00924856 PDF BRITISH STANDARD BS EN 50187 1997 Gas filled compartments for a c switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV The European Standard EN 50187 199[.]
BRITISH STANDARD Gas-filled compartments for a.c switchgear and controlgear for rated voltages above kV and up to and including 52 kV The European Standard EN 50187:1996 has the status of a British Standard ICS 29.120.60; 29.260 BS EN 50187:1997 BS EN 50187:1997 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee PEL/17, High-voltage switchgear, controlgear and co-ordination committee, to Subcommittee PEL/17/1, High-voltage switchgear and controlgear, upon which the following bodies were represented: ASTA Certification Services Association of Manufacturers Allied to the Electrical and Electronic Industry (BEAMA Ltd.) British Railways Board Copper Development Association ERA Technology Ltd Electricity Association GAMBICA (BEAMA Ltd.) Ministry of Defence Safety Assessment Federation Ltd Transmission and Distribution Association (BEAMA Limited) The following bodies were also represented in the drafting of the standard, through subcomittees and panels: Association of Consulting Engineers British Cable Makers’ Confederation Electrical Installation Equipment Manufacturers’ Association (BEAMA Ltd.) Engineering Equipment and Materials Users Association Institution of Incorporated Executive Engineers This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 March 1997 © BSI 11-1998 The following BSI references relate to the work on this standard: Committee reference PEL/17/1 Draft for comment 93/205510 DC ISBN 580 26917 Amendments issued since publication Amd No Date Comments BS EN 50187:1997 Contents Committees responsible National foreword © BSI 11-1998 Page Inside front cover ii Text of EN 50187 List of references Inside back cover i BS EN 50187:1997 National foreword This British Standard has been prepared by Subcommittee PEL/17/1 and is the English language version of EN 50187:1996 Gas-filled compartments for a.c switchgear and controlgear for rated voltages above kV and up to and including 52 kV including its corrigendum, September 1996 published by the European Committee for Electrotechnical Standardization (CENELEC) Cross-references Publication referred to Corresponding British Standard EN 50052:1986 BS 6878:1988 Specification for high-voltage switchgear and controlgear for industrial use Cast aluminium alloy enclosures for gas-filled high-voltage switchgear and controlgear EN 50064:1989 BS 7315:1990 Specification for wrought aluminium and aluminium alloy enclosures for gas-filled high-voltage switchgear and controlgear EN 50068:1991 BS EN 50068:1991 Specification for wrought steel enclosures for gas-filled high-voltage switchgear and controlgear EN 50069:1991 BS EN 50069:1991 Specification for welded composite enclosures of cast and wrought aluminium alloys for gas-filled high-voltage switchgear and controlgear EN 60298:1996 BS EN 60298:1996 A.C metal-enclosed switchgear and controlgear for rated voltages above kV and up to and including 52 kV EN ISO 000 series BS EN ISO 000 series Quality management and quality assurance standards EN 45020:1993 BS EN 45020:1993 Glossary of terms for standardization and related activities A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages to 8, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover ii © BSI 11-1998 EUROPEAN STANDARD EN 50187 NORME EUROPÉENNE EUROPÄISCHE NORM August 1996 ICS 29.120.60; 29.260.00 Descriptors: Enclosure, high-voltage switching devices, high-voltage metal-enclosed switchgear and controlgear, pressurized enclosure, gas-filled compartments for rated voltages above kV and up to and including 52 kV English version Gas-filled compartments for a.c switchgear and controlgear for rated voltages above kV and up to and including 52 kV Compartiments sous pression de gaz pour appareillage courant alternatif de tensions assignées supérieures kV et inférieures ou égales 52 kV Gasgefüllte Schotträume für Wechselstrom-Schaltgeräte und -Schaltanlagen mit Nennspannungen über kV bis einschließlich 52 kV This European Standard was approved by CENELEC on 1995-11-28 CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels © 1996 Copyright reserved to CENELEC members Ref No EN 50187:1996 E EN 50187:1996 Foreword This European Standard was prepared by the Technical Committee CENELEC TC 17C, High-voltage enclosed switchgear and controlgear The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50187 on 1995-11-28 The following dates were fixed: – latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1996-12-01 – latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 1996-12-01 Contents Introduction Scope Normative references Definitions Materials Design Manufacture and workmanschip Inspection and testing Pressure relief devices Certification and marking Annex A (informative) A-deviations Page 3 4 6 