Sunday, October 23, 2011

GOST R IEC 61140-2000 protection against electric shock. General provisions for the security afforded by electrical equipment and installations in their relationship

GOST 50571.9-94 (IEC 364-4-473-77) UDC 696.6:006.354 Group E08 STATE STANDARD OF THE RUSSIAN FEDERATION Electrical installations of buildings Part 4 Protection for safety. APPLICATION OF MEASURES overcurrent protection Electrical instaliations of buildings. Part 4. Protection for safety. Measures of protection against overcurrents OKS 3402 Effective date 1/7/1995 Preface 1 prepared and submitted to the Technical Committee for Standardization TC 337 Electrical equipment of residential and public buildings 2 approved and put into effect by Decision of State Standard of Russia from 29.11.94 № 296 3 This standard contains authentic text of the international standard IEC 364-4-473 (1977) "Electrical installations of buildings. Part 4 Protection for safety. Section 473. Measure of protection against overcurrent 4 Enter FEATURE INTRODUCTION This standard is part of the national standards developed by standards-based International Electrotechnical Commission IEC 364 "Electrical installations of buildings." On the content of the established requirements of this standard is a fundamental part in the application of measures of overcurrent protection in electrical systems of buildings, the provisions which should be guided in all areas falling within the scope of the standardization and certification of electrical installations of buildings in the development or revision of standards, rules and regulations on the device test and maintenance of electrical installations. Numbering sections and paragraphs in the standard are in conformity with IEC standards 364. The numbering system established in the standards IEC 364, provides an indication of numbers of parts and chapters of the international standard IEC designation numbers of sections and paragraphs of private standards. For example, in the notation of paragraph 473.1 of the standard figure 4 represents the part number, 47 - chapter number 473 - the section number of the international standard IEC 364-4-473. The use of this numbering system provides vzaimouvyazku requirements of private standards set standards for electrical installations of buildings according to the rules adopted by the IEC Technical Committee 64 "Electrical installations of buildings." The requirements of this standard largely consistent with the requirements of the existing "Regulations for Electrical (RB, Sixth Edition, Chapter 3.1 and 7.1), and approved Glavtehupravleniem Gosenergonadzor USSR Ministry of Energy, however, in addition to RB this standard introduces a requirement to install devices to protect not only in places mains, where the change section of the conductor, but also in places where change material or design guides, or a way to strip wire, if it reduces long-term value of permissible current conductors. 03/01/1916 SEP paragraph is allowed to install protection devices beyond the point of reducing the cross sections of conductors up to 6 m and 30 m in length in remote places that are not consistent with paragraphs 473.1.1.2 and 473.2.2.1 of the standard, whereby the length of this network section shall not exceed 3 meters PUE requirements inconsistent with the requirements of this standard, the revision of SEP should be brought into compliance with this standard. At the present time, pending a review of SEP, to select the mounting devices of protection for the design and construction of electrical installations of buildings permitted to use the requirements of Chapters 3.1 and 7.1, SEP. These assumptions are given in the notes to the items on 473.1.1.2 and 473.2.2.1 of this standard. 1 Scope This Standard specifies requirements for the application of measures of protection against overcurrent in the operation of electrical installations of buildings. Scope of Standard - GOST R 50571.1. 2 Normative references in this standard references to the following standards: GOST 50571.1-93 Electrical installations of buildings. Key provisions of GOST 50571.3-94 Electrical installations of buildings. Part 4. Security requirements. Protection against electric shock, GOST 50571.5-94 Electrical installations of buildings. Part 4. Security requirements. Overcurrent protection 473 MEASURES overcurrent protection requirements in this section does not take into account the conditions of application of measures of protection against overcurrent, depending on external influences. 473.1 Protection against overcurrent 473.1.1 Placement of devices for protection from overcurrent 473.1.1.1 protection devices should be installed in places of power grid, where the change in cross section, material and design of the conductors or of their method strip causes a decrease in the values ??of long-term allowable current conductors, except listed in 473.1.1.2 and 473.1.2 of this standard. 473.1.1.2 is allowed to install protective devices for point reduction section of the conductor (or changing materials, or the way pads) to the place of consumption, if the wiring between this point and a protective device does not have branches, including outlets and corresponds one of the following conditions: a) the section of wiring is being protected from short circuit currents in accordance with the requirements of Section 434 of GOST R 50571.5, and b) the section of wiring less than 3 m, with the electrical wiring is not located near combustible materials (473.2.2.1) and the risk of short- closure on this site is missing. Note - is allowed to increase the length of the site in accordance with the 03.01.1916 "Regulations for Electrical. 473.1.2 allowed not to install protection devices: a) at sites of wiring where the section changes, or the conductor material and method of installation, if this site is effectively protected against overload protection device, installed in front of this section, and b) on sections of wiring, for which no current can flow overload, provided that the wiring is protected from short circuits in accordance with Section 434 of GOST R 50571.5, c) in the networks of telecommunications, control, signaling, and the like. Requirements of 473.1.2 shall not apply to electrical installations in explosion and fire risk and in cases where safety reasons for some of the rooms are installed with other requirements. 473.1.3 Placement of protective devices in power distribution systems IT Requirements for installation location, or concerning the refusal of protection devices that are listed in 473.1.1.2 and 473.1.2 do not apply to an IT system in cases where each chain, which has no protection against overcurrent , equipped with light-off, which is responsive to the differential residual current, or if all the electrical equipment powered by this circuit, including wiring, made in compliance with protective measures 413.2 GOST 50571.3. 