Detail of GB/T 3906-2020

Introduction of GB/T 3906-2020

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 3906-2006 Alternating-current metal-enclosed switchgear and controlgear for rated voltages above 3.6kV and up to and including 40.5kV. The following main technical changes have been made with respect to GB/T 3906-2006: ——Terms such as solid-insulation embedded component are added (see Clause 3); ——Ratings of the internal arc classification (IAC) are added, and rated arc fault currents and rated arc fault duration are specified (see 5.101); ——Rated cable test voltages are added, and both a.c. and d.c. test voltages are specified (see 5.102); ——Requirements for use of solid-insulation embedded component in the main circuit of switchgear and controlgear are added (see 6.4); ——X-radiation emission test is added (see 6.21); ——The requirement that products under normal production shall be subjected to dielectric test once every 8 years is added (see 7.1); ——"For metal-enclosed switchgear and controlgear with compartments insulated by air and solid-insulation embedded component as main components of main circuit, if the conditions of use for condensation and pollution are stricter than the normal conditions of use specified in this standard, tests shall be conducted in accordance with Annex E. The tests for other types of metal-enclosed switchgear and controlgear may be determined by agreement between manufacturer and user" is added (see 7.2.9); ——Test requirements for use of solid-insulation embedded component in the fluid-filled and/or main circuit of switchgear and controlgear are added (see 7.2.10); ——The test voltage value and test duration of cable testing circuit are specified (see 7.2.101); ——Trial operation requirements for doors or covers, shutters, wrong directions, etc. are added; test requirements for manual operation handles are proposed; verification for integrity of sliders or other devices preventing access to the operation interface is required; additional test requirements for motor-driven interlock are proposed, and criteria are proposed for all of the above tests (see 7.102.2); ——The performance verification test for use of solid-insulation embedded component in the main circuit is added (see 7.107); ——The service continuity of equipment is reclassified into four categories of LSC1/2/2A/2B, with examples available (see 9.102.3); ——The content of 9.103 is adjusted, contents such as IAC classification are added, and Table 3 in GB/T 3906-2006 is adjusted to 9.104; ——Ratings of earthing circuit and cable test are added (see 9.105 and 9.106); ——Influence of the product on the environment is added (see Clause 13); ——“Comparison list of equivalent clause numbering of this standard with IEC 62271-200: 2011” is added (see Annex A); ——Degree of protection against electric shock of solid-insulation enclosed switchgear and controlgear is added (see Annex C); ——Annex E is re-modified according to IEC 62271-304; ——The maximum allowable partial discharge is adjusted; for metal-enclosed switchgear and controlgear filled with fluid and/or with solid-insulation embedded component in main circuit, the maximum allowable partial discharge under the test voltage is determined to be 20pC; for other types of metal-enclosed switchgear and controlgear, the partial discharge measurement test shall meet the requirements that the assembly shall not be greater than 100pC (see F.5). This standard has been redrafted and modified in relation to IEC 62271-200: 2011 High-voltage switchgear and controlgear - Part 200: AC metal-enclosed switchgear and controlgear for rated voltages above 1kV and up to and including 52kV. Many structural adjustments have been made with respect to IEC 62271-200: 2011, and comparison list of equivalent clause numbering of this standard with IEC 62271-200: 2011 is given in Annex A. Technical deviations between this standard and IEC 62271-200: 2011 and their reasons are as follows: ——The adjustments of technical deviations are made for the normative references in this standard so as to adapt to the technical conditions of China. The adjustments are mainly reflected in Clause 2 "Normative references", with the specific adjustments as follows:  IEC 62271-100 is replaced by GB/T 1984-2014 which is modified in relation to the international standard;  IEC 62271-102 is replaced by GB/T 1985-2014 which is modified in relation to the international standard;  IEC 60050-441: 1984 is replaced by GB/T 2900.20-2016 which is modified in relation to the international standard;  IEC 62271-103 is replaced by GB/T 3804 which is modified in relation to the international standard;  IEC 60529: 1989 is replaced by GB/T 4208-2017 which is identical to the international standard;  IEC 60270 is replaced by GB/T 7354 which is identical to the international standard;  IEC 62271-1: 2007 is replaced by GB/T 