IEC_60364-5-537-1981_scan.pdf

6C.D.U./U.D.C.:621.316.172-744.001.25621.316.542/.545.001.25614.825.001.25COMMISSION ELECTROTECHNIQUE INTERNATIONALENORME DE LA CEIINTERNATIONAL ELECTROTECHNICAL COMMISSIONIEC STANDARDPublication 364-5-537Premiere edition-First edition1981Installations electriques des batimentsCinquieme partie:Choix et mise en euvre des matriels lectriquesChapitre 53:AppareillageSection 537-Dispositifs de sectionnement et de commandeElectrical installations of buildingsPart 5:Selection and erection of electrical equipmentChapter 53:Switchgear and controlgearSection 537-Devices for isolation and switchingMots cles:installations electriques des batiments;Key words:electrical installations in buildings;mesures de protection pour lesprotective measures for indoorinstallations;safety requirements;installations dinterieur;exigences de securite;devices for isolation and switching;dispositifs de commande et deelectrical safety requirements.sectionnement;exigences desecurite electrique.Droits de reproduction reserves-Copyright-all rights reservedAucune partie de cetme publication ne peut etre reproduite ni utilisie sous quelque forme No part of this publication may be reproduced or uilized in any form or by any means,que ce soit et par aucun procede,electronique ou mecanique,y compris la photocopie elecronic or mechanical,including photocopying and microfilm,without permision inet les microfilms.sans leccord ecrit de Iediteur.writing from the publisher.Bureau Central de la Commission Electrotechnique Internationale1 rue de VarembeGeneve,SuisseId Frs.17.VOL113INTERNATIONAL ELECTROTECHNICAL COMMISSIONELECTRICAL INSTALLATIONS OF BUILDINGSPart 5:Selection and erection of electrical equipmentChapter 53:Switchgear and controlgearSection 537-Devices for isolation and switchingFOREWORD1)The formal decisions or agreements of the IEC on technical matters,prepared by Technical Committees on which all theNational Committees having a special interest therein are represented,express,as nearly as possible,an internationalconsensus of opinion on the subjects dealt with.2)They have the form of recommendations for international use and they are accepted by the National Committees in thatsense.3)In order to promote international unification,the IEC expresses the wish that all National Committees should adopt thetext of the IEC recommendation for their national rules in so far as national conditions will permit.Any divergencebetween the IEC recommendation and the corresponding national rules should,as far as possible,be clearly indicated inthe latter.PREFACEThis standard has been prepared by IEC Technical Committee No.64:Electrical Installations of Buildings.Drafts of this standard were discussed at the meetings held in Moscow in 1977 and in Sydney in 1979.As a result of thelatter meeting,a draft,Document 64(Central Office)81,was submitted to the National Committees for approval under the SixMonths Rule in September 1979.The National Committees of the following countries voted explicitly in favour of publication:ArgentinaKorea(Republic of)AustraliaNetherlandsAustriaPolandBelgiumRomaniaCanadaSouth Africa(Republic of)ChinaSwedenDenmarkSwitzerlandEgyptTurkeyIsraelUnion of Soviet Socialist RepublicsItalyUnited KingdomJapanUnited States of AmericaIn addition,the wording of Sub-clause 537.4.3,Document 64(Central Office)97,was circulated for approval under the TwoMonths Procedure in September 1980.The National Committees of the following countries voted explicitly in favour of publication:AustraliaNew ZealandBelgiumPolandCanadaRomaniaDenmarkSpainEgyptSwedenFranceSwitzerlandGermanyTurkeyItalyUnion of Soviet Socialist RepublicsJapanUnited KingdomNetherlandsUnited States of America5ELECTRICAL INSTALLATIONS OF BUILDINGSPart 5:Selection and erection of electrical equipmentChapter 53:Switchgear and controlgearSection 537-Devices for isolation and switching53.SWITCHGEAR AND CONTROLGEAR537.DEVICES FOR ISOLATION AND SWITCHING537.1 GeneralAny device for isolation and switching according to Sections 462 to 465 shall comply withthe relevant requirements.If a device is used for more than one function,it shall comply withthe requirements for each of these functions.Note.-In certain instances,additional requirements may be necessary for combined functions.537.2 Devices for isolation537.2.1 The devices for isolation shall effectively isolate all live supply conductors from the circuitconcerned,subject to the provisions of Clause 461.2.Equipment used for isolation shall comply with Sub-clauses 537.2.1.1 to 537.2.5.537.2.1.1 The isolation distances between contacts or other means of isolation,when in the openposition,shall be no less than those specified in the following table.TABLE 53AMinimum isolating distances(Under consideration.)537.2.1.2 The isolating distance between open contacts of the device shall be visible or be clearlyand reliably indicated by Offor Openmarking.Such indication shall only occur when theisolating distance between open contacts on each pole of the device has been attained.Note.