This European Standard is based on the general specifications given in EN 60298:1996 which are however not sufficient to satisfy the conditions for the service allowance of pressurized high-voltage switchgear and controlgear These specifications are appropriate for pressurized high-voltage switchgear enclosures allowing an economic production without sacrificing aspects of safety For unusual shapes dictated by electrical conditions they permit the verification of sound design by proof tests instead of calculations For the time being reference can only be made to published European and international standards as far as they are appropriate for the purpose of production of enclosures to be used in gas-filled switchgear and controlgear The present European Standard has been established as an international specification for the design, construction, testing and certification of pressurized enclosures used in high-voltage switchgear and controlgear This standard follows to that extent also article of the Directive 76/767/EEC National deviations from this European Standard are listed in annex A (informative) © BSI 11-1998 EN 50187:1996 Introduction This standard covers the requirements for the design, construction, testing, inspection and certification of gas-filled compartments for use in AC switchgear and controlgear or for associated gas-filled equipment Special consideration is given to these compartments for the following reasons:– a) The compartments form the containment of electrical equipment, thus their shape is determined by electrical rather than mechanical considerations b) The equipment is operated by competent persons (operators) only c) As the thorough drying of the inert, non-corrosive gas-filling medium is fundamental to the satisfactory operation of the electrical equipment it is checked at the original pressurisation and periodically if applicable For this reasons no internal corrosion allowance is required on the wall thickness of these compartments d) The compartments are subjected to only small fluctuations of pressure as the gas-filling density shall be maintained within close limits to ensure satisfactory insulating and arc-quenching properties Therefore, the compartments are not liable to fatigue due to pressure cycling e) The operating pressure is relatively low For the foregoing reasons, and to ensure the minimum disturbance hence reducing the risk of moisture and dust entering the compartments which would prevent correct electrical operation of the switchgear, no pressure tests shall be carried out after installation and before placing in service and no periodic inspection of the compartment interiors or pressure tests shall be carried out after the equipment is placed in service The compartments comprise parts of electrical equipment not necessarily limited to the following examples: Circuit breakers Switch disconnectors Disconnectors Earthing switches Current transformers Voltage transformers Busbars and connections Cable terminations Gas filled compartments having a design pressure exceeding bar (gauge) or a product pressure × volume exceeding 000 bar litres shall be designed, manufactured and tested in accordance with one or a combination of the following: EN 50052 EN 50064 EN 50068 EN 50069 1.2 Quality assurance The switchgear manufacturer shall be responsible for achieving and maintaining a consistent and adequate quality of product Sufficient examinations shall be made by the compartment manufacturer to ensure that the materials, production and testing comply in all respects with the requirements of this standard and ISO 3834 Inspection by user’s inspectors shall not absolve the switchgear manufacturer from this responsibility to exercise such quality assurance procedures as to ensure that the requirements and intent of this standard are satisfied NOTE Reference should be made to the EN ISO 000 series of standards for quality systems Scope Normative references 1.1 Type of equipment This European Standard incorporates by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision For undated references the latest edition of the publication referred to applies (including amendments) This standard applies to compartments pressurized at a maximum pressure of bar (gauge) and with a maximum product pressure ´ volume of 000 bar litres with inert gases, for example sulphur hexafluoride or nitrogen or a mixture of such gases, used in indoor or outdoor installations of AC switchgear and controlgear with rated voltages above kV up to and including 52 kV where the gas is used principally for its dielectric and/or arc-quenching properties © BSI 11-1998 EN 50187:1996 EN 50052 1986 Cast aluminium alloy enclosures for gas-filled high-voltage switchgear and controlgear EN 50064 1989 Wrought aluminium and aluminium alloy enclosures for gas-filled high-voltage switchgear and controlgear EN 50068 1991 Wrought steel enclosures