11022-2011 which is modified in relation to the international standard;  IEC 62271-105 is replaced by GB/T 16926 which is modified in relation to the international standard;  IEC 60060-1 is replaced by GB/T 16927.1-2011 which is modified in relation to the international standard;  ISO/IEC Guide 51: 2014 is replaced by GB/T 20002.4-2015 which is modified in relation to the international standard;  IEC 62262 is replaced by GB/T 20138 which is identical to the international standard;  IEC 60050-151, IEC 60470: 1999, IEC 62271-201: 2006 and IEC/TS 62271-304 are deleted;  GB/T 762, GB/T 1408.1-2016, GB/T 2423.1, GB/T 2423.2, GB/T 2423.22, GB/T 8905-2012 and GB/T 14808-2016 are added; ——"Scope” is modified: “above 1kV and up to and including 52kV” in 1.1 of IEC 62271-200: 2011 is changed to 3.6kV~40.5kV according to the actual power grid situation in China; “service frequencies up to and including 60Hz” in 1.1 of IEC 62271-200: 2011 is changed to “service frequencies up to and including 50Hz” in this standard (see Clause 1); ——Terms such as "solid-insulation embedded component" are added (see Clause 3); ——Requirements for use of solid-insulation embedded component in the main circuit of switchgear and controlgear are added (see 6.4); ——The requirement that products under normal production shall be tested once every 8 years is added (see 7.1); ——"For metal-enclosed switchgear and controlgear with compartments insulated by air and solid-insulation embedded component as main components of main circuit, if the conditions of use for condensation and pollution are stricter than the normal conditions of use specified in this standard, tests shall be conducted in accordance with Annex E. The tests for other types of metal-enclosed switchgear and controlgear may be determined by agreement between manufacturer and user" is added (see 7.2.9); ——Test requirements for use of solid-insulation embedded component in the fluid-filled and/or main circuit of switchgear and controlgear are added (see 7.2.10); ——The performance verification test for use of solid-insulation embedded component in the main circuit is added (see 7.107); ——“Comparison list of equivalent clause numbering of this standard with IEC 62271-200:2011” is added (see Annex A); ——Degree of protection against electric shock of solid-insulation enclosed switchgear and controlgear is added (see Annex C); ——Method for calculating cross-sectional area of bare conductor according to thermal effect of short-term continuous current is added (see Annex D); ——Additional requirements for alternating-current metal-enclosed switchgear and controlgear for rated voltages above 3.6kV and up to and including 40.5kV for severe climatic conditions are added (see Annex E); ——For metal-enclosed switchgear and controlgear filled with fluid and/or with solid-insulation embedded component in main circuit, the maximum allowable partial discharge under the test voltage is determined to be 20pC; for other types of metal-enclosed switchgear and controlgear, the partial discharge measurement test shall meet the requirements that the assembly shall not be greater than 100pC (see F.5); ——“Regional differences” (Annex C) in former standard is deleted. The following editorial changes have been made in this standard: ——In order to be consistent with China's technical standard system, the name of this standard is changed to Alternating-current metal-enclosed switchgear and controlgear for rated voltages above 3.6kV and up to and including 40.5kV; ——Explanatory notes are added (see Annex G). This standard was proposed by China Electrical Equipment Industry Association. This standard is under the jurisdiction of the National Technical Committee on High-voltage Switch Gear of Standardization Administration of China (SAC/TC 65). The previous editions of this standard are as follows: ——GB 3906-1983, GB 3906-1991 and GB/T 3906-2006. Alternating-current metal-enclosed switchgear and controlgear for rated voltages above 3.6kV and up to and including 40.5kV 1 Scope This standard specifies the terms and definitions, service conditions, rating, design and structure, type test, ex-factory test and other technical requirements of 3.6kV~40.5kV AC metal-enclosed switchgear and controlgear. This standard is applicable to prefabricated metal-enclosed switchgear and controlgear for alternating current of rated voltages 3.6kV~40.5kV for indoor and outdoor installation, and for service frequencies up to 50Hz or below. Enclosures may include fixed and removable components and may be filled with fluid (liquid or gas) to provide insulation or disconnection. Note 1: Although primarily dedicated to three-phase systems, this standard may also be applied to single-phase or two-phase systems. This standard defines several categories of metal-enclosed switchgear and controlgear which differ due to ——the consequences on