IEC_60337-1B-1975_scan.pdf

C.D.U./U.D.C.:621.316.542.1/.3+621.316.542.9.027.2-777.001.11.001.2.001.44COMMISSION ELECTROTECHNIQUE INTERNATIONALE(afiliee a IOrganisation Internationale de Normalisation-IS0)NORME DE LA CEIINTERNATIONAL ELECTROTECHNICAL COMMISSION(affiliated to the International Organization for Standardization-ISO)IEC STANDARDPublication 337-1B1975Deuxieme complement a la Publication 337-1(1970)Auxiliaires de commande(appareils de connexion a basse tensionpour des circuits de commande et des circuits auxiliaires,y comprisles contacteurs auxiliaires)Premiere partie:Prescriptions generalesSecond supplement to Publication 337-1(1970)Control switches(low-voltage switching devices for controland auxiliary circuits,including contactor relays)Part 1:General requirementsDroits de reproduction reserves-Copyright-all rights reservedAucune partie de cette publication ne peut tre reproduite ni utilise sous No part of this publication may be reproduced or utilized in anyquelque forme que ce solt et par aucun procede,lectronique ou mca-form or by any means,electronic or mechanical,including photocopyingnique,y compris ia photocopie et les microfilms,sans laccord crit de Iediteur.and microilm,without permission in writing from the publisher.Bureau Central de la Commission Electrotechnique Internationale1,rue de VarembeGeneve,SuisseTEd10VoL.3-INTERNATIONAL ELECTROTECHNICAL COMMISSIONSECOND SUPPLEMENT TO PUBLICATION 337-1(1970)CONTROL SWITCHES(LOW-VOLTAGE SWITCHING DEVICESFOR CONTROL AND AUXILIARY CIRCUITS,INCLUDING CONTACTOR RELAYS)Part 1:General requirementsFOREWORD1)The formal decisions or agreements of the IEC on technical matters,prepared by Technical Committees on which all the NationalCommittees having a special interest therein are represented,express,as nearly as possible,an international consensus of opinion onthe subjects dealt with.2)They have the form of recommendations for international use and they are accepted by the National Committees in that sense.3)In order to promote international unification,the IEC expresses the wish that all National Committees should adopt the text of theIEC recommendation for their national rules in so far as national conditions will permit.Any divergence between the IEC recom-mendations and the corresponding national rules should,as far as possible,be clearly indicated in the latter.PREFACEThis publication has been prepared by Sub-Committee 17B,Low-Voltage Switchgear and Controlgear,of IECTechnical Committee No.17,Switchgear and Controlgear.The first draft,established in April 1972,was amended by the Chairman and the Secretary of SC 17B who tookinto account the comments received,and the second draft was discussed at the meeting held in Paris in 1974.Thefinal draft was submitted to the National Committees for approval under the Six Months Rule in June 1974.The following countries voted explicitly in favour of publication:AustraliaPolandAustriaPortugalBelgiumSouth Africa(Republic of)DenmarkSpainFinlandSwedenFranceSwitzerlandGermanyTurkeyHungaryUnion of SovietIsraelSocialist RepublicsItalyUnited KingdomJapanUnited States of AmericaNetherlandsYugoslavia一5-SECOND SUPPLEMENT TO PUBLICATION 337-1(1970)CONTROL SWITCHES(LOW-VOLTAGE SWITCHING DEVICESFOR CONTROL AND AUXILIARY CIRCUITS,INCLUDING CONTACTOR RELAYS)Part 1:General requirementsADDITIONS TO PUBLICATION 337-1After Clause 2.1.6,add:Comdiional short-cireui crent swich)A value of prospective current which a control switch,protected by a specified current-limiting switching device,can satisfactorily withstand for the operating time of this device under specified conditions of use and behaviour.Note.-For a.c.the conditional short-circuit current is expressed by the r.m.s.value of the ponent.2.1.8 Fused short-circuit current(of a control switch)The conditional short-circuit current when the current-limiting switching device is a fuse.After Clause 4.2.2.2,add:4.2.2.3 Rated conditional short-circuit current(or rated fused short-circuit current)(of a control switch)The value of prospective current which a control switch,protected by a specified current-limiting switching device,can satisfactorily withstand for the operating time of this device under the test conditions specified in Clause 3.Unless otherwise stated by the manufacturer,this value is 1 000 A.Note.-The condition of not more than 1000 A prospective short-circuit current is characteristic for most cases of control circuitsinvolving a control transformer.When the control circuit is fed directly from a source with a higher fault level,it is recommendedthat the manufacturer should be consulted.The characteristics of the current-limiting switching device shall be stated by the manufacturer.Notes 1.-It is assumed that the requirements will remain satisfied for lower values of rated current of a SCPD of the same type andhomogeneous design.2.-The above-mentioned requirements given for a.c.are considered to be adequate for d.c.also.At the end of Clause 8.1,add the following paragraph:d)if appropriate,tests for verification of the rated conditional short-circuit current or of the rated fused short-circuit current(see Clause 8.1.4).