1、BRITISH STANDARD BS EN 61921:2003 Power capacitors Low-voltage power factor correction banks The European Standard EN 61921:2003 has the status of a British Standard ICS 31.060.70 BS EN 61921:2003 This British Standard, was published under the authority of the Standards Policy and Strategy Committee
2、 on 27 October 2003 BSI 27 October 2003 ISBN 0 580 42802 8 National foreword This British Standard is the official English language version of EN 61921:2003. It is identical with IEC 61921:2003. The UK participation in its preparation was entrusted to Technical Committee PEL/33, Power capacitors, wh
3、ich 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 sec
4、tion 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.
5、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 the UK interests informed; monitor re
6、lated 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 23 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issu
7、ed. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 61921 NORME EUROPENNE EUROPISCHE NORM July 2003 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central
8、Secretariat: rue de Stassart 35, B - 1050 Brussels 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61921:2003 E ICS 31.060.70 English version Power capacitors Low-voltage power factor correction banks (IEC 61921:2003) Condens
9、ateurs de puissance - Batteries de compensation du facteur de puissance basse tension (CEI 61921:2003) Kondensatorbatterien zur Korrektur des Niederspannungsleistungsfaktors (IEC 61921:2003) This European Standard was approved by CENELEC on 2003-06-01. CENELEC members are bound to comply with the CE
10、N/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
11、 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
12、versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. EN 62912
13、:1300 - - 2 Foreword The text of document 33/387/FDIS, future edition 1 of IEC 61921, prepared by IEC TC 33, Power capacitors, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61921 on 2003-06-01. The following dates were fixed: latest date by which the EN has to be i
14、mplemented at national level by publication of an identical national standard or by endorsement (dop) 2004-03-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2006-06-01 Annexes designated “normative“ are part of the body of the standard. Annexes desi
15、gnated “informative“ are given for information only. In this standard, annexes A, B and ZA are normative and annexes C and D are informative. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61921:2003 was approved by CENELEC as a European Standard
16、without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60060-1 NOTE Harmonized as HD 588.1 S1:1991 (not modified). IEC 60831-2 NOTE Harmonized as EN 60831-2:1996 (not modified). IEC 60931-2 NOTE Harmonized as EN 6093
17、1-2:1996 (not modified). IEC 60931-3 NOTE Harmonized as EN 60931-3:1996 (not modified). IEC 61000-2-2 NOTE Harmonized as EN 61000-2-2:2002 (not modified). IEC 61000-4-1 NOTE Harmonized as EN 61000-4-1:2000 (not modified). _ Page2 EN61921:2003CONTENTS 1 Scope.4 2 Normative references .4 3 Terms and d
18、efinitions .4 4 Marking of a capacitor bank5 5 Guide for design, installation, operation and safety 6 5.1 General .6 5.2 Choice of components.6 5.3 Design.6 5.4 Installation and operation 9 5.5 Safety .11 6 Electromagnetic compatibility .13 6.1 Emission .13 6.2 Immunity .13 6.3 Assemblies incorporat
19、ing electronic equipment .13 7 Tests14 7.1 Classification of tests 14 7.2 Type tests .15 7.3 Routine tests.16 Annex A (normative) Minimum and maximum cross-sections of copper conductors suitable for connections17 Annex B (normative) Method of calculating the cross-sectional area of protective conduc
20、tors with regard to thermal stresses due to currents of short-duration18 Annex C (informative) Typical examples of assemblies 19 Annex D (informative) Formulae for capacitors and installations 20 Annex ZA Normative references to international publications with their corresponding European publicatio
21、ns 23 Page3 EN61921:2003POWER CAPACITORS LOW-VOLTAGE POWER FACTOR CORRECTION BANKS 1 Scope This International Standard is applicable to low-voltage a.c. capacitor banks intended to be used for power factor correction purposes, equipped with a built-in switchgear and controlgear apparatus capable of
22、connecting to or disconnecting from the mains part(s) of the bank with the aim to correct its power factor. Low-voltage power factor correction banks if not otherwise indicated hereinafter and where applicable shall comply with the requirements of IEC 60439-1 and those of IEC 60439-3. 2 Normative re
23、ferences 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. IEC 60439-1:1999, Low-voltage switchgear
24、 and controlgear assemblies Part 1: Type-tested and partially type-tested assemblies IEC 60439-3:1990, Low-voltage switchgear and controlgear assemblies Part 3: Particular requirements for low-voltage switchgear and controlgear assemblies intended to be installed in places where unskilled persons ha
25、ve access for their use Distribution boards IEC 60831-1:1996, Shunt power capacitors of the self-healing type for a.c. systems having a rated voltage up to and including 1 000 V Part 1: General Performance, testing and rating Safety requirements Guide for installation and operation IEC 60931-1:1996,
26、 Shunt power capacitors of the non-self-healing type for a.c. systems having a rated voltage up to and including 1 000 V Part 1: General Performance, testing and rating Safety requirements Guide for installation and operation 3 Terms and definitions For the purpose of this document, the following de
27、finitions, together with the definitions found in IEC 60439-1, IEC 60831-1 and IEC 60931-1 apply. 3.1 low-voltage a.c. capacitor bank combination of one or more low-voltage capacitor units together with associated switching devices and control, measuring, signalling, protective, regulating equipment
28、, etc., completely assembled under the responsibility of the manufacturer with all the internal electrical and mechanical interconnections and structural parts Page4 EN61921:2003NOTE 1 Throughout this standard, the abbreviations “automatic bank” and “assembly” are used for a low-voltage a.c capacito