network service continuity in case of maintenance on the switchgear and controlgear; ——the need and convenience of maintenance of the equipment. Note 2: Safety of an installation results from the design, manufacture, use, adjustment, coordination, installations and operations of products. For metal-enclosed switchgear and controlgear containing gas-filled compartments, this standard applies when the design pressure is limited to a maximum of 0.3MPa (relative pressure). Note 3: Gas-filled compartments having a design pressure exceeding 0.3MPa (relative pressure) should be designed and tested in accordance with GB/T 7674. Metal-enclosed switchgear and controlgear for special use, for example, in flammable atmospheres, in mines or on board ships, may be subject to additional requirements. Components contained in metal-enclosed switchgear and controlgear are to be designed and tested in accordance with their various relevant standards. This standard supplements the standards for the individual components regarding their installation in switchgear and controlgear assemblies. This standard does not preclude that other equipment may be included in the same enclosure. In such a case, any possible influence of that equipment on the switchgear and controlgear is to be taken into account. Note 4: Switchgear and controlgear assemblies having an insulation enclosure are covered by IEC 62271-201: 2014. This standard is also applicable to metal-enclosed switchgear and controlgear with rated voltage above 40.5kV, with air-insulation or inflatable compartments and with design pressure not exceeding 0.3MPa (relative pressure). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB 762 Standard current ratings (GB 762-2002, eqv IEC 60059:1999) GB/T 1408.1-2016 Insulating materials - Test methods for electric strength - Part 1: Test at power frequencies (IEC 60243-1:2013, IDT) GB/T 1984-2014 High-voltage alternating-current circuit-breakers (IEC 62271-100:2008, MOD) GB/T 1985-2014 High-voltage alternating-current disconnectors and earthing switches (IEC 62271-102: 2001+A1: 2011, MOD) GB/T 2423.1 Environmental testing - Part 2: Test methods - Tests A: Cold (GB/T 2423.1-2008，IEC 60068-2-1: 2007，IDT) GB/T 2423.2-2008 Environmental testing - Part 2: Test methods - Tests B: Dry heat GB/T 2423.22 Environmental testing - Part 2: Tests methods - Test N: Change of temperature (GB/T 2423.22-2012, IEC 60068-2-14: 2009, IDT) GB/T 2900.20-2016 Electrotechnical terminology - High-voltage switchgear and controlgear (IEC 60050-441:1984, MOD) GB/T 3804 High-voltage alternating current switches for rated voltage above 3.6 kV and less than 40.5 kV (GB/T 3804-2014, IEC 62271-103:2011, MOD) GB/T 4208-2017 Degrees of protection provided by enclosure (IP code) (IEC 60529:2013, IDT) GB/T 7354 Partial discharge measurement (GB/T 7354-2018, IEC 60270: 2000, MOD) GB/T 8905-2012 The guide for management and measuring SF6 gas in electrical equipment (IEC 60480: 2004, MOD) GB/T 11022-2011 Common specifications for high-voltage switchgear and controlgear standards (IEC 62271-1: 2007, MOD) GB/T 14808-2016 High-voltage alternating current contactors, contactor-based controllers and motor starters (IEC 62271-106: 2011, MOD) GB/T 16926 High-voltage alternating current switch-fuse combinations (GB/T 16926-2009, IEC 62271-105: 2002, MOD) GB/T 16927.1-2011 High-voltage test techniques - Part 1:General definitions and test requirements (IEC 60060-1: 2010，MOD) GB/T 20002.4-2015 Drafting for special aspects in standards - Part 4: Safety aspects for their inclusion in standards GB/T 20138 Degrees of protection provided by enclosures for electrical equipment against external mechanical impacts (IK code) (GB/T 20138-2006, IEC 62262: 2002, IDT) 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 2900.20-2016, GB/T 11022-2011 and the followings apply. 3.101 switchgear and controlgear general term covering switching devices and their combination with associated control, measuring, protective and regulating equipment, also assemblies of such devices and equipment with associated interconnections, accessories, enclosures and supporting structures [GB/T 2900.20-2016, Definition 3.1] 3.102 metal-enclosed switchgear and controlgear switchgear and controlgear equipment completely enclosed by earthed metal, except for incoming and outgoing lines [GB/T 2900.20-2016, Definition 4.4] 3.103 functional unit part of metal-enclosed switchgear and controlgear comprising all the components of the main circuits and auxiliary circuits that contribute to the fulfillment of a single function Note 1: Functional units may be distinguished according to the function for which they are intended, for example, incoming unit, outgoing unit, etc. Note 2: GB/T 2900.20-2016 modified, Definition 5.5. 