StandardsInstallation and protection against electrical shocks standardsThe set of IEC 60364-x series of standards defines the main principles and rules on:IEC60364-1: Fundamental principles, assessment of general characteristics, definitionsIEC60364-4-41: Protection for safety - Protection against electric shockIEC60364-5-51: Selection and erection of electrical equipment - Common rules, whose above are extract of the series.Switchgear and controlgear assemblies standardsThe former series of standards (IEC 60439-x), as follow:IEC 60439-1: General rulesIEC 60439-2: Busbar trunking systems (bussways)IEC 60439-3: Distribution boards (DBO)IEC 60439-4: Assemblies for construction sites (ACS)IEC 60439-5: Assemblies for power distribution in public networksis now withdrawn, or under withdrawalNew IEC series of standards is now IEC 61439-x (Low-voltage switchgear and controlgear):IEC61439-1: General rules (published)IEC 61439-2: Power Switchgear and Controlgear (PSC) (published)IEC 61439-3: Distribution boards intended to be operated by ordinary persons (DBO) (published)IEC 61439-4: Assemblies for construction sites (ACS) (publication forecasted 2013)IEC 61439-5: Assemblies for power distribution in public networks (published)IEC 61439-6: Busbar trunking systems (busways) (published)IEC 61439-7: Assemblies for specific installations at public sites such as marinas, camping sites, market squares and similar applications and for charging stations for Electrical Vehicles (publication forecasted 2013)Enclosures standards* IEC 62208 / EN 50298: Empty enclosuresSwitchgear and controlgear devices or functions standards* Low-voltage switchgear and controlgear standard series is IEC 60437-x:IEC 60947-1: General rulesIEC 60947-2: Circuit-breakersIEC 60947-3: Switches, disconnectors, switch-disconnectors and fuse-combination unitsIEC 60947-4-1: Contactors and motor-starters - Electromechanical contactors and motor-startersIEC 6947-4-2: Contactors and motor-starters - AC semiconductor motor controllers and startersIEC 6947-6-1: Multiple function equipment - Transfer switching equipment,whose above are an extract of the series.There are 3 international organisations, working together when needed.IEC (International Electrical Commission)http://www.iec.chThe IEC is the world organization of more 80 countries members that prepares and publishes international standards for all electrical, electronic and related technologies.The purpose of the IEC is to promote international cooperation on all questions concerning standardisation in the electrical and electronic fields. To that end, the IEC publishes International Standards. Their preparation is entrusted to technical committees and any IEC National Committee interested in the subject dealt with may participate in the preparatory work.ITU (International Telecommunication Union)http://www.itu.intITU is an international organization within which governments and the private sector coordinate global telecom networks and services.The ITU is the leading publisher of telecommunication technology, regulatory and standards information.ISO (International Organization for Standardization)ISO is a world wide organisation dealing with all other topics (i.e. automotive, food, mechanical, quality, management, conformity assessment, sustainable development, environment.)

