. . . . . . . . . . . . . . . . . . . . . . Technical Series Electrical installation guide According to IEC International Standards New edition 2005 http://theguide.merlin-gerin.com This guide has been written for electrical Engineers who have to design, realize, inspect or maintain electrical installations in compliance with international Standards of the International Electrotechnical Commission(IEC). “Which technical solution will guarantee that all relevant safety rules are met?” This question has been a permanent guideline for the elaboration of this document. An international Standard such as the IEC60364 “Electrical Installation in Buldings” specifies extensively the rules to comply with to ensure safety and predicted operational characteristics for all types of electrical installations. As the Standard must be extensive, and has to be applicable to all types of products and the technical solutions in use worldwide, the text of the IEC rules is complex, and not presented in a ready-to-use order. The Standard cannot therefore be considered as a working handbook, but only as a reference document. The aim of the present guide is to provide a clear, practical and step-by- step explanation for the complete study of an electrical installation, according to IEC 60364 and other relevant IEC Standards. Therefore, the first chapter (B) presents the methodology to be used, and each chapter deals with one out of the eight steps of the study. The two last chapter are devoted to particular supply sources, loads and locations, and appendix provides additional information. Special attention must be paid to the EMCappendix, which is based on the broad and practical experience on electromagnetic compatibility problems. We all hope that you, the user, will find this handbook genuinely helpful. Schneider Electric S.A. This technical guide is the result of The Electrical Installation Guide is a single document covering the a collective effort. techniques, regulations and standards related to electrical installations. Itis intended for electrical professionals in companies, design offices, Technical advisor: inspection organisations, etc. Serge Volut Design/Technical content: Electrical equipment should be serviced only by qualified electrical Guy Satre-Duplessis maintenance personnel, and this document should not be viewed as sufficient instructions for those who are not otherwise qualified to operate, Illustrations and production: service or maintain the equipment discussed. Although reasonable care AXESS - Valence -France has been taken to provide accurate and authoritative information in this Printing: document, no responsibility is assumed by Schneider Electric for any Les Deux Ponts - France consequences arising from the use of this material. Second edition This new edition has been published to take into account changes in March 2005 techniques, standards and regulations, in particular electrical installation standard IEC60364. Price: 90 € We thank all the readers of the previous edition of this guide for their ISBN : 2-907314-47-5 comments that have helped improve the current edition. N° dépôt légal: 1er semestre 2005 We also thank the many people and organisations, to numerous to name Conseil © SchneiderElectric here, who have contributed in one way or another to the preparation of All rights reserved for all the countries this guide. Foreword Roland Talon, Chairman TC 64 - International Electrotechnical Commission It is generally agreed that electrical equipment will provide the best performance (safety, operation and service life) when it is properly installed, which includes good co-ordination. The task of Technical Committee 64 of the IEC (International Electrotechnical Commission) is to develop and keep up-to-date requirements for electrical installations. TC64 also has a Safety Pilot Function for installations, equipment, products and systems. Delegates from many National Committees work in TC 64, drawn from manufacturers, laboratories, verification bodies, installers, and electrical power supply companies... …with the consequence that IEC Standard 60364 is considered as the definitive document on which to base the design and implementation of an electrical installation. Furthermore the electrical environment is increasingly complex, mainly due to electromagnetic influences and other kinds of disturbances, and the continuous operation of all equipment supplied by the electrical installation has become a fundamental requirement. Consequently designers, installers and consumers need guidance on the selection and installation of electrical equipment. With this in mind, Schneider Electric has developed this Electrical Installation Guide. It has been prepared by engineers from Schneider Electric who are very experienced in electrical installation technology and possess excellent knowledge of consumer problems and requirements, and of IEC Standard 60364 and other relevant IEC standards. Last but not least, this Electrical Installation Guide has adopted the IEC Standard 60364 as a basis and as a result facilitates and favours international trade. As TC 64 Chairman and formerly the representative of French Electrical Contractors on TC64, it is my great pleasure and honour to introduce this guide. I am sure it will prove very useful in the implementation of the provisions of 60364 and in meeting consumers’ concerns. Roland Talon has been with the French Electrical Contractors’ Association (FFIE) for 20 years. He previously worked for electrical contracting companies. During that period, he was deeply involved in many international projects. Roland Talon has been Chairman of IEC TC 64 since2002 as well as chairman of CENELEC TC64. Continuity of supply Type tested switchboards Knowledge at all times of installation status by simple assembly Discrimination Direct connection of Thanks to the use of standard Web technologies, guarantees co-ordination the Canalis KT busbar you can offer your customers intelligent Merlin Gerin switchboards between the operating trunking on the allowing easy access to information: characteristics of serial- Masterpact 3200 A follow-up of currents, voltages, powers, connected circuit- circuit-breaker consumption history, etc. breakers. Should a fault occurs downstream, only the circuit-breaker placed immediately upstream from the fault will trip. SM6 Sepam Masterpact Compact Multi 9 Prisma Plus Medium voltage switchboard Protection relays Protection switchgear Protection switchgear system Modular protection switchgear Functional system for system from 1 to 36 kV from 100 to 6300 A from 100 to 630 A system up to 125 A electrical distribution switchboards up to 3200 A A consistent design of offers from Medium Voltage to Ultra Terminal Guiding tools for more efficient design and implementation of your installations The technical guides CAD software and tools Training The electrical installation