BS-EN-61558-2-2-2007.pdf

british standard bs en 61558-2-2:2007 safety of power transformers, power supplies, reactors and similar products part 2-2: particular requirements and tests for control transformers and power supplies incorporating control transformers the european standard en 61558-2-2:2007 has the status of a british standard ics 29.180 ? bs en 61558-2-2:2007 this british standard was published under the authority of the standards policy and strategy committee on 31 may 2007 bsi 2007 isbn 978 0 580 50707 6 national foreword this british standard was published by bsi. it is the uk implementation of en 61558-2-2:2007. it is identical with iec 61558-2-2:2007. it supersedes bs en 61558-2-2:1998 which is withdrawn. the uk participation in its preparation was entrusted to technical committee pel/96, small transformers. a list of organizations represented on this committee can be obtained on request to its secretary. 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 cannot confer immunity from legal obligations. amendments issued since publication amd. no. datecomments european standard en 61558-2-2 norme europenne europische norm march 2007 cenelec european committee for electrotechnical standardization comit europen de normalisation electrotechnique europisches komitee fr elektrotechnische normung central secretariat: rue de stassart 35, b - 1050 brussels 2007 cenelec - all rights of exploitation in any form and by any means reserved worldwide for cenelec members. ref. no. en 61558-2-2:2007 e ics 29.180 supersedes en 61558-2-2:1998 english version safety of power transformers, power supplies, reactors and similar products - part 2-2: particular requirements and tests for control transformers and power supplies incorporating control transformers (iec 61558-2-2:2007) scurit des transformateurs, alimentations, bobines dinductance et produits analogues - partie 2-2: rgles particulires et essais pour les transformateurs de commande et les alimentations incorporant les transformateurs de commande (cei 61558-2-2:2007) sicherheit von transformatoren, netzgerten, drosseln und dergleichen - teil 2-2: besondere anforderungen und prfungen an steuertransformatoren und netzgerten, die steuertransformatoren enthalten (iec 61558-2-2:2007) this european standard was approved by cenelec on 2007-02-01. 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, bulgaria, cyprus, the czech republic, denmark, estonia, finland, france, germany, greece, hungary, iceland, ireland, italy, latvia, lithuania, luxembourg, malta, the netherlands, norway, poland, portugal, romania, slovakia, slovenia, spain, sweden, switzerland and the united kingdom. foreword the text of document 96/253/fdis, future edition 2 of iec 61558-2-2, prepared by iec tc 96, small power transformers, reactors, power supply units and similar products, was submitted to the iec-cenelec parallel vote and was approved by cenelec as en 61558-2-2 on 2007-02-01. this european standard supersedes en 61558-2-2:1998 + corrigendum february 1998. the main changes consist of updating this part 2-2 in accordance with en 61558-1:2005, and adding power supplies to the scope. this part 2-2 is intended to be used in conjunction with the latest edition of en 61558-1 and its amendments. it is based on en 61558-1:2005. this part 2-2 supplements or modifies the corresponding clauses in en 61558-1, so as to convert that publication into the european standard: particular requirements and tests for control transformers and power supplies incorporating control transformers. where a particular subclause of part 1 is not mentioned in this part 2-2, that subclause applies as far as is reasonable. where this part 2-2 states “addition“, “modification“ or “replacement“, the relevant text of part 1 is to be adapted accordingly. 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) 2007-11-01 latest date by which the national standards conflicting with the en have to be withdrawn (dow) 2010-02-01 in this part 2-2, the following print types are used: requirements proper: in roman type; test specifications: in italic type; explanatory matter: in smaller roman type. in the text of this part 2-2, the words in bold are defined in clause 3. subclauses additional to those in part 1 are numbered starting from 101; supplementary annexes are entitled aa, bb, etc. annex za has been added by cenelec. _ endorsement notice the text of the international standard iec 61558-2-2:2007 was approved by cenelec as a european standard without any modification. _ 2 en 61558-2-2:2007 contents 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 3 en 61558-2-2:2007 scope.4 normative references5 terms and definitions .5 general requirements .6 general notes on tests6 ratings.6 classification7 marking and other information.7 protection against electric shock.8 change of input voltage setting.8 output voltage and output current under load8 no-load output voltage9 short-circuit voltage9 heating.9 short-circuit and overload protection.10 mechanical strength10 protection against harmful ingress of dust, solid objects and moisture.10 insulation resistance, dielectric strength and leakage current 10 construction .10 components .11 internal wiring.11 supply connection and other external flexible cables or cords11 terminals for external conductors .12 provisions for protective earthing 12 screws and connections .12 creepage distances, clearances and distances through insulation.12 resistance to heat, fire and tracking .12 resistance to rusting 12 annexes13 annex za (normative) normative references to international publications with their