for gas-filled high-voltage switchgear and controlgear EN 50069 1991 Welded composite enclosures of cast and wrought aluminium alloys for gas-filled high-voltage switchgear and controlgear EN 60298 1996 A.C metal-enclosed switchgear and controlgear for rated voltages above kV and up to and including 52 kV (IEC 298:1990 + corrigendum April 1995 + A1:1994) EN ISO 000 series Quality management and quality assurance standards (ISO 000 series) ISO 3834 1994 Quality requirements for welding EN 45020 1993 General terms and their definitions concerning standardization and related activities (ISO/IEC Guide 2:1991) Definitions 3.1 compartment a part of gas-filled switchgear and controlgear retaining the insulating gas under the prescribed conditions necessary to maintain safely the rated insulation level, protecting the equipment against external influences 3.2 manufacturer individual or body finally responsible for designing and producing the compartment In this standard this is the switchgear manufacturer, even when the compartment is produced by a sub-manufacturer 3.3 design pressure (of a compartment) pressure (gauge) used to determine the design of the compartment It is at least the upper limit of pressure reached within the compartment at the design temperature 3.4 design temperature (of a compartment) highest temperature reached by the compartment which can occur under service conditions This is generally the upper limit of ambient air temperature increased by the temperature rise due to the flow of rated normal current NOTE Solar radiation and other relevant operating conditions shall be taken into account when they have a significant effect on the temperature of the compartment and on the mechanical properties of some materials Similarly, the effects of low temperatures on the properties of some materials shall be considered 3.5 filling pressure (of a compartment) the pressure in bar (gauge) assigned by the manufacturer referred to atmospheric air conditions of 20 °C and 013 hPa at which the gas-filled compartment is filled before being put into service Materials Any suitable materials or combination of materials may be used for the manufacture of compartments, typical examples are: Wrought mild steel Wrought austenitic stainless steel Wrought aluminium Cast aluminium Cast resin The properties of the materials should be taken from the applicable standards The materials properties shall be verified either by a certificate from the supplier or tests carried out by the switchgear manufacturer © BSI 11-1998 EN 50187:1996 Design 5.4 Calculation methods 5.1 General 5.2 Corrosion allowance When the wall and flange thicknesses of the compartment are calculated the permissible design stress shall be taken from 5.8 Because of the various shapes, sizes, and materials used it is not possible to design such compartments using equations from conventional pressure vessel codes, therefore established methods should be used, using the design pressure and the design temperature as defined in 3.3 and 3.4 The compartments are filled in service with a non-corrosive thoroughly dried gas, therefore, no internal corrosion allowance is necessary NOTE Pressure stress due to an internal electrical fault is not a design parameter For the case of arcing due to an internal fault, reference is made to EN 60298:1996 5.3 Design considerations 5.5 Manholes and Inspection openings The geometry of a compartment can be determined by electrical rather than mechanical considerations This constraint can result in a compartment geometry which requires an unacceptable degree of calculation or which cannot be calculated at all In the case of such a compartment or a compartment for which calculations are not made, a proof test in accordance with clause 7.3 is necessary When designing a compartment, account shall be taken of the following, if applicable: a) The possible evacuation of the compartments as part of the filling process For compartments of this type it is usually necessary to evacuate the air before introducing gas pressure, this ensures purity of the gas The evacuated condition is therefore not an operational condition and in most cases compartments designed for internal pressure will be suitable for the evacuated condition without buckling b) The resulting pressure in the event of an accidental leak between compartments having different pressures c) The full differential pressure possible across the compartment wall d) Superimposed loads and vibrations by external effects e) Stresses caused by temperature differences including transient conditions and by differences in coefficients of thermal expansion f) Effects of solar radiation when applicable g) Dynamic stress due to short circuit current When the strength of the compartment or part therefore has not been determined by calculation, proof tests shall be made in order to demonstrate that the permissible