3.104 multi-tier design design of metal-enclosed switchgear and controlgear in which the main switching devices of two or more functional units are arranged vertically (one above the other) within a common enclosure 3.105 transport unit part of metal-enclosed switchgear and controlgear, suitable for shipment without being dismantled 3.106 enclosure part of metal-enclosed switchgear and controlgear providing a specified degree of protection of equipment against external influences and a specified degree of protection against approach to or contact with live parts and against contact with moving parts Note: GB/T 2900.20-2016 modified, Definition 5.1. 3.107 high-voltage compartment compartment of metal-enclosed switchgear and controlgear containing high-voltage conducting parts, enclosed except for openings necessary for interconnection, control or ventilation Note 1: Four types of high-voltage compartments are distinguished, three that can be opened, called accessible (see 3.107.1 to 3.107.3) and one that cannot be opened, called non-accessible (see 3.107.4) Note 2: General definition of "compartment" is provided by 5.6 of GB/T 2900.20-2016, as "a part of an assembly enclosed except for openings necessary for interconnection, control or ventilation". Note 3: A compartment may contain barriers, structures or components that are intended to provide various functions, such as mechanical or dielectrical, but not to function as a partition or enclosure. Note 4: High-voltage compartments may be identified according to the main component(s) contained therein or to the main function provided. 3.107.1 interlock-controlled accessible compartment high-voltage compartment, intended to be opened for normal operation and/or normal maintenance as stated by the manufacturer, in which access is controlled by integral design of the switchgear and controlgear Note: Installation, extension, repair, etc. are not considered as normal maintenance. 3.107.2 procedure-based accessible compartment high-voltage compartment, intended to be opened for normal operation and/or normal maintenance as stated by the manufacturer, in which access is controlled by a suitable procedure combined with locking Note: Installation, extension, repair, etc. are not considered as normal maintenance. 3.107.3 tool-based accessible compartment high-voltage compartment, that may be opened only through the use of tools, but not intended for opening during normal operation and maintenance Note: Special procedures may be required. 3.107.4 non-accessible compartment high-voltage compartment that cannot be opened Note: Opening may destroy the integrity of the compartment. 3.107.5 connection compartment high-voltage compartment in which electrical connections are made between the main circuit of the switchgear assembly and the external conductors (cables or bars) to the electrical network or high-voltage apparatus of the installation Note: For example, cable connection compartment. 3.108 partition part of metal-enclosed switchgear and controlgear separating one high-voltage compartment from other compartments and providing a specified degree of protection Note 1: Movable shutters intended for shielding may become an integral part of the partition. Note 2: Partitions may be fitted with parts that allow interconnection between compartments (e.g. bushings). Note 3: It is revised from GB/T 2900.20-2016, Definition 5.7. 3.109 partition class class defining whether metallic or non-metallic material is used for partitions 3.109.1 partition class PM metal-enclosed switchgear and controlgear providing continuous metallic partitions and/or shutters (if applicable), intended to be earthed, between opened accessible compartments and high-voltage live parts 3.109.2 partition class PI metal-enclosed switchgear and controlgear having one or more non-metallic partitions or shutters between opened accessible compartments and high-voltage live parts 3.110 shutter part of metal-enclosed switchgear and controlgear that may be moved from a position where it permits contacts of a removable part, or moving contact of a disconnector, to engage fixed contacts, to a position where it becomes a part of the enclosure or partition shielding the fixed contacts Note: It is revised from GB/T 2900.20-2016, Definition 5.8. 3.111 segregation (of conductors) arrangement of conductors with earthed metal interposed between them in such a manner that disruptive discharges can only occur to earth Note 1: A segregation may be established between the conductors as well as between the open contacts of a switching device. Note 2: This definition does not specify any mechanical protection (IP and IK). Note 3: It is revised from GB/T 2900.20-2016, Definition 3.11. 