IEC 60439-1: General rules

Standard-UK11/13/07Due to be printed for January 1st 2008 and coming into effect July 1st 2008, firstly, the 17th Edition will be produced with a red cover. It will also feature IEC numbering and will align with CENELEC. This article, the basis of which is information provided by The IET, looks at the changes in the 17th Edition, compared with the 16th Edition:BS 7671: 2008 Requirements for Electrical Installations, IEE Wiring Regulations 17th Edition is scheduled to be issued on January 1st 2008 and is intended to come into effect six months later. The 17th Edition will be completely restructured compared to the present 16th Edition and includes changes necessary to maintain technical alignment with CENELEC harmonisation documents. The new edition will adopt the IEC numbering system. In addition, the layout and parts will be completely revised; for example, many of the chapters will be completely rewritten. The current Part 6 (special locations) will become Part 7 to align with IEC. The next edition of BS 7671 will include additional sections on special locations not currently included in BS 7671 and the existing special locations will be revised to align with changes in CENELEC harmonisation documents.What's new in brief?There are added requirements to protect against voltage disturbances and implement measures against electromagnetic influences. There are also added requirements for safety services, such as emergency escape lighting, and fire protection applications.There is now a requirement that an assessment shall be made for each circuit of any need for continuity of service considered necessary during the intended life of the installation.There is a new concept of protection. The terms protection against direct contact becomes basic protection, and protection against indirect contact becomes fault protection.Socket- outlets up to 20A for use by ordinary persons require 30mA RCD protection and socket-outlets up to 32A for mobile equipment for use outdoors require 30mA RCD protection, but certain exceptions are permitted.There are new additional requirements for the connection of low voltage gensets including SSEGs in Chapter 55 (Section 551).Section 559 on luminaires and lighting installations is a new series of regulations concerning lighting installations. It also includes highway power supplies and street furniture, previously in Part 6.There are now requirements for emergency escape lighting and fire protection applications, and there are also changes to inspection and testing. In addition, changes have been made to the requirements for insulation resistance - when testing SELV and PELV circuits at 250 V, the minimum insulation resistance is raised to 0.5 M; for systems up to and including 500 V, (including FELV), the minimum insulation resistance is raised to 1.0 M.The changes in more detail:41 - Protection against electric shock now includes 471.42 - Protection against thermal effects now includes 48.43 - Protection against overcurrents now includes 473.44 - Protection against voltage disturbances and electromagnetic effects includes 45. It also includes a new section: 442 - Protection of the low voltage installation against temporary overvoltages due to earth faults in the high voltage system and due to faults in the low voltage system.444 - Protection against electromagnetic effects is to be included in amendment 1.53 - is now Protection, isolation, switching control and monitoring, and now includes46, 476 and 537. 534 - Surge protection devices is to be included in amendment 1.54 - Earthing arrangements and protective conductors now includes 607 - Highprotective conductor currents.55 Other equipment includes 559 - Luminaires and lighting installationsParts 6 and 7. Part 6 is now Inspection and testing. Part 7 is Special locationsNotes and Informative Appendices are now included.No limitation of discharge of energy, no alternative method, no mixed disconnection times, no equipotential zone concept.New definitions:Basic protection: Protection against electric shock under fault-free conditions.Fault protection: Protection against electric shock under single fault conditions.Chapter 41Chapter 41 has a new structure and includes the two new definitions, Basic and Fault protection.Four protective measures for common applications:Automatic disconnection of supply.Double or reinforced insulation.Electrical separation for supply to one item of current-using equipment.Extra-low voltage (SELV and PELV).For (i) Disconnection times are now 0.2, 0.4, 1 and 5 seconds. Table 41.1 - 0.4 seconds for all TN final circuits.Additional protection is now required for all socket-outlets for automatic disconnection of supply.In AC systems, additional protection will be by means of an RCD (having In not exceeding 30mA) shall be provided for:Socket outlets not exceeding 20A rating for use by ordinary persons and intended for general use, and mobile equipment not exceeding 32A rating for use outdoors.Mobile equipment not exceeding 32A rating for use outdoors.An exception is permitted for:Socket-outlets for use under supervision of skilled or instructed persons; eg: in some commercial or industrial locations, orA specific labeled, or otherwise suitably identified, socket-outlet provided for connection of a particular item of