design stress is not exceeded at the design pressure and at the design temperature (see 7.3) No manholes or inspection openings are necessary for inspection of the compartment Consideration for design of compartments for gas insulated switchgear prescribed in this clause takes into account that the compartments are subjected to particular operating conditions (see introduction) which distinguish them from parts for compressed air receivers and similar storage vessels © BSI 11-1998 5.6 Design pressure The design is based on the design pressure as defined in 3.3 5.7 Design temperature The selection of material and the determination of the design stress depend upon the highest wall temperature which can be expected during service at the design pressure as defined in 3.4 5.8 Design stress basis The nominal design strength shall be selected from the material standards For castings the nominal design strength of the material without heat treatment shall be used in the heat affected areas of welds For wrought aluminium, parts the nominal design strength in the annealed condition shall be used in the design of welded structures Design stresses can be established either by calculation or proof tests The permissible design stress (fa) at the design pressure and at the design temperature including the safety factor of the appropriate equations is given by: Rm f a = -3,0 where: Rm: Minimum tensile strength of the material at the design temperature taken from the material standard 3,0 is the safety factor The calculation may be made on higher values of tensile strength if the values are guaranteed by a material certification EN 50187:1996 Manufacture and workmanship Manufacture must be carried out in accordance with sound engineering practice Any welding shall be carried out by welders who have successfully carried out welder procedure tests for the particular joint Where automatic machine welding is employed the initial setting of the machine must be verified for each weld configuration by a test specimen before production commences Periodically the performance of the equipment shall be verified by an identical test specimen Inspection and testing 7.1 General Each compartment shall be inspected during construction Sufficient inspections shall be made to ensure, that the materials, construction and testing comply in all respects with the requirements of this standard 7.2 Routine pressure test Pressure tests shall be carried out on all compartments after manufacture Each compartment shall be subjected to a test pressure of 1,3 times the design pressure for at least one minute As far as possible the test should be carried out on completely assembled compartments This does not apply for compartments with rated filling pressure (as per clause 3.5) of 0,5 bar (gauge) and below After this test the compartments shall show no signs of distress or distortion likely to affect the operation of the switchgear 7.3 Proof tests For each design of compartment which is not calculated or where doubt exists regarding the accuracy of the calculations a proof procedure shall be carried out as follows: The proof procedure shall be a pressure withstand test carried out on one compartment for each type of design of representative compartments Because of the variety of versions of compartments in switchgear and controlgear it is not practical or necessary to make pressure withstand tests for every design of compartments, furthermore, the compartments sometimes differ only in regard to individual details which have no influence on the pressure withstand The performance of any particular arrangement may be substantiated by test results from comparable arrangements When proof tests are carried out on compartments which will be subjected to significant superimposed loads in service the effect of these loads shall be simulated during the test Each representative design of compartment shall withstand a pressure of 3,0 times the design pressure for minute During the test the pressure rise shall not exceed 400 kPa/min After the test the compartment may be distorted The test may be carried out without pressure relief devices, if fitted The replacement of pressure relief devices for the pressure withstand test shall not have any effect on the strength of the compartment Compartments having pressure relief devices which are integrated may have the devices supported or replaced during the test providing this does not increase the withstand pressure of the compartment Any compartment surviving the test shall be scrapped Pressure relief devices 8.1 General conditions If necessary, compartments within the scope of this standard shall be provided with protective devices Typical examples are: a) Bursting discs b) Self-closing valves c) Non-self-closing devices d) Integrated pressure relief devices The protective devices shall be constructed, located and installed so that they are