1、BSI Standards PublicationBS 6423:2014Code of practice formaintenance of low-voltageswitchgear and controlgearPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when the documentwas last issued. The British Standards Institution 2014Published by BSI Stan
2、dards Limited 2014ISBN 978 0 580 81343 6ICS 29.130.20The following BSI references relate to the work on this document:Committee reference PEL/17/3Draft for comment 14/30275063 DCPublication historyFirst edition, published October 1983Second (current) edition, published November 2014Amendments issued
3、 since publicationDate Text affectedBS 6423:2014 BRITISH STANDARDContentsForeword ii1 Scope 12 Normative references 13 Terms and definitions 24 Safety 45 Preventive maintenance 96 Corrective maintenance 197 Post-fault maintenance 208 Fitness for purpose assessment and corrective actions 229 Device s
4、ubstitution 26AnnexesAnnex A (normative) Equipment no longer commonly used but which might bepresent in old installations 32Annex B (informative) Diagnostic aids 35Bibliography 36List of tablesTable 1 List of design verifications to be performed 30Summary of pagesThis document comprises a front cove
5、r, an inside front cover, pages i to iv,pages 1 to 36, an inside back cover and a back cover.BRITISH STANDARD BS 6423:2014 The British Standards Institution 2014 null iForewordPublishing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards I
6、nstitution, and came into effect on 30 November 2014. Itwas prepared by Technical Committee PEL/17/3, Low-voltage switchgear andcontrolgear assemblies under the authority of Technical Committee PEL/17,Switchgear, controlgear, and HV-LV co-ordination. A list of organizationsrepresented on these commi
7、ttees can be obtained on request to their secretary.SupersessionThis British Standard supersedes BS 6423:1983, which is withdrawn.Information about this documentThis is a full revision of the standard, and introduces the following principalchanges:null The structure has been revised to include separ
8、ate clauses on preventivemaintenance, corrective maintenance and post-fault maintenance.null A new clause on fitness for purpose assessment and corrective actions hasbeen added.null A new clause on device substitution has been added.The purpose of this standard is to provide guidance on the maintena
9、nce oflow-voltage switchgear and controlgear where technical knowledge andexperience are important in ensuring equipment is kept in an acceptablecondition. It is intended to be suitable for people involved in all stages of themaintenance process, including those responsible for instigating work,esta
10、blishing procedures for undertaking work and those actually completing themaintenance work. It also provides guidance on replacing devices withinassemblies and on the administrative process required to achieve a successfuloutcome. It is strongly recommended that this standard is used, together withs
11、pecific manufacturers instructions, to develop a coherent maintenance strategy.The normally quiescent state of electrical switchgear and controlgear does notautomatically draw attention to incipient faults, deterioration or the potentialdanger that can result from neglect. The need for maintenance i
12、s oftenoverlooked. An organized system of preventive maintenance will facilitatecontinued safe and acceptable operation of an electrical system with theminimum risk of breakdown and consequent interruption of supply.Hazard warningsWARNING. This British Standard calls for the use of substances and/or
13、procedures that can be injurious to health if adequate precautions are nottaken. It refers only to technical suitability and does not absolve the userfrom legal obligations relating to health and safety at any stage.Use of this documentAs a code of practice, this British Standard takes the form of g
14、uidance andrecommendations. It should not be quoted as if it were a specification andparticular care should be taken to ensure that claims of compliance are notmisleading.Any user claiming compliance with this British Standard is expected to be able tojustify any course of action that deviates from
15、its recommendations.BRITISH STANDARDBS 6423:2014ii null The British Standards Institution 2014It has been assumed in the preparation of this British Standard that theexecution of its provisions will be entrusted to appropriately qualified andexperienced people, for whose use it has been produced.Pre
16、sentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Itsrecommendations are expressed in sentences in which the principal auxiliaryverb is “should”.Commentary, explanation and general informative material is presented insmaller italic type, and does not
17、constitute a normative element.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.BRITISH STANDAR
