wall to prevent corrosion. 548.7.2 Plans equipotential bonding for functional purposes, 1) Equipotential bonding (leveling and alignment of electric potentials) may include conductors, braided cables and metal buildings, such as aqueducts, pipelines, heating and hot water, metal boxes and conduit potentsialovyravnivayuschie mesh installed on the floors building. In some cases it may be advisable to use structural steel or steel reinforcement in the earth system. Then the reinforcement bars should be welded together and connected to the grounding conductor bus. If welding is not allowed on construction or other reasons, you can use jigs. 2) The requirements for equipotential bonding for functional purposes (eg, section, shape, length) will depend on the frequency range of information processing systems, the prevalence and characteristics of the electromagnetic environment of stability of the operating frequency of the equipment. Potentsialouravnivayuschego cross section of the conductor sandwiched between two pieces of equipment must meet the requirements of 547.1.2 GOST R 50571.10. Note-For single-phase short circuit on the grounded conductive part of the supercurrent can cause excess current in the conductive signal connections between equipment. If potentsialouravnivayuschie conductors in the system of equalizing electrical potentials satisfy the requirements for protective conductors, they should be identified as protective conductors in accordance with paragraph 514.3.1 GOST R 50571.23. When potentsialovyravnivayuschaya mesh is created for functional reasons in a large system of information technology equipment, operating requirements of paragraph 547.1.2 GOST R 50571.10. 548.7.3 functional ground conductor 548.7.3.1 Conductor When you cross functional ground conductor must take into account the possible fault currents that can occur in the conductors, if the functional ground conductor is used both as a return conductor (N-conductor). It is also necessary to take into account the normal flow of rated current and voltage drop in the conductor, the resulting shock. In cases where no relevant data for the choice of the section, they should contact the manufacturer of equipment. 548.7.3.2 Connecting to a Device Surge Protective earthing conductors connecting the device surge protection to the main earthing should be very short and direct (without corners, creating inductance) in order to maximally reduce both active and induction of resistance (impedance ). 548.7.4 Combined functional ground conductor and protect 548.7.4.1 Understanding functional ground conductor and protection must at least meet the requirements for protective conductor along its entire length (section 543 GOST R 50571.10). In addition to meeting the requirements of the cross-section of protective conductors, the conductor of functional earthing and protection must also meet the requirements of paragraph 548.7.3.1 of the standard. Conductor back to the DC power supply equipment of information technology can also serve as a conduit for functional earthing and protection, provided that in case of breaking the chains on the route of the conductor corresponding to a safe voltage (expected touch voltage) between simultaneously accessible conductive parts do not exceed the limit values ??in accordance with paragraph 413.1 30331.3/GOST GOST P 50571.3 (50 VAC or 120 VDC). If the current DC power supply and signal currents produce a voltage drop in the combined functional ground conductor and protection, which could lead to potential differences in steady state, cross-sectional area of ??the conductor shall be such that the voltage drop was limited to a maximum of 1 V. In calculating the voltage drop should we neglect the influence of parallel paths, ie, the calculation should lead to some margin. Note-The main purpose of the requirements of the last paragraph - to limit corrosion. 548.7.4.2 Types functional ground conductor and the protection of examples of different electrical circuits strip conductors, which can be used as a functional ground conductor and protection are given in paragraph 543.2.1 GOST R 50571.10. 548.7.4.3 requirements for carrying out construction details as a functional ground conductor of information technology equipment and protection of electrical continuity path for current functional ground conductor, and protection should be ensured through: - type of construction - the use of connection methods that prevent the deterioration of electrical conductivity due to mechanical, chemical and electrochemical effects. Note, Rules of the connection methods are welded or crimped connections, connections on the rivets and bolts that are tightened and prevent inadvertent loosening. The specific conductivity of any construction details used as a conduit for functional earthing and protection must meet the requirements of paragraph 548.7.4.1 of the standard. When supposed to remove a piece of equipment, protective connection between the remaining parts of the equipment should not be interrupted for as long as the first will not be de-energized such removable piece of equipment. It is recommended that for racks or rows of 10 m or more conductors, functional earthing and protection on both ends were connected to a local potentsialovyravnivayuschey grid or to the conductor main earthing bus. ANNEX A (informative) Connection of signal circuits in buildings with existing wiring, which include the PEN-conductor, or when there are problems of electromagnetic compatibility (EMC) in signal cables because of inadequate measures to ensure EMC in electrical installation (see 548.1) are encouraged to apply The following methods in order