corresponding european publications.14 safety of power transformers, power supplies, reactors and similar products part 2-2: particular requirements and tests for control transformers and power supplies incorporating control transformers 1 scope replacement: this part of iec 61558 deals with safety aspects of control transformers and power supplies incorporating control transformers such as electrical, thermal and mechanical safety. this part 2-2 is applicable to control transformers and power supplies incorporating both control transformers and electronic circuits. this part 2-2 is not applicable to external circuits and their components intended to be connected to the input terminals, output terminals or socket-outlets of the transformer and power supplies. this part 2-2 does not apply to transformers covered by iec 60076-11. this part 2-2 applies to stationary or portable, single-phase or poly-phase, air-cooled (natural or forced), independent or associated control transformers and power supplies incorporating a control transformer, having a rated supply voltage not exceeding 1 000 v a.c. and rated supply and internal operating frequency not exceeding 500 hz. the rated thermal output does not exceed: 25 kva for single-phase control transformers and power supplies incorporating control transformers; 40 kva for poly-phase control transformers and power supplies incorporating control transformers. this part 2-2 is applicable to control transformers and power supplies incorporating control transformers without limitation of the rated output subject to an agreement between the purchaser and the manufacturer. this part 2-2 is applicable to dry-type transformers. the windings may be encapsulated or non-encapsulated. the no-load output voltage or the rated output voltage does not exceed 1 000 v a.c. or 1 415 v ripple-free d.c. for independent control transformers and independent power supplies incorporating control transformers, the no-load output voltage and / or the rated output voltage is not less than 50 v a.c., or 120 v ripple free d.c. 4 en 61558-2-2:2007 control transformers covered by this part 2-2 are used only in applications where double or reinforced insulation between circuits is not required by the installation rules or by the end product standard. note 1 normally, the control transformers and power supplies incorporating control transformers are intended to be used with equipment to provide voltages different from the supply voltage for the functional requirements of the equipment. the protection against electric shock may be provided (or completed) by other features of the equipment, such as the body. parts of output circuits may be connected to the input circuits or to protective earth. this part 2-2 is applicable to control transformers and power supplies incorporating control transformers associated with specific equipment, to the extent decided upon by the relevant iec technical committees. note 2 attention is drawn to the following: for control transformers and power supplies incorporating control transformers intended to be used in vehicles, on board ships and on board aircraft, additional requirements (from other applicable standards, national rules, etc.) may be necessary; measures to protect the enclosure and the components inside the enclosure against external influences such as fungus, vermin, termites, solar-radiation, and icing should also be considered ; the different conditions for transportation, storage, and operation of the control transformers and power supplies incorporating control transformers should also be considered; additional requirements in accordance with other appropriate standards and national rules may be applicable to control transformers and power supplies incorporating control transformers intended for use in special environments, such as tropical environments. note 3 future technological development of control transformers and power supplies incorporating control transformers may necessitate a need to increase the upper limit of the frequencies, until then this part 2-2 may be used as a guidance document. 2 normative references this clause of part 1 is applicable except as follows: addition: iec 60076-11, power transformers part 11: dry-type transformers 3 terms and definitions this clause of part 1 is applicable except as follows: replacement of the third paragraph: when the term transformer is used from here forward, it covers control transformers and power supplies incorporating control transformer(s) where applicable. addition: 3.1.101 control transformer transformer intended to supply power to control circuits (e.g. controlling, signalling, interlocking, etc.) 5 en 61558-2-2:2007 3.5.101 rated thermal output product of the rated output voltage and the rated output current, or for polyphase transformers, the appropriate factor (e. g. for three-phase transformers 3 ) times the product of the rated output voltage and the rated output current delivered in continuous operation loaded at power factor 1 if the transformer has more than one output winding or/and tapped output winding, the rated output denotes the sum of the products of rated output voltage and rated output current for output circuits intended to be loaded simultaneously. 3.5.102 admissible instantaneous output product of the rated output voltage and the rated instantaneous output current, or for polyphase transformers, the appropriate factor (e. g. for three-phase transformers 3 ) times the product of the rated output voltage and the rated instantaneous output current delivered at power factor 0,5 if the transformer has more than one output winding or/and tapped output winding, the rated output denotes the sum of the products of rated output voltage and rated instantaneous output current for output circuits intended to be loaded simultaneously. 