18、D BS 6423:2014 The British Standards Institution 2014 null iiiBRITISH STANDARDBS 6423:2014This page deliberately left blankiv null The British Standards Institution 20141 ScopeThis British Standard gives recommendations and guidance for the maintenanceof low-voltage switchgear and controlgear having
19、 a rated voltage up to andincluding 1000 V a.c. or 1500 V d.c.This standard is applicable to stationary and movable switchgear andcontrolgear with or without an enclosure. It is also applicable to switchgear andcontrolgear for use under special service conditions, possibly with additionalrecommendat
20、ions, for example in ships and rail vehicles.This standard also gives recommendations on safety precautions for personnelcarrying out maintenance. Guidance on the levels of maintenance necessary forand also procedures for the maintenance of the principal components withinequipment is included. Guida
21、nce is also given on the assessment of the on-goingsuitability of equipment.It also gives recommendations on the direct replacement of parts and, wherethis is not possible, guidance on device substitution.This standard is not applicable to switchgear and controlgear used in potentiallyexplosive atmo
22、spheres.NOTE Inspection and maintenance of electrical apparatus in explosive gasatmospheres is covered in BS EN 60079-17.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in thisdocument and are indispensable for its application. For dated references, onl
23、ythe edition cited applies. For undated references, the latest edition of thereferenced document (including any amendments) applies.BS 7671:2008+A2:2013, Requirements for electrical installations IET WiringRegulations. Seventeenth editionBS EN 60422 , Mineral insulating oils in electrical equipment
24、Supervision andmaintenance guidanceBS EN 60947-4-1:2010+A1:2012, Low-voltage switchgear and controlgear Part4: Contactors and motor starters. Section 1: Electromechanical contactors andmotorstartersBS EN 61439-1:2011, Low-voltage switchgear and controlgear assemblies Part 1:General rulesBS EN 61439-
25、2:2011, Low-voltage switchgear and controlgear assemblies Part 2:Power switchgear and controlgear assembliesBS EN 61439-3, Low-voltage switchgear and controlgear assemblies Part 3:Distribution boards intended to be operated by ordinary persons (DBO)BS EN 61439-4, Low-voltage switchgear and controlge
26、ar assemblies Part 4:Particular requirements for assemblies for construction sites (ACS)BS EN 61439-5, Low-voltage switchgear and controlgear assemblies Part 5:Assemblies for power distribution in public networksBS EN 61439-6, Low-voltage switchgear and controlgear assemblies Part 6:Busbar trunking
27、systems (busways)IEC 60050-441:1984, International Electrotechnical Vocabulary Part 441:Switchgear, controlgear and fusesBRITISH STANDARD BS 6423:2014 The British Standards Institution 2014 null 13 Terms and definitionsFor the purposes of this British Standard, the following terms and definitionsapp
28、ly.3.1 switchgear and controlgeargeneral term covering switching devices and their combination with associatedcontrol, measuring, protective and regulating equipment, also assemblies of suchdevices and equipment with associated interconnections, accessories, enclosuresand supporting structuresIEC 60
29、050-441:1984; 441-11-013.2 switchgeargeneral term covering switching devices and their combination with associatedcontrol, measuring, protective and regulating equipment, also assemblies of suchdevices and equipment with associated interconnections, accessories, enclosuresand supporting structures,
30、intended in principle for use in connection withgeneration, transmission, distribution and conversion of electric energyIEC 60050-441:1984; 441-11-023.3 controlgeargeneral term covering switching devices and their combination with associatedcontrol, measuring, protective and regulating equipment, al
31、so assemblies of suchdevices and equipment with associated interconnections, accessories, enclosuresand supporting structures, intended in principle for the control of electricenergy consuming equipmentIEC 60050-441:1984; 441-11-033.4 low-voltage switchgear and controlgear assemblycombination of one
32、 or more low-voltage switching devices together withassociated control, measuring, signalling, protective, regulating equipment, withall the internal electrical and mechanical interconnections and structural partsBS EN 614391:20113.5 equipmentlow-voltage switchgear, controlgear and switchgear and co
33、ntrolgear assemblies3.6 itemany part of the equipment that can be individually considered3.7 maintenancecombination of all technical and administrative actions, including supervisionactions, intended to retain an item in, or restore it to, a state in which it canperform a required function3.8 preven
34、tive maintenancemaintenance carried out at predetermined intervals or according to prescribedcriteria and intended to reduce the probability of failure or the degradation ofthe functioning of an itemNOTE Also known in the industry as preventative maintenance.3.9 corrective maintenancemaintenance car