3.112 bushing structure carrying one or more conductors through an enclosure or partition and insulating it there from, including the means of attachment 3.113 component essential part of the main circuit or earthing circuits of metal-enclosed switchgear and controlgear which serves a specific function (for example, circuit-breaker, disconnector, earthing switch, load switch, fuse, instrument transformer, bushing, busbar, etc.) 3.114 solid-insulation embedded component independent part of high-voltage conductive component encapsulated with solid insulating materials 3.115 main circuit all the high-voltage conductive parts of metal-enclosed switchgear and controlgear included in a circuit which is intended to carry the rated normal current Note: It is revised from GB/T 2900.20-2016, Definition 5.2. 3.116 earthing circuit conductors, connections, and the conductive parts of earthing devices intended to connect the high-voltage conductive parts to the earthing system of the installation Note: Parts of metallic enclosures connected to the earthing system may be considered as part of the earthing circuit, refer to 6.5. 3.117 auxiliary circuit all the conductive parts of metal-enclosed switchgear and controlgear included in a circuit (other than the high-voltage parts) intended to control, measure, signal and regulate Note: It is revised from GB/T 2900.20-2016, Definition 5.4. 3.118 pressure relief device device intended to relieve over pressure from a compartment 3.119 fluid-filled compartment high-voltage compartment of metal-enclosed switchgear and controlgear filled with a fluid, either gas, other than ambient air, or liquid, for insulation/disconnection purposes 3.119.1 gas-filled compartment compartment of switchgear or controlgear, the gas pressure inside which is maintained by one of the following systems: a) controlled pressure system; b) closed pressure system; c) sealed pressure system Note: Several gas-filled compartments may be permanently connected into a common gas system (gas tightness assembly). [GB/T 11022-2011, Definition 3.6.6.1] 3.119.2 liquid-filled compartment compartment of metal-enclosed switchgear and controlgear in which the liquid is at atmospheric pressure, or under pressure that is maintained by one of the following systems: a) controlled pressure system; b) closed pressure system; c) sealed pressure system Note: For pressure systems, refer to subclause 3.6.5 of GB/T 11022-2011. 3.120 relative pressure pressure, referred to the standard atmospheric pressure of 101.3kPa 3.121 minimum functional level (of fluid-filled compartments) gas pressure (relative pressure) in Pa (or density) or liquid mass Note: At and above this value the ratings of the metal-enclosed switchgear and controlgear are maintained. 3.122 design level (of fluid-filled compartments) gas pressure (relative pressure) in Pa (or density) or liquid mass used to determine the design of a gas-filled compartment or mass for a liquid-filled compartment 3.123 design temperature (of fluid-filled compartments) highest temperature which can be reached by the gas or liquid under service conditions 3.124 ambient air temperature (of metal-enclosed switchgear and controlgear) temperature, determined under prescribed conditions, of the air surrounding the enclosure of metal-enclosed switchgear and controlgear 3.125 removable part part of metal-enclosed switchgear and controlgear connected to the main circuit and that may be removed entirely from the metal-enclosed switchgear and controlgear and replaced, even though the main circuit of the functional unit is live Note: It is revised from GB/T 2900.20-2016, Definition 5.9. 3.126 withdrawable part removable part of metal-enclosed switchgear and controlgear that can be moved to positions in which an isolating distance or segregation between open contacts is established, while the part remains mechanically attached to the enclosure Note: It is revised from GB/T 2900.20-2016, Definition 5.10. 3.127 service position (connected position) position of a removable part in which it is fully connected for its intended function Note: It is revised from GB/T 2900.20-2016, Definition 8.25. 3.128 earthing position position of a removable part or state of a disconnector Note 1: In this state, the closing of a mechanical switching device causes a main circuit to be short-circuited and earthed. Note 2: It is revised from GB/T 2900.20-2016, Definition 8.26. 3.129 test position (of a withdrawable part) position of a withdrawable part in which an isolating distance or segregation is established in the main circuit and in which the auxiliary circuits are connected Note: It is revised from GB/T 2900.20-2016, Definition 8.27. 3.130 disconnected position (of a withdrawable part) position of a withdrawable part in which an isolating distance or segregation is established in the circuits of the withdrawable part, that part remaining mechanically attached to the enclosure Note 1: In high-voltage metal-enclosed switchgear and controlgear, the auxiliary circuits may not be disconnected. Note 2: It is revised from GB/T 2900.20-2016, Definition 8.28. 