BS-EN-62052-21-2004.pdf
BRITISH STANDARD BS EN 62052-21:2004 Incorporating Corrigendum No. 1 Electricity metering equipment (a.c.) General requirements, tests and test conditions Part 21: Tariff and load control equipment The European Standard EN 62052-21:2004 has the status of a British Standard ICS 91.140.50 ? Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 16:36:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 62052-21:2004 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 21 January 2005 © BSI 12 December 2005 ISBN 0 580 45280 8 National foreword This British Standard is the official English language version of EN 62052-21:2004. It is identical with IEC 62052-21:2004. This standard, in conjunction with BS EN 62054-11 supersedes BS EN 61037:1993, and in conjunction with BS EN 62054-21 supersedes BS EN 61038:1993, both of which will be withdrawn on 1 July 2007. The UK participation in its preparation was entrusted to Technical Committee PEL/13, Electricity meters, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 48, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments 15616 Corrigendum No. 1 12 December 2005Correction to supersession details Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 16:36:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD EN 62052-21 NORME EUROPÉENNE EUROPÄISCHE NORM December 2004 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 © 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 62052-21:2004 E ICS 91.140.50 Partially supersedes EN 61037:1992 + A1:1996 + A2:1998 personal safety against effects of excessive temperature; protection against spread of fire; protection against penetration of solid objects, dust and water. All parts, which are subject to corrosion under normal working conditions shall be effectively protected. Any protective coating shall not be liable to damage by ordinary handling, or damage due to exposure to air, under normal working conditions. Tariff and load control equipment shall have adequate mechanical strength and shall withstand the elevated temperature which is likely to occur in normal working conditions. The components shall be reliably fastened and secured against loosening. Page 15 EN 6205221:2004 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 16:36:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI The construction of tariff and load control equipment shall be such as to minimize the risks of short-circuiting of the insulation between live parts and accessible conducting parts due to accidental loosening or unscrewing of the wiring, screws, etc. NOTE For tariff and load control equipment for special use in corrosive atmospheres, additional requirements shall be fixed in the purchase contract (for example, salt mist test according to IEC 60068-2-11). 5.2 Case 5.2.1 Requirements Tariff and load control equipment shall have a case which can be sealed in such a way that the internal parts of the equipment are accessible only after breaking the seal. The case shall be designed according to protective class I or II. The cover shall not be removable without the use of a tool. The case shall be so constructed and arranged that any non-permanent deformation cannot prevent the satisfactory operation of the tariff and load control equipment. Unless otherwise specified, tariff and load control equipment intended to be connected to a supply mains where the voltage under reference conditions exceeds 250 V to earth, and whose case is wholly or partially made of metal, shall be provided with a protective earth terminal. 5.2.2 Mechanical tests The case shall be subjected to the following tests. NOTE The back-up power supply, if any, shall remain connected. 5.2.2.1 Spring hammer test The mechanical strength of the tariff and load control equipment case shall be tested with a spring hammer (test Ehb, see IEC 60068-2-75). The tariff and load control equipment shall be mounted in its normal working position and the hammer shall act on the outer surfaces of the tariff and load control equipment cover and on the terminal cover with a kinetic energy of 0,2 J ± 0,02 J. The result of the test is satisfactory if the tariff and load control equipment case and terminal cover do not sustain damage, which could affect its function and if it is not possible to touch live parts. Slight damage, which does not impair the protection against indirect contact or the penetration of solid objects, dust and water is acceptable. 5.2.2.2 Shock test The test shall be carried out according to IEC 60068-2-27, under the following conditions: tariff and load control equipment in non-operating condition, without the packing; half-sine pulse; peak acceleration: 30 gn; (300 m/s2); duration of the pulse: 18 ms. After the test, the tariff and load control equipment shall show no damage or change of information and shall operate correctly in accordance with the requirements of the relevant standard. Page 16 EN 6205221:2004 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 16:36:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 5.2.2.3 Vibration test The test shall be carried out according to IEC 60068-2-6, under the following conditions: tariff and load control equipment in non-operating condition, without the packing; frequency range: 10 Hz to 150 Hz; transition frequency: 60 Hz; f 60 Hz constant acceleration 9,8 m/s2 (1 g); single point control; number of sweep cycles per axis: 10. NOTE Ten sweep cycles = 75 min. After the test, the tariff and load control equipment shall show no damage or change of information and shall operate correctly in accordance with the requirements of the relevant standard. 5.3 Window If the cover is not transparent, one or more windows shall be provided for reading the display and observation of the operation indicators if fitted. These windows shall be of transparent material, which cannot be removed without breaking the seals. 