473.1.4. Cases in which it is recommended for security reasons not to install the protective device is recommended not to install protective devices in circuits supplying power to electrical equipment, disconnection which can lead to security threats, such as excitation circuit of electrical machines, power supply circuit lifting electromagnets, the secondary circuit of current transformers. In such cases, should include alarm devices in case of overload. 473.2 Protection against short circuits, 473.2.1 Placement of devices for protection from short circuit protection devices should be installed in places of power grid, where reduced cross-section or other changes that are listed in 473.1.1.1, lead to changes in the values ??of their long-term allowable currents, except listed in 473.2.2 and 473.2.3 of this standard. 473.2.2 allowed to place the device against short circuits in other places other than the requirements of 473.2.1, subject to conditions 473.2.2.1 and 473.2.2.2. 473.2.2.1 Site wiring between the point of reducing the cross section of conductors, or other changes and the point of placing the protection device at the same time satisfies the following conditions: a) the length of the wiring does not exceed 3 m. Note - is allowed to increase the length of the site in accordance with the 01.03.1916 "Regulations for Electrical Installation" b) the wiring is designed so that the risk of short circuit is minimized, for example by protecting it from external influences, and c) electric system is not located near combustible material. 473.2.2.2 protection device, installed in front of the site of electrical conductors with reduced cross-section or other changes, has the performance, that is able to defend against short-circuit wiring harness, located at this site in accordance with the requirements of 434.3.2 GOST 50571.5. 473.2.3 Instances that are not allowed to install the device against short-circuit protection devices are not allowed to set for: - chains connecting the generators, transformers, rectifiers, batteries with the relevant control panels are installed protection devices - chains, off of which may cause electrical hazards in the work, such as described in 473.1.4 - some chains measure - when both of the following two conditions: a) constructive execution site wiring is such that the likelihood of a short circuit is minimal (see 473.2. 2.1b), and b) part of the wiring is not located near any combustible materials. 473.2.4 Protection against short circuits, parallel conductors one and the same protection device can be used to protect several parallel conductors, provided that the performance of protection devices consistent with the method of laying parallel connected conductors. 473.3 Protection requirements depending on the purpose of protection circuits 473.3.1 phase conductors 473.3.1.1. Overcurrent detection should be provided for all phase conductors and cause disabling those for which the supercurrent flows without disabling other conductors, except as provided in 473.3.1.2 of this standard. 473.3.1.2 In TT systems for chains included in the line voltage, in which there is no neutral conductor, the detection of short-circuit current in each conductor is not required if both the following conditions: a) in the same chain on the supply side there is a differential protection intended to provide off-phase conductors, and b) circuit for power consumers, protected by differential protection devices specified in subparagraph a) does not contain the zero main conductor extending from the artificial neutral. Note - If you disconnect one phase can cause dangerous consequences, such as in the case of three-phase motors shall be provided for appropriate action. 473.3.2 Protection of zero Desktop Explorer 473.3.2.1 Systems TT and TN-a) In cases where the zero-section of the working conductor at least equal to or equivalent to cross-phase conductors are not required to provide detection devices short-circuit current in the conductor or the device it off. b) In cases where the zero-section of the working conductor, less cross-phase conductors must be provided for detecting short-circuit current in the neutral conductor corresponding to its cross section, with an impact on off-phase conductors. At the same time working off the zero conductor is required. However, do not need to detect short-circuit current in the neutral conductor, if both of the following conditions: - the neutral conductor is protected against short circuits with protective device of phase conductors of the circuit - the maximum expected current that can flow through the neutral conductor in the normal mode significantly less than the long-term allowable current of the conductor. Note - The second condition is satisfied if the transmitted power as possible evenly distributed between the different phases, for example, if the amount of power for power consumers are connected between each phase and neutral conductor (lights, sockets), much less than the total power transmitted by the chain under consideration. Zero-section of the working conductor must be at least 50% of the cross phase conductor. 473.3.2.2 System IT Systems IT, as a rule, should not have zero working conductor. However, in cases where an IT system with neutral conductor is necessary to provide overcurrent detection devices in the neutral conductor of each circuit with exposure to disconnect all conductors of the respective chain under tension, including the neutral conductor. Do not want to impose such measures if: - the neutral conductor is protected against short circuits by a device installed on the supply side, such as entering into the unit, in accordance with the rules set forth in 434.3 GOST 50571.5 - considered the chain is protected with a device breaker that responds to the differential residual current with the current setting no more than 0.15 maximum current zero working conductor. This device shall disconnect all current-carrying conductors corresponding circuit, including the neutral conductor. If you want to disable the zero main conductor, it must be switched off after shutdown phase conductors and operated simultaneously with the phase conductors or earlier. Key words: electrical buildings; security; protection against overcurrent, placing protection devices, short-circuit protection, protection of phase conductors, the protection of neutral main conductor Published 06/26/2008 GOST on "Electrical, lighting, security systems," GOST 15597-82 Fixtures for industrial buildings. 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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