accessible for inspection and repair They shall be protected against accidental damage The devices need not be installed directly on the compartment The discharge areas and any connecting ports to or within the compartment shall be of adequate size to permit effective relief in the event of overpressure Pressure relief devices shall be arranged so as to minimize the danger to an operator during the time he is performing his normal operating duties Pressure relief devices may be connected to the compartment or in the gas supply lines of the gas-filling plant In the case of devices fitted to compartments connected to an external source of pressure these shall be designed to limit the pressure to 1,1 × the design pressure In the case of devices fitted in gas supply lines of the gas-filling plant these shall be designed to limit the overpressure to 1,1 times the filling pressure © BSI 11-1998 EN 50187:1996 The nominal opening pressure shall be recorded It might be considered necessary to design the pressure relief device in order to limit the pressure rise in the event of an internal electrical fault Certification and marking 9.1 Design specification, drawings and data sheets Bursting discs can be manufactured from brittle or ductile materials The rupture pressure of the bursting disc should be chosen to ensure long service without premature bursting The disc manufacturer should be consulted The manufacturer shall maintain a technical file of all data associated with the production of the compartments The file shall include drawings, material certificates, welder records, proof test records, etc This file shall be kept available for a period of not less than ten years from the date of completion of the compartments 8.3 Self-closing pressure relief devices 9.2 Certificates Self-closing pressure relief devices shall be of the direct spring loaded type 8.5 Integrated pressure relief devices When requested by the customer on completion of the compartments the manufacturer shall issue a certificate stating that the compartment has been designed, constructed and tested in every respect in accordance with the requirements of this standard Where the design and fabrication activities are carried out by separate companies, each company shall issue a certificate in respect of the work it has performed The final responsibility, however, rests with the switchgear manufacturer Weakend integral parts of the compartments 9.3 Marking 8.2 Bursting discs 8.4 Non-self-closing pressure relief devices Non-self-closing pressure relief devices may include devices which operate by the “breaking bolt” system NOTE The breaking bolt system pressure relief device is one whereby a diaphragm being secured by a bolt or bolts relieves pressure by fracture or bending of the bolt or bolts, the diaphragm being restrained after venting by other bolts or a cover Each compartment which has been pressure tested shall be stamped by visible marking in an area where operating stresses are low, e.g on the outside edge of a flange, or on a permanently attached nameplate to indicate that it has passed the routine pressure test 9.4 Final Inspection An internal and external inspection of the compartments shall be carried out and the certificates and stamping checked prior to dispatch Where possible the inspections shall be carried out on completed compartments © BSI 11-1998 EN 50187:1996 Annex A (informative) A-deviations A-deviation: National deviation due to regulations, the alteration of which is for the time being outside the competence of the CEN/CENELEC member This European Standard falls under Directives 89/106/EEC and 93/38/EEC NOTE (from CEN/CENELEC IR Part 2, 3.1.9): Where standards fall under EC Directives, it is the view of the Commission of the European Communities (OJ No C 59; 1982-03-09) that the effect of the decision of the Court of Justice in case 815/79 Cremonini/Vrankovich (European Court Reports 1980, p 3583)is that compliance with A-deviations is no longer mandatory and that the free movement of products complying with such a standard should not be restricted except under the safeguard procedure provided for in the relevant Directive A-deviations in an EFTA-country are valid instead of the relevant provisions of the European Standard in that country until they have been removed Clause Deviation 2.1 Italy (Ministerial Decree of December 1,1980 and September 10,1981, published in the Gazzetta Ufficiale No 285, 1981-10-16) Gas-filled compartments having a design pressure exceeding 0,5 bar (gauge) or a volume exceeding 000 litres shall be designed to the Italian pressure vessel code for electrical switchgear © BSI 11-1998 BS EN 50187:1997 List of references See national foreword © BSI 11-1998 BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI Ð British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim 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