5.4 Terminals, terminal block(s), protective earth terminal Terminals may be grouped in (a) terminal block(s) having adequate insulating properties and mechanical strength. In order to satisfy such requirements when choosing insulating materials for the terminal block(s), adequate testing of materials should be taken into account. The terminal block shall be so constructed that the tariff and load control equipment during any deformation caused by rated operating conditions shall comply with the insulation requirements and the clearance and creepage distances within this standard. The material of which the terminal block is made shall be capable of passing the tests given in ISO 75-2 for a temperature of 135 °C and a pressure of 1,8 MPa (Method A). The holes in the insulating material, which form an extension of the terminal holes, shall be of sufficient size to accommodate also the insulation of the conductors. The manner of fixing the conductors to the terminals shall ensure adequate and durable contact so that there is no risk of loosening or undue heating. Screw connections transmitting contact force and screw fixings, which may be loosened and tightened several times during the life of tariff and load control equipment shall screw into a metal nut. For tariff and load control equipment with rated breaking currents up to 25 A, when screw-type terminals are used, it shall be possible to connect in each terminal either one conductor, the cross-section of which is at least 1,5 mm2 or two conductors with a cross-section of 1,5 mm2. If a system other than screw-type terminals is used for connection of the conductors, this system shall retain its full efficiency after 20 connections and disconnections. All parts of each terminal shall be such that the risk of corrosion resulting from contact with any other metal part is minimized. Electrical connections shall be so designed that contact pressure is not transmitted through insulating material. Page 17 EN 6205221:2004 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 16:36:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Terminals with different potentials, which are grouped close together, shall be protected against accidental short-circuiting. Protection may be obtained by insulating barriers. Terminals of one output circuit are considered to be at the same potential. The terminals, the conductor fixing screws or the external or internal conductors shall not be liable to come into contact with metal terminal covers. The protective earth terminal, if any, a) shall be electrically bonded to the accessible metal parts; b) should if possible, form part of the tariff and load control equipment base; c) should preferably be located adjacent to its terminal block; d) shall accommodate a conductor having a cross-section at least equivalent to one of the output circuit of the highest rating; e) shall be clearly identified by the earthing symbol (see IEC 60417-5019: Protective earth (ground). After installation, it shall not be possible to loosen the protective earth terminal without the use of a tool. 5.5 Terminal cover(s) The terminals of a tariff and load control equipment, if grouped in a terminal block and if not protected by any other means, shall have a separate cover, which can be sealed independently of the tariff and load control equipment cover. The terminal cover shall enclose the actual terminals, the conductor fixing screws and, unless otherwise specified, a suitable length of the external conductors and their insulation. When the tariff and load control equipment is panel-mounted, no access to the terminals shall be possible without breaking the seal(s) of the terminal cover(s). 5.6 Clearance and creepage distances The clearance and creepage distances between a) any terminal of a circuit with a reference voltage over 40 V; and b) earth, together with terminals of auxiliary circuits with reference voltages below or equal to 40 V shall not be less than stated in Table 1 for tariff and load control equipment of protective class I; Table 2 for tariff and load control equipment of protective class II. The clearance and creepage distances between terminals of circuits with reference voltages over 40 V shall not be less than stated in Table 1. The clearance between the terminal cover, if made of metal, and the upper surface of the screws when screwed down to the maximum applicable conductor fitted shall be not less than the relevant values indicated in Tables 1 and 2. Page 18 EN 6205221:2004 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 16:36:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Table 1 Clearances and creepage distances for insulating encased tariff and load control equipment of protective class I Voltage phase-to-earth derived from rated system voltage V Rated impulse voltage V Minimum clearances mm Minimum creepage distance mm 100 1 500 0,5 1,4 150 2 500 1,5 1,6 300 4 000 3,0 3,2 600 6 000 5,5 6,3 Table 2 Clearances and creepage distances for insulating encased tariff and load control equipment of protective class II Voltage phase-to-earth derived from rated system voltage V Rated impulse voltage V Minimum clearances mm Minimum creepage distances mm 100 2 500 1,5 2,0 150 4 000 3,0 3,2 300 6 000 5,5 6,3 600 8 000 8,0 12,5 The requirements of the impulse voltage test shall also be met (see 7.3.2.2). 5.7 Insulating encased tariff and load control equipment of protective class II Tariff and load control equipment of protective class II shall have a durable and substantially continuous enclosure made wholly of insulating material, including the terminal cover, which envelops all metal parts, with the exception of small parts, for example, name-plate, screws, suspensions, and rivets. If such small parts are accessible by the standard test finger (as specified in IEC 60529) from outside the case, then they shall be additionally isolated from live parts by supplementary insulation against failure of basic insulation or loosening of live parts. The insulating properties of lacquer, enamel, ordinary paper, cotton, oxide film on metal parts, adhesive film and sealing compound, or similar unsure materials, shall not be regarded as sufficient for supplementary insulation. For the terminal block and terminal cover of such a tariff and load control equipment, reinforced insulation is sufficient. 5.8 Resistance to heat and fire 5.8.1 Requirements The terminal block, the terminal cover and the case of the tariff and load control equipment shall ensure reasonable safety against spread of fire. They shall not be ignited by thermal overload of live parts in contact with them. Page 19 EN 6205221:2004 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 16:36:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 5.8.2 Test The test shall be carried out according to IEC 60695-2-10 and IEC 60695-2-11 with the following temperatures: terminal block: 960 °C ± 15 °C; terminal cover and tariff and load control equipment case: 650 °C ± 10 °C; duration of application: 30 s ± 1 s. The contact with the glow wire may occur at any random location. If the terminal block is integral with the base of the tariff and load control equipment, it is sufficient to carry out the test on the terminal block only. 5.9 Protection against penetration of dust and water 5.9.1 Requirements The tariff and load control equipment shall conform to the degree of protection IP51 as given in IEC 60529, but without suction in the equipment. 5.9.2 Tests