3.131 removed position (of a removable part) position of a removable part when it is outside and mechanically and electrically separated from the enclosure Note: It is revised from GB/T 2900.20-2016, Definition 8.29. 3.132 loss of service continuity category; LSC category defining the possibility to keep other compartments and/or functional units energized when opening an compartment of main circuit, as stated in definitions 3.107.1 to 3.107.3 Note 1: The LSC category describes the extent to which the switchgear and controlgear are intended to remain operational in case access to a high-voltage compartment is provided. The extent to which it is considered necessary to open high-voltage compartments with a live installation might be dependent on several aspects (refer to 9.102). Note 2: The LSC category does not describe ranks of reliability of switchgear and controlgear (refer to 9.103). Note 3: According to accessible compartments and service continuity, four categories are possible: LSC1, LSC2, LSC2A, LSC2B. 3.132.1 category LSC2 functional unit functional unit with at least one accessible compartment for high-voltage connections (i.e. connection compartments, other than the busbar compartment of single-busbar switchgear) Note 1: When such compartment is open, at least one busbar can remain energized and all other functional units can be operated normally. Note 2: When LSC2 functional units have accessible compartments other than the connection compartment, further subdivisions into LSC2A and LSC2B are defined. 3.132.2 category LSC2A functional unit functional unit of category LSC2 such that, when any accessible compartment (other than the busbar compartment of single-busbar switchgear and controlgear) is open, at least one busbar can remain energized and all other functional units can be operated normally 3.132.3 category LSC2B functional unit functional unit of category LSC2A, where the high-voltage connections (e.g. cable connections) to the functional unit can remain energized when any other accessible high-voltage compartment of the corresponding functional unit is open 3.132.4 category LSC1 functional unit functional unit having one or more high-voltage accessible compartments, such that, when any of these accessible high-voltage compartments is open, at least one other functional unit cannot remain energized 3.133 internal arc classified switchgear and controlgear; IAC metal-enclosed switchgear and controlgear for which prescribed criteria, for protection of persons, are met in the event of internal arc as demonstrated by type tests Note: The internal arc classification is described by the characteristics given from 3.133.1 to 3.133.4. 3.133.1 type of accessibility characteristic related to the level of protection given to people accessing a defined area around the enclosure of switchgear and controlgear 3.133.2 classified sides characteristic related to the accessible sides having a defined level of protection of persons given by the enclosure of the switchgear and controlgear in the event of internal arc 3.133.3 arc fault current three-phase and, where applicable, the single phase-to-earth r.m.s. value of the internal arc fault current for which the switchgear and controlgear is designed to protect persons in the event of an internal arc 3.133.4 arc fault duration duration of the internal arc fault current for which the switchgear and controlgear is designed to protect persons in the event of an internal arc 3.134 degree of protection extent of protection provided by an enclosure, partition or shutter if applicable, against access to hazardous parts, against ingress of solid foreign objects and/or ingress of water and verified by standardized test methods 3.135 disruptive discharge phenomena associated with the failure of insulation under electric stress, in which the discharge completely bridges the insulation under test, reducing the voltage between the electrodes to zero or nearly to zero Note 1: The term applies to discharges in solid, liquid and gaseous dielectrics and to combinations of these. Note 2: A disruptive discharge in a solid dielectric produces permanent loss of dielectric strength (nonself-restoring insulation); in a liquid or gaseous dielectric, the loss may be only temporary (self-restoring insulation). Note 3: The term "sparkover" is used when a disruptive discharge occurs in a gaseous or liquid dielectric. The term "flashover" is used when a disruptive discharge occurs over the surface of a solid dielectric in gaseous or liquid medium. The term "puncture" is used when a disruptive discharge occurs through a solid dielectric. 4 Normal and special service conditions Clause 2 of GB/T 11022-2011 is applicable with the following addition: Unless otherwise specified in this standard, metal-enclosed switchgear and controlgear are designed for normal use.