29、rs automatic or non-automatic bank. NOTE 2 The components of switchgear and controlgear of the automatic bank may be electromechanical or electronic. 3.2 step of capacitor bank step combination of one or more capacitor units switched together 3.3 automatic reactive power regulator controller circuit
30、 designed to calculate the reactive power absorbed by the load connected to the power line and to control the switching on and off of the steps of the automatic bank, in order to compensate for the reactive power NOTE 1 The reactive power is normally calculated at the fundamental frequency. NOTE 2 T
31、he controller may be “built-in” or “free-standing” and has usually to be adjusted for each bank before operation. 3.4 transient inrush current I ttransient overcurrent of high amplitude and frequency that may occur when a capacitor is switched on, the amplitude and frequency being determined by fact
32、ors such as the short- circuit impedance of the supply, the amount of energized capacitance switched in parallel and the instant of the switching 3.5 rated reactive power Q N(of an assembly) total reactive power of an assembly at the rated frequency and voltage, calculated by the total impedance of
33、the bank including reactors, if any 4 Marking of a capacitor bank The following minimum information shall be given by the manufacturer in an instruction sheet or alternatively, on request of the purchaser, on a rating plate to be fixed on the assembly. 1) Manufacturers name or trademark. 2) Identifi
34、cation number or type designation. 3) Date of manufacture, in clear or code form. 4) Rated reactive power, Q Nin kilovars (kvar). 5) Rated voltage, U Nin volts (V). 6) Rated frequency, f Nin hertz (Hz). 7) Minimum and maximum ambient temperatures in degrees Celsius (C). 8) Degree of protection. 9) S
35、hort-circuit withstand strength, in amperes (A). Page5 EN61921:20035 Guide for design, installation, operation and safety 5.1 General Unlike most electrical apparatus, shunt capacitors, whenever energized, operate continuously at full load, or at loads that deviate from this value only as a result o
36、f voltage and frequency variations. Overstressing and overheating shorten the life of a capacitor, and therefore the operating conditions (that is temperature, voltage and current) should be strictly controlled. It should be noted that the introduction of a capacitance in a system might produce unsa
37、tisfactory operating conditions (for example amplification of harmonics, self-excitation of machines, overvoltage due to switching, unsatisfactory working of audio-frequency remote- control apparatus, etc.). Because of the different types of capacitors and the many factors involved, it is not possib
38、le to cover, by simple rules, installation and operation in all possible cases. The following information is given with regard to the more important points to be considered. In addition, the instructions of the manufacturer and the power supply authorities shall be followed. 5.2 Choice of components
39、 The choice of components of an assembly shall be carried out with careful reference to compliance between their ambient air temperature category and that of the assembly itself. 5.3 Design 5.3.1 Power factor correction system enclosed within a main switchboard The equipment needed for the automatic
40、 correction of power factor in an installation, including controller, fuses, switching devices, capacitors and reactors (chokes), can be installed as an integral part of the main switchboard. This equipment can be also installed in a separate shell of the main board or simply as an added part in the
41、 common main switchboard shell. 5.3.2 Free standing power factor correction system The equipment is free standing and usually installed adjacent or close to the main switchboard or relevant sub-board. It generally has a main bus bar arrangement of the required fault level to match the adjacent main
42、switchboard or sub-board or the required fault current of that section of the installation. This bus bar section is bus barred or cabled back to the main supply of the installation. Feeding off this bus bar section is a group of fuses, circuit-breakers or fused switch which are wired to a switching
43、device and then to the capacitor banks. 5.3.3 Automatic power factor correction system with remote mounted capacitors All components except for the capacitors are mounted in the control cubicle. Page6 EN61921:2003The capacitors and the required reactors, if any, are mounted on a remote mounting rack
44、. This arrangement is generally used if there is a problem with space requirements or to allow further dissipation of heat. It is important to note that power factor component equipment such as fuses, capacitors, reactors, etc. generate a significant amount of heat. 5.3.4 Compartmentalization The ge
45、neral arrangement of a power factor correction assembly can be made in sections, which can be arranged in separate compartments or in a single configuration: a) bus bar, main connection and/or main isolation; b) capacitor bank fuses or circuit-breakers and/or contactors; c) reactors for harmonic con
46、trol purposes; d) capacitors; e) control fuses, terminals and controller. 5.3.5 Choice of rated voltage The rated voltage of the capacitor shall be at least equal to the service voltage of the network to which the capacitor is to be connected, account being taken of the influence of the presence of
47、the capacitor itself. In certain networks, a considerable difference may exist between the service and rated voltage of the network, details of which should be furnished by the purchaser, so that due allowance can be made by the manufacturer. This is of importance for capacitor banks, since their pe
48、rformance and life may be adversely affected by an undue increase of the voltage across the capacitor dielectric. If no information to the contrary is available, the service voltage shall be assumed as equal to the rated (or declared) voltage of the network. Where circuit elements are inserted in se
49、ries with the capacitor to reduce the effects of harmonics, etc., the resultant increase in voltage at the capacitor terminals over and above the service voltage of the network necessitates a corresponding increase in the rated voltage of the capacitor. When determining the voltage to be expected on the capacitor terminals, the following considerations shall be taken into account: a) Shunt-connected capacitors may cause a voltage rise from the sour