to avoid or minimize the problem: - use the fiber-optic lines for signal circuits - use of local isolation transformer with separate windings for the power of information technology equipment to meet the requirements of GOST R 50571.3 30331.3/GOST, particularly paragraph 413.1.5 for the local IT-systems or the provision of paragraph 413.5 for protection by electrical separation of the network - for cables, so as to minimize the closed areas for joint contours, generated power and signal cables. For more information on additional methods see IEC 1000-1-1 [I]. ANNEX B (informative) Measures to ensure the electromagnetic compatibility of plant or equipment of information technology may be subject to malfunction due to currents and voltages induced in the equipment itself and in the connections between individual pieces of equipment. Causes of interference are the transients in the power supply and transient phenomena in the grounding conductors due to lightning storms or load switching (switching noise), electrostatic discharge, the differential voltage in the elements of earth at a frequency of power supply, magnetic and electromagnetic, including high-frequency fields. Below are the main methods for eliminating electromagnetic interference: - The use of error-correcting information technology equipment based on electrical methods, or by the use of error correction - Electric Department facility or information technology equipment from sources of disturbance - providing equipotential bonding between the equipment for the appropriate frequency range - the use of low impedance voltage reference to minimize the potential differential voltage and to provide screening. There are various methods of grounding and equipotential bonding in order to achieve electromagnetic compatibility. The following are examples of such methods. B.1 Method 1 - Radial connected protective conductors This method uses the connection of protective conductors with conductors of power. Protective conductor on each piece of equipment provides sufficient resistance to electromagnetic disturbances (other than transient phenomena occurring in the network), so that the signal cables between pieces of equipment are exposed to most of the incoming noise. Consequently, the equipment must be highly resistant to work satisfactorily. Interference can be reduced considerably, if you create an isolated electrical circuit that serves only to information technology equipment and office (eg by an isolating transformer) from other electrical circuits, grounding, and external metal systems (pipelines, etc.). In some cases, the star grounding point (eg PE-bus in the appropriate switchboard) radially connected conductors functional earthing and protection for information technology equipment may be grounded individual insulated conductors connected to the terminal of the main ground bus (see 548.2). ITD - Information Technology Equipment Figure B.1 - Radial connected protective conductors B.2 Using a local alignment of the electric potentials (potentsialovyravnivayuschey mesh) Effects of conventional protective conductors (PE-conductor) can be re-amplified using a local alignment of electric potential, made in the form potentsialovyravnivayuschey grid , mounted into the concrete floor space in the placement of information technology equipment (see Figure B.2). The degree of alignment of the electric potentials depends on the size of the grid cell - the smaller the cell, the better the potential equalization. Figure B.2 - The local unit alignment of electric potentials as in the case of method 1, the additional stability of the interference can be achieved by isolating the whole supply chain for information technology equipment, including the ground system and potentsialovyravnivayuschuyu grid from other circuits and electrical earthing systems, as well as from external conductive parts such as metalwork. B.3 The system of horizontal and vertical equipotential grounding effect on PE-conductors may be many times enhanced by the use of horizontal and vertical (between floors) equipotential ground through the use of multi-tiered system of equalizing the electrical potential. This system has numerous connections with the construction and technological metal, exposed conductive parts of electrical and metal other purposes (see Figure B.3). Part 1. Overview. Section 1. Part 1. General specifications GOST 2.702-75 Unified system for design documentation. Rules for making electronic circuits with GOST 2.752-71 Unified system for design documentation. Graphical symbols in diagrams. Robot device GOST 2.755-87 Unified system for design documentation. Graphical symbols in electrical circuits. Device switching and contact connections GOST 2.756-76 * Unified system for design documentation. Graphical symbols in diagrams. Is often perceived electromechanical devices GOST 2.757-81 * Unified system for design documentation. Graphical symbols in diagrams. Elements of the switching field for switching systems GOST 2.758-81 Unified system for design documentation. Graphical symbols in diagrams. Signal Technology GOST 2.762-85 * Unified system for design documentation. Graphical symbols in electrical circuits. Frequencies and frequency bands for transmission systems GOST 2.763-85 * Unified system for design documentation. Graphical symbols in electrical circuits. Device with a pulse-code modulation GOST 2.764-86 Unified system for design documentation. Graphical symbols in electrical circuits. Integrated optoelectronic display elements GOST 2.768-90 Unified system for design documentation. Graphical symbols in diagrams.
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