3.5.103 rated instantaneous output current output current for the specific operating conditions at the rated output voltage and the rated supply frequency at power factor 0,5 assigned to the transformer by the manufacturer 4 general requirements this clause of part 1 is applicable. 5 general notes on tests this clause of part 1 is applicable. 6 ratings replacement: 6.101 the rated output voltage shall not exceed 1 000 v a.c or 1 415 v ripple-free d.c. and for independent transformers shall exceed 50 v a.c. or 120 v ripple free d.c. for independent transformers, this output voltage limitation applies even when output windings, not intended for interconnection, are connected in series. 6 en 61558-2-2:2007 6.102 the rated thermal output shall not exceed: 25 kva for single-phase transformers except for transformers subject to an agreement between the purchaser and the manufacturer; 40 kva for polyphase transformers except for transformers subject to an agreement between the purchaser and the manufacturer. 6.103 the rated supply frequency and the internal operating frequency shall not exceed 500 hz. 6.104 the rated supply voltage shall not exceed 1 000 v a.c. compliance with the requirements of 6.101, 6.102, 6.103, and 6.104 is checked by inspection of the marking. 7 classification this clause of part 1 is applicable. 8 marking and other information this clause of part 1 is applicable except as follows: 8.1 c) replacement: the transformers shall be marked with the rated thermal output and the admissible instantaneous output in volt-ampere, separated by an oblique stroke (e.g. 100/300 va); 8.1 d) is not applicable. 8.1 h) replacement: the transformers shall be marked with one of the graphical symbols shown in 8.11. 7 en 61558-2-2:2007 8.11 addition: symbol or graphical symbol explanation or title identification fail-safe control transformer non-short-circuit proof control transformer short-circuit proof control transformer (inherently or non-inherently) addition: 8.101 if transformers are provided with input tappings to allow adjustments to the supply voltage, these tappings shall be marked with the value or the variation (e.g. +5v or 5v) of the input voltage corresponding to the tapping. note if control transformers are provided with input tappings to allow adjustments to the supply voltage, tappings in steps of 5 % are preferred. 9 protection against electric shock this clause of part 1 is applicable. 10 change of input voltage setting this clause of part 1 is applicable. 11 output voltage and output current under load this clause of part 1 is applicable except as follows: 11.1 replacement: when the transformer is connected to the rated supply voltage, at rated supply frequency, and loaded with an impedance at power factor 1 resulting in the rated thermal output at the rated output voltage, the output voltage shall not differ from the rated value by more than 5 %. compliance is checked by measuring the output voltage when steady-state conditions are established. 8 en 61558-2-2:2007 immediately after the transformer is loaded with an impedance resulting in the admissible instantaneous output at the rated output voltage at power factor 0,5 (inductive), the output voltage measured shall not be less than 95 % of the measured voltage at the rated thermal output. note the output voltage measurement for the admissible instantaneous output should be carried out within 50 ms after applying this overload to minimise the effects of supplementary heating of the transformer. for transformers with more than one rated supply voltage, the requirement is applicable for each of the rated supply voltages. 12 no-load output voltage this clause of part 1 is applicable except as follows: addition: 12.101 the no-load output voltage shall not exceed 1 000 v a.c., or 1 415 v ripple-free d.c for independent transformers, this output voltage limitation applies even when output windings, not intended for interconnection, are connected in series. 12.102 the difference between the no-load output voltage and the output voltage under load shall not be excessive. the difference between the no-load output voltage measured in this clause and the output voltage under load measured during the test of clause 11, expressed as a percentage of the latter voltage, shall not exceed 10 %. note the ratio is defined as follows: uu u no-loadload load 100 (%) where uno-load is the no-load output voltage and uload is the output voltage under load. compliance with the requirements of 12.101 and 12.102 is checked by measuring the no-load output voltage when at ambient temperature, the transformer being connected to the rated supply voltage at the rated supply frequency and at the rated thermal output. 13 short-circuit voltage this clause of part 1 is applicable. 14 heating this clause of part 1 is applicable except as follows: 9 en 61558-2-2:2007 14.1 replace the tenth paragraph by the following: transformers are supplied at the rated supply voltage and loaded with an impedance producing the rated thermal output, at the rated output voltage and, for a.c. current, at the rated power factor. the value of the output current is measured when steady state is established. then the supply voltage is increased by 10 % and the output current is adjusted to the same value measured before. the output current is not adjusted for independent transformers. after this, no change