BS-5501-2-1977 EN-50015-1977.pdf

BRITISH STANDARD BS 5501-2: 1977 EN 50015 (Reprinted, incorporating Amendment Nos. 1 and 2) Electrical apparatus for potentially explosive atmospheres Part 2: Oil immersion “o” This European Standard EN 50015 was given as from 30 December 1977 the status of a British Standard UDC 621.31 213.34 78:614.833.4/.5:001.4:620.1:62 777 Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5501-2:1977 This British Standard, having been prepared under the direction of the General Electrotechnical Engineering Standards Committee, was published under the authority of the Executive Board on 30 December 1977 © BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference GEL/114 Draft for comment 75/23939 DC ISBN 0 580 09548 7 Cooperating organizations The European Committee for Electrotechnical Standardization (CENELEC), under whose supervision this European Standard was prepared, comprises the National Committees of the following countries. AustriaNetherlands BelgiumNorway DenmarkPortugal FinlandSpain FranceSweden GermanySwitzerland IrelandUnited Kingdom Italy Amendments issued since publication Amd. No.Date of issueComments 3234January 1980 6438March 1990Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5501-2:1977 © BSI 08-1999i Contents Page Cooperating organisationsInside front cover Text of EN 500153 National appendix A6 National appendix BInside back cover Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5501-2:1977 ii © BSI 08-1999 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 2 to 6, 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. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 50015 Edition 1 March 1977 UDC 621.31-213.34-78:614.833.4/.5:001.4:620.1:62-777 Key words: Electrical apparatus potentially explosive atmosphere explosive atmosphere explosion proofing specific requirement oil immersion “o” English version Electrical apparatus for potentially explosive atmospheres Oil immersion “o” Matériel électrique pour atmosphères explosibles Immersion dans lhuile “o” Elektrische Betriebsmittel für explosionsgefährdete Bereiche Ölkapselung “o” This European Standard was accepted by CENELEC on 1 March 1977. The CENELEC members are bound to adhere to the CENELEC Internal Regulations which specify under which conditions this European Standard has to be given, without any alteration, the status of a national standard. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CENELEC General Secretariat or to any CENELEC member. This European Standard is established by CENELEC in three official versions (English, French, German). A translation made by another member under its own responsibility, in its own language, and notified to CENELEC has the same status. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, 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 © Copyright reserved to all CENELEC members Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 50015:1977 © BSI 08-1999 2 IEC Publications referred to in European Standard EN 50015 European Standard referred to in European Standard EN 50015 This European Standard has been prepared by the CENELEC Technical Committee 31. Contents Page Section 1. General 1Scope3 2Definitions3 Section 2. Specific constructional requirements 3Requirements for the construction of all electrical apparatus3 4Supplementary requirements for certain electrical apparatus4 Section 3. Verifications and tests 5Type tests4 Section 4. Marking 6Additional marking4 IEC 56-4 (1972) (3rd edition) High-voltage alternating-current circuit-breakers Part 4 Type tests and routine tests IEC 157-1 (1973) (2nd edition) Low-voltage switchgear and controlgear Part 1 Circuit-breakers IEC 158-1 (1970) (2nd edition) Low-voltage controlgear Part 1 Contactors IEC 292-1 (1969) (1st edition) Low-voltage motor starters Part 1 Direct-on-line (full voltage) a.c. starters with following supplements: 292-1A (1971) they supplement the definitions which are given in European Standard EN 50014 “General requirements”. 2.1 oil immersion “o” a type of protection in which the electrical apparatus or parts of the electrical apparatus are immersed in oil in such a way that an explosive atmosphere which may be above the oil or outside the enclosure cannot be ignited 2.2 oil mineral oil conforming to IEC 296 Section 2. Specific constructional requirements 3 Requirements for the construction of all electrical apparatus 3.1 The electrical apparatus shall be constructed so that deterioration of the oil by dust or humidity coming from the exterior is effectively prevented but so that gas or vapours from the oil can readily escape. 3.2 Devices shall be provided to ensure that accidental loosening of bolts, screws and nuts of electrical and mechanical connections, as well as of plugs and other parts or devices for filling or draining the oil, cannot occur. 3.3 Tanks which have to be lowered for filling purposes shall have a mark on the inside indicating the prescribed oil level in the lowered position. 3.4 Devices shall be provided so that the oil level can be easily checked when the electrical apparatus is in service. NOTEThe use of a dipstick is permissible provided that safety is not affected, that the dipstick cannot be taken completely away from the electrical apparatus, but that it can be cleaned, if necessary. 3.5 Devices indicating the oil level shall comply with the requirements 3.5.1 to 3.5.4. 3.5.1 The highest and the lowest levels permissible in normal service shall be clearly marked, taking into account the effects of temperature. 3.5.2 The construction shall be such that, in case of leakage due to any damage to the indicating device, the oil cannot fall beneath the level at which full safety of the electrical apparatus remains assured. 3.5.3 Transparent parts shall retain their mechanical and optical properties when in contact with the oil. 3.5.4 Inspection windows shall be replaceable and oil-tight. 3.6 The following temperature limits shall not be exceeded. 3.6.1 The temperature of the oil shall not exceed 115 °C if the oil is class I or 105 °C if the oil is class II, according to IEC 296. NOTEThe limits are fixed in order to prevent the oil from altering too rapidly. 3.6.2 The temperature at the surface of the oil or at any point on the surface of the electrical apparatus to which a potentially explosive atmosphere has access shall not exceed the limit specified in European Standard EN 50014 “General requirements”, for the temperature class concerned. Special attention shall be given to apparatus which may have to withstand for short times currents in excess of the rated value (for example, short circuit currents) which are able to influence the surface temperature. In any case the permissible temperature shall not be exceeded. 