35、ried out, after recognition of a failure, which intends to put anitem into a state in which it can perform its required functionBRITISH STANDARDBS 6423:20142 null The British Standards Institution 20143.10 post-fault maintenancemaintenance which might be necessary after a circuit protective device h
36、asoperated and, on switchgear, after a specified number of fault clearanceoperations3.11 predictive maintenancemaintenance activity used to anticipate failures and allow corrective actions tobe implemented on a planned basis3.12 inspectionmaintenance action comprising careful scrutiny of equipment o
37、r an item carriedout without dismantling, supplemented by means such as measurement, in orderto arrive at a reliable conclusion as to the condition of an item3.13 examinationmaintenance action comprising careful scrutiny of equipment or an item carriedout with the addition of partial dismantling as
38、required, supplemented bymeans such as measurement, in order to arrive at a reliable conclusion as to thecondition of an item3.14 overhaulmaintenance of an item including examination and replacement or rebuildingNOTE Overhaul can be categorized as:a) minor overhaul or servicing that is limited to lu
39、brication and/or replacementof consumables;b) major overhaul that includes major dismantling and/or replacement ofitems.3.15 operational checkinspection and/or operational test carried out to determine whether an itemfunctions correctly3.16 failuretermination of the ability of the equipment or an it
40、em to perform its requiredfunctionNOTE Failure can be gradual, sudden, partial or complete.3.17 duty holderperson who is responsible for the organisation, control or execution ofmaintenance activities on equipmentNOTE 1 Attention is drawn to the Electricity at Work Regulations 1 which placecertain l
41、egal obligations on a duty holder.NOTE 2 Elements of this responsibility may be delegated to others as required.3.18 instructed persona person adequately advised or supervised by skilled persons to enable him/herto avoid dangers which electricity may createBS 7671:2008+A2:20133.19 skilled persona pe
42、rson with technical knowledge or sufficient experience to enable him/her toavoid dangers which electricity may createBS 7671:2008+A2:2013BRITISH STANDARD BS 6423:2014 The British Standards Institution 2014 null 33.20 competent persona person who possesses sufficient technical knowledge, relevant pra
43、ctical skillsand experience for the nature of the electrical work undertaken and is able atall times to prevent danger and, where appropriate, injury to him/herself andothersNOTE Several years of practice in the relevant technical field may be taken intoconsideration in assessment of professional tr
44、aining.BS 7671:2008+A2:20134 SafetyNOTE Attention is drawn to the Electricity at Work Regulations 1989 1, the Workat Height Regulations 2005 (as amended) 2, and the Manual Handling OperationsRegulations 1992 3. See also BS EN 50110-1 and BS EN 50110-2.4.1 Appropriate skill level for maintenanceThe d
45、uty holder should put in place a system to ensure that maintenance tasksare carried out by people with the appropriate level of competency, i.e. byinstructed persons (see 3.18), skilled persons (see 3.19) or competent persons(see 3.20), as applicable.4.2 Rules and procedures for establishing a safe
46、workingenvironmentNOTE 1 Attention is drawn to the Management of Health and Safety at WorkRegulations 1999 4, which require risk assessment.A risk assessment should be carried out prior to commencing work.For maintenance activities on equipment there should be a written system ofrules and procedures
47、. Everybody involved with maintenance activities should beaware of their existence. The level of detail and complexity of the rules andprocedures should be dependent on the organisation, personnel, workingenvironment and equipment in use.The risk assessment process should be used to ensure that haza
48、rds specific tomaintenance activities have been adequately addressed in the development ofthe associated rules and procedures. For example, different working practicesand competencies are required for work on d.c. systems than are required fora.c. systems.NOTE 2 Different systems of work might be re
49、quired for older equipment whereequipment within a compartment might not be protected to Level IP2X, inaccordance with BS EN 60529, and so present an increased risk of accidental contactwith live parts.Safety rules should set out the principles and practices expected clearly and in aformat that can be understood by those expected to use them.The rules and procedures should reflect the requirements of an overall electricalsafety policy. In most circumstances a policy for work on electrical equipmentrequires equipment to be isolated an