equipment.Earth rod suggested.230 V now, not 240 V for Tables 41.2 to 41.4.New Table 41.5 for RCDs.ADRLV is retained.SELV and PELV and FELV changed. FELV is recognised. The requirements are clearer. Ostacles, placing out of reach, non-conducting location and electrical separation for more than one item are now at the end of Chapter 41.Chapter 51 - Requires warning notices for SSEGs.Chapter 52 - Changes for concealed cables and new requirements for metal partitions. Voltage drops are now 3% for lighting and 5% for other uses, as defined by Appendix 12.Changes for reduction factors for thermal insulation in Table 52.2 are to recognise improved insulating materials.Section 551 - SSEGs recognised. An SSEG should be installed at the origin or into a final circuit but conductors must be sized, no plug and socket. An RCD must disconnect all live conductors, including the neutral conductor. The line and neutral conductors must not be connected to earth, and disconnection must still occur within the required time.Section 559 This is new. Lighting, including low voltage, outdoor lighting, street lighting (ex 611) and extra-low voltage lighting.Part 6 - Insulation resistance values have been changed. Now, at least 1 Megohm is required for 230/400 VAC systems.Changes to the Existing Requirements for Special Locations:The current special locations contained in the IEE Wiring Regulations are revised to align with the latest IEC and CENELEC standards. So the existing and new(n) part 7s are, more specifically:701 - Locations containing a bath or shower.There is no Zone 3, and zones have been simplified. No supplementary equipotential bonding is required in bathrooms. Socket-outlets are allowed in bathrooms, but must be 3m from the boundary of Zone 1. All circuits need 30mA RCD protection.The 17th Edition will include additional sections on special locations not currently included as follows:702 - Swimming pools and other basins.The requirements for swimming pools now include fountains and the zones have changed from A, B, and C to 0, 1, and 2; ie: zones in swimming pools are now numeric, not alphabetic. There has been a simplification of lighting issues.703 - Rooms and cabins containing sauna heaters. This covers all saunas (not just hot air). Zones are now 1, 2 and 3.704 - Construction and demolition site installations.Now, covers both construction and demolition sites. The reduced disconnection times and 25V equation no longer appear.705 - Agricultural and horticultural premises. No 25V or reduced disconnection times.706 - Conducting locations with restricted movement.708 - Electrical installations in caravan/camping parks and similar locations. (Currently Division Two 608).709(n) - Marinas and similar locations.There are particular risks associated with electrical installations in marinas. The environment of a marina or yachting harbour is harsh for electrical equipment. The water, salt and movement of structures accelerate deterioration of the installation. The presence of salt water, dissimilar metals and a potential for leakage currents increases the rate of corrosion. There are also increased electric shock risks associated with a wet environment by reduction in body resistance and contact with earth potential.711(n) - Exhibitions, shows and stands. There are particular risks associated with exhibitions, shows and stands. These arise from:The temporary nature of the installation.Lack of permanent structures.Severe mechanical stresses.Access to the general public.712(n) - Solar photovoltaic (pv) power supply systems.717(n) - Mobile or transportable units.721 -Electrical installations in caravans and motor caravans. In caravan/camping parks, each socket outlet must now be individually protected with overcurrent and RCD protection.740(n) - Temporary electrical installations for structures, amusement devices and booths at fairgrounds, amusement parks and circuses.753(n) - Floor and ceiling heating systems.Changes to Appendices:Appropriate changes have been made to the existing Appendices 1 to 7. In addition, new Appendices are now included:Appendix 1 - British Standards to which reference is made in the regulations.Appendix 2 - Statutory regulations and associated memoranda.Appendix 3 - Time/current characteristics of overcurrent protective devices - now includes 1 sec disconnection information.Appendix 4 - Current-carrying capacity and voltage drop for cables and flexible cords. Reference methods now A, B, C etc (not numbered). Values up to 1000 mm2. More details for twin and earth.Appendix 5 - Classification of external influences.Appendix 6 - Model forms for certification and reporting.Appendix 7 - Harmonised cable core colours.Appendix 8 - Current-carrying capacity and voltage drop for busbar trunking and powertrack systems.Appendix 9 Definitions - multiple source, DC and other systems.Appendix 10 - Protection of conductors in parallel against overcurrent.Appendix 11 - Harmonic currents in three-phase systems.Appendix 12 - Voltage drop in consumers' installations.Appendix 13 - Methods for measuring insulation resistance of floors and wallsAppendix 14 - Measurement of fault loop impedance: increase of resistance of conductors with temperature.Appendix 15 - Radial and ring final circuit arrangements.

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