3.7 All parts capable of producing arcs or sparks in normal service shall in all circumstances be immersed in oil at a depth sufficient to prevent the ignition of an explosive atmosphere which may occur above the oil. This depth shall be at least equal to the value established by tests as described in clause 5, but in no case shall be less than 25 mm. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 50015:1977 4 © BSI 08-1999 3.8 All energized parts which do not produce arcs or sparks in normal service shall either be immersed in oil as specified in 3.7, or be protected by one of the types of protection listed in European Standard EN 50014 “General requirements”. The conductors entering the free surface of the oil in electrical apparatus for a nominal voltage above 1 kV shall be insulated, except for designs where each pole is arranged in a separate enclosure. The insulation of these conductors shall be sufficiently above the maximum permitted oil level and below the minimum permitted oil level and be effected and arranged in a manner to prevent any discharge along the surface of the oil. In addition any possibility of the oil being lost by capillary or siphon action shall be prevented. 3.9 Draining devices and devices to indicate the oil level shall be provided with special fasteners in accordance with European Standard EN 50014 “General requirements”. 3.10 Enclosures containing bare energized parts shall be able to be opened only by the use of a tool. Special fasteners in accordance with European Standard EN 50014 “General requirements” shall be used for electrical apparatus of Group I. 3.11 Plugs for draining holes shall have at least five full threads of engagement even when they are equipped with a seal. They shall assure complete sealing of the oil. 4 Supplementary requirements for certain electrical apparatus 4.1 Switchgear and controlgear 4.1.1 The rated breaking and making capacities of switchgear and controlgear, such as circuit breakers, switches, motor starters, shall be not more than 75 % of the maximum values at which no ignition of the explosive mixture as prescribed in clause 5 has occurred above the oil surface during the tests. 4.1.2 Motor starters, motor controllers and other controlgear that contain resistors or main current windings under oil shall be provided with protective devices for automatically disconnecting the supply current to the electrical apparatus when the temperature of the oil exceeds by 10 K the permissible temperature specified in 3.6.1, where the surface temperature of the oil does not exceed the temperature class according to 3.6.2. These devices shall also interrupt the supply current when the temperature of the surface of the oil exceeds the limit specified in 3.6.2. 4.2 Transformers Non-hermetically sealed oil-immersed transformers shall be provided with an oil expansion vessel and be equipped with protective devices which automatically interrupt the supply current to the transformer if a) there is an internal fault in the transformer; b) the temperature of the oil exceeds the permitted value. Section 3. Verifications and tests 5 Type tests In order to satisfy the requirements of 4.1.1 the tests for making and breaking shall be carried out in accordance with the type test in the appropriate IEC Publications for the apparatus concerned1). The tests shall be carried out with the highest oil level and the lowest level corresponding to a fault in the level gauge, and with a mixture of air and hydrogen of 22 % to 25 % of hydrogen by volume above the oil within the enclosure. Section 4. Marking 6 Additional marking In addition to the marking prescribed in European Standard EN 50014 “General requirements”, the electrical apparatus shall also carry, when appropriate, additional information as follows. 6.1 The making and breaking capacity as determined according to 4.1.1. 6.2 The time and value of the current defined in 3.6.2. 1) For the relevant tests see, for example, IEC 56-4, IEC 157-1, IEC 158-1 and IEC 292-1. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 5blank Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5501-2:1977 6 © BSI 08-1999 National appendix A The United Kingdom participation in the preparation of this European Standard came under the direction of the General Electrotechnical Engineering Standards Committee of BSI. This committee consists of representatives from the following Government departments and scientific and industrial organizations: Associated Offices Technical Committee British Approvals Service for Electric Cables Ltd British Electrical and Allied Manufacturers Association (BEAMA)* British Radio Equipment Manufacturers Association British Steel Corporation Department of Energy Electricity Electric Cable Makers Confederation Electrical Contractors Association Electrical Contractors Association of Scotland Electrical Research Association Electricity Supply Industry in England and Wales Electronic Components Industry Federation Electronic Engineering Association Engineering Equipment Users Association* Health and Safety Executive* Home Office Institution of Electrical Engineers Ministry of Defence National Coal Board* Oil Companies Materials Association* Post Office Telecommunication Engineering and Manufacturing Association (TEMA) The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee involved with the work on this standard: British Industrial Measuring and Control Apparatus Manufacturers Association British Industrial Truck Association CBMPE Council for Electrical Equipment for Flammable Atmospheres (BEAMA) Department of Energy Petroleum (Oil) Department of the Environment Building Research Establishment (Fire Research Station) Department of the Environment Joint Fire Research Organisation of the Department of the Environment and Fire Offices Committee Department of Trade (Marine Division) Lighting Industry Federation Ltd Miners Lamp Manufacturers Association Rotating Electrical Machines Association (BEAMA) Scientific Instrument Manufacturers Association Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 12:23:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5501-2:1977 © BSI 08-1999 National appendix B The British Standards corresponding to the IEC Publications and European Standards listed on page 3 of EN 50015 are as follows: NOTEBS 5311-4:1976 is a related standard to IEC 56-4:1972 and, as the requirements are additional to those in IEC 56-4, may be considered as technically equivalent for the purposes of this standard. Product certification. Users of this British Standard are advised to consider the desirablility of third party certification of produ