-The marking required by this sub-clause may be achieved by the use of the symbolsOandIto indicatethe open and closed positions respectively.537.2.1.3 Semiconductor devices shall not be used as isolating devices.537.2.2 Devices for isolation shall be designed and/or installed so as to prevent unintentionalclosure.Note.-Such closure might be caused for example by shocks and vibrations.7537.2.3 Provision shall be made for securing off-load isolating devices against inadvertent andunauthorized opening.Note.-This may be achieved by locating the device in a lockable spaceor enclosure or by padlocking.Alternatively,the off-load device may be interlocked with a load-breaking one.537.2.4 Means of isolation shall preferably be provided by a multipole switching device whichdisconnects all poles of the relevant supply but single-pole devices situated adjacent to eachother are not excluded.Note.-Isolation may be achieved,for example,by means of:-disconnectors(isolators),switch-disconnectors,multipole or single-pole;-plugs and socket outlets;-fuse-links;-links;-special terminals which do not require the removal of a wire.537.2.5 All devices used for isolation shall be clearly identified,for example by marking,toindicate the circuit which they isolate.537.3 Devices for switching-off for mechanical maintenance537.3.1 Devices for switching-off for mechanical maintenance shall be inserted preferably in themain supply circuit.Where for this purpose switches are provided,they shall be capable of cutting off the full-load current of the relevant part of the installation.They need not necessarily interrupt all liveconductors.Interruption of a control circuit of a drive or the like is permitted only where-supplementary safeguards,such as mechanical restrainers,or-requirements of an IEC specification for the control devices used,provide a condition equivalent to the direct interruption of the main supply.Note.-Switching-off for mechanical maintenance may be achieved,for example,by means of:-multipole switches;-circuit breakers;-control switches operating contactors;-plugs and sockets.537.3.2 Devices for switching-off for mechanical maintenance or control switches for such devicesshall require manual operation.The clearance between open contacts of the device shall be visible or be clearly and reliablyindicated by off or“open marking.Such indication shall only occur when the off oropen position on each pole of the device has been attained.Note.-The marking required by this sub-clause may be achieved by the use of the symbols O and I to indicate.the open and closed positions respectively.537.3.3 Devices for switching-off for mechanical maintenance shall be designed and/or installed soas to prevent unintentional closure.Note.-Such closure might be caused for example by shocks and vibrations.537.3.4 Devices for switching-off for mechanical maintenance shall be placed and marked so as tobe readily identifiable and convenient for their intended use.9537.4 Devices for emergency switching(including emergency stopping)537.4.1 The devices for emergency switching shall be capable of breaking the full-load current ofthe relevant parts of the installation taking account of stalled motor currents whereappropriate.537.4.2 Means for emergency switching may consist of:-one switching device capable of directly cutting off the appropriate supply or-a combination of equipment activated by a single action for the purpose of cutting off theappropriate supply.For emergency stopping,retention of the supply may be necessary,for example,for brakingof moving parts.Note.-Emergency switching may be achieved,for example,by means of:-switches ir the main circuit;push-buttons and the like in the control(auxiliary)circuit.537.4.3 Hand-operated switching devices for direct interruption of the main circuit shall be selectedwhere practicable.Circuit-breakers,contactors,etc.,operated by remote control shall open on de-energizationof coils,or other equivalent failure-to-safety techniques shall be employed.537.4.4 The means of operating(handles,push-buttons,etc.)for devices for emergency switchingshall be clearly identified,preferably coloured red with a contrasting background.537.4.5 The means of operating shall be readily accessible at places where a danger might occurand,where appropriate,at any additional remote position from which that danger can beremoved.537:4.6 The means of operation of a device for emergency switching shall be capable of latching orbeing restrained in the offor stopposition unless both the means of operation foremergency switching and for re-energizing are under the control of the same person.The release of an emergency switching device shall not re-energize the relevant part of theinstallation.537.4.7 Devices for emergency switching,including emergency stopping,shall be so placed andmarked as to be readily identifiable and convenient for their intended use.537.5 Functional switching devices537.5.1 Functional switching devices shall be suitable for the most onerous duty they may be calledupon to perform.537.5.2 Functional switching devices may control the current without necessarily opening thecorresponding poles.Notes 1.-Semiconductor switching devices are examples of devices capable of interrupting the current in the circuitbut not opening the corresponding poles.