Contents of GB/T 3906-2020

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Normal and special service conditions 5 Ratings 5.1 General 5.2 Rated voltage (Ur) 5.3 Rated insulation level 5.4 Rated frequency (fr) 5.5 Rated normal current and temperature rise 5.6 Rated short-time withstand currents 5.7 Rated peak withstand current 5.8 Rated durations of short circuit 5.9 Rated supply voltage of closing and opening devices and of auxiliary and control circuits (Ua) 5.10 Rated supply frequency of closing and opening devices and of auxiliary and control circuits 5.11 Rated pressure of compressed gas supply for controlled pressure systems 5.12 Rated filling levels for insulation and/or operation 5.101 Ratings of the internal arc classification (IAC) 5.102 Rated cable test voltages 6 Design and construction 6.1 General 6.2 Requirements for liquids in switchgear and controlgear 6.3 Requirements for gases in switchgear and controlgear 6.4 Requirements for use of solid-insulation embedded component in the main circuit of switchgear and controlgear 6.5 Earthing 6.6 Auxiliary and control equipment 6.7 Power operation 6.8 Stored energy operation 6.9 Independent manual operation 6.10 Operation of releases 6.11 Low- and high-pressure interlocking and monitoring devices 6.12 Nameplates 6.13 Interlocking devices 6.14 Position indication 6.15 Degrees of protection provided by enclosures 6.16 Creepage distances for outdoor insulators 6.17 Gas and vacuum tightness 6.18 Liquid tightness 6.19 Fire hazard (flammability) 6.20 Electromagnetic compatibility (EMC) 6.21 X-radiation emission 6.22 Corrosion 6.101 Internal arc fault 6.102 Enclosure 6.103 High-voltage compartments 6.104 Removable parts 6.105 Provisions for dielectric tests on cables 7 Type tests 7.1 General provisions 7.2 Dielectric tests 7.3 Radio interference voltage (r.i.v.) test 7.4 Measurement of the resistance of circuits 7.5 Temperature-rise tests 7.6 Short-time withstand current and peak withstand current tests 7.7 Verification of the degree of protection 7.8 Tightness tests 7.9 Electromagnetic compatibility tests (EMC) 7.10 Additional tests on auxiliary and control circuits 7.11 X-radiation test procedures for vacuum interrupters 7.101 Verification of making and breaking capacities 7.102 Mechanical operation tests 7.103 Pressure withstand test for gas-filled compartments and gas state measurement 7.104 Tests to verify the protection of persons against dangerous electrical effects 7.105 Weatherproofing test 7.106 Internal arc test 7.107 Performance verification test of metal-enclosed switchgear with solid-insulation embedded components as main components in main circuit 8 Routine tests 8.1 General 8.2 Dielectric test on the main circuit 8.3 Tests on auxiliary and control circuits 8.4 Measurement of the resistance of the main circuit 8.5 Tightness test 8.6 Design and visual checks 8.101 Partial discharge measurement 8.102 Mechanical operation tests 8.103 Pressure tests of gas-filled compartments 8.104 Tests of auxiliary electrical, pneumatic and hydraulic devices 8.105 Tests after erection on site 8.106 Measurement of fluid condition after filling on site 9 Guide to the selection of metal-enclosed switchgear and controlgear 9.1 General 9.101 Selection of rated values 9.102 Selection of design and construction 9.103 Internal arc fault 9.104 Summary of technical requirements, ratings and optional tests 9.105 Ratings of earthing circuits 9.106 Ratings for cable testing 10 Information to be given with enquiries, tenders and orders 10.1 General 10.2 Information with enquiries and orders 10.3 Information with tenders 11 Transport, storage, installation, operation and maintenance 11.1 General 11.2 Conditions during transport, storage and installation 11.3 Installation 11.4 Operation 11.5 Maintenance 12 Safety 12.1 General 12.101 Procedures 12.102 Internal arc aspects 13 Influence of the product on the environment Annex A (Informative) Comparison list of equivalent clause numbering of this standard with IEC 62271-200: Annex B (Normative) Internal arc fault — Method to verify the internal arc classification (IAC) Annex C (Informative) Electric shock protection grade of solid-insulation enclosed switchgear and controlgear Annex D (Normative) Method for calculating cross-sectional area of bare conductor according to thermal effect of short-term continuous current Annex E (Normative) Additional requirements for alternating-current metal-enclosed switchgear and controlgear for rated voltages above 3.6 kV and up to and including 40.5 kV for severe climatic conditions Annex F (Normative) Partial discharge measurement Annex G (Informative) Explanatory notes Bibliography