guide, The CAD software and tools enhance Training allows you to acquire the Merlin Gerin theswitchboard implementation guide, productivity and safety. expertise (installation design, work with power on, etc.) thetechnical publications or They help you create your installations for increased efficiency and a guarantee of improved “CahiersTechniques” and coordination by simplifying product choice while also customer service. tables all form genuine reference tools complyingwith standards and forthe design of high-performance electrical proper procedures. installations. These guides help you tocomply to installation rules and standards For more details on Guilding System, please consult www.merlingerin.com Schneider Electric - Electrical installation guide 2005 Schneider Electric - Electrical installation guide 2005 General contents A General design - Regulations - B Installed power Connection to the HV utility C distribution network Connection to the LV utility D distribution network Distribution in low-voltage E installations Protection against electric F shocks The protection of circuit G The switchgear H Protection against voltage J surges Power factor correction and K harmonic filtering Detection and filtering of L harmonics Particular sources and loads M Domestic and similar premises N and special locations EMC guidelines Ap A General contents B General design - Regulations - Installed power 1 Methodology B2 2 Rules and statutory regulations B4 3 Installed power loads - Characteristics B10 4 Power loading of an installation B15 5 Power monitoring and control B21 C Connection to the HV utility distribution network 1 Supply of power at high voltage C2 2 Procedure for the establishment of a new substation C14 3 Protection aspect C16 4 The consumer substation with LV metering C22 5 The consumer substation with HV metering C30 6 Constitution of HV/LV distribution substations C35 D Connection to the LV utility distribution network 1 Low voltage utility distribution networks D2 2 Tariffs and metering D16 E Distribution in low-voltage installations 1 LV distribution schemes E2 2 Earthing schemes E17 3 The installation system E30 4 External influences (IEC 60364-5-51) E38 F Protection against electric shocks 1 General F2 2 Protection against direct contact F4 3 Protection against indirect contact F6 4 Protection of goods due to insulation fault F17 5 Implementation of the TT system F19 6 Implementation of the TN system F25 7 Implementation of the IT system F31 8 Residual current differential devices RCDs F38 G The protection of circuits 1 General G2 2 Practical method for determining the smallest allowable G11 cross-sectional area of circuit conductors 3 Determination of voltage drop G23 4 Short-circuit current G27 5 Particular cases of short-circuit current G33 6 Protective earthing conductor G40 7 The neutral conductor G45 H The switchgear 1 The basic functions of LV switchgear H2 2 The switchgear H5 3 Choice of switchgear H10 4 Circuit breaker H11 Schneider Electric - Electrical installation guide 2005 General contents A J Protection against voltage surges 1 General J2 2 Overvoltage protection devices J6 3 Standards J11 4 Choosing a protection device J14 K Power factor correction and harmonic filtering 1 Reactive energy and power factor K2 2 Why to improve the power factor? K5 3 How to improve the power factor? K7 4 Where to install power correction capacitors? K10 5 How to decide the optimum level of compensation? K12 6 Compensation at the terminals of a transformer K15 7 Power factor improvement of induction motors K18 8 Example of an installation before and after power-factor correction K20 9 The effects of harmonics K21 10 Implementation of capacitor banks K24 L Detection and filtering of harmonics 1 The problem: L2 Why is it necessary to detect and eliminate harmonics? 2 Standards L3 3 General L4 4 Main effects of harmonics in installations L6 5 Essential indicators of harmonic distortion and L11 measurement principles 6 Measuring the indicators L14 7 Detection devices L16 8 Solutions to attenuate harmonics L17 M Particular sources and loads 1 Protection of a LV generator set and the downstream circuits M2 2 Uninterruptible Power Supply Units (UPS) M11 3 Protection of LV/LV transformers M24 4 Lighting circuits M27 5 Asynchronous motors M42 N Domestic and similar premises and special locations 1 Domestic and similar premises N2 2 Bathrooms and showers N8 3 Recommendations applicable to special installations and locations N12 Appendix EMC guidelines 1 Electrical distribution Ap2 2 Earthing principles and structures Ap3 3 Implementation Ap5 4 Coupling mechanism and counter-measures Ap14 5 Wiring recommendations Ap20 Schneider Electric - Electrical installation guide 2005 Chapter B General design - Regulations - Installed power B1 Contents 1 Methodology B2 2 Rules and statutory regulations B4 2.1 Definition of voltage ranges B4 2.2 Regulations B5 2.3 Standards B5 2.4 Quality and safety of an electrical installation B6 2.5 Initial testing of an installation B6 2.6 Periodic check-testing of an installation B7 2.7 Conformity (with standards and specifications) of equipment used in the installation B7 2.8 Environment B8 3 Installed power loads - Characteristics B10 3.1 Induction motors B10 3.2 Resistive-type heating appliances and incandescent lamps (conventional or halogen) B12 4 Power loading of an installation B15 4.1 Installed power (kW) B15 4.2 Installed apparent power (kVA) B15 4.3 Estimation of actual maximum kVA demand B18 4.4 Example of application of factors ku and ks B17 4.5 Diversity factor B18 4.6 Choice of transformer rating B19 4.7 Choice of power-supply sources B20 5 Power monitoring and control B21 5.1 Main user’s benefits B21 5.2 From Network Monitoring and Control System to Intelligent Power Equipment B23 5.3 Typical services possibly brought by intelligent equipment compared to other solutions B25 5.4 Technical inputs on communicating systems B26 5.5 Main constraints to take into account to design a communicating or intelligent power equipment B27 Schneider Electric - Electrical installation guide 2005 B - General design - Regulations - 1 Methodology Installed power B2 The study of an electrical installation using this guide requires the reading of all the chapters in the order in which they are presented. Listing of power demands B – General design - Regulations - The study of a proposed electrical installation requires an adequate understanding of Installedpower all governing rules and regulations. The total power demand can be calculated from the data relative to the location and power of each load, together with the knowledge of the operating modes (steady state demand, starting conditions, non simultaneous operation, etc.) From these data, the power required from the supply source and (where appropriate) the number of sources necessary for an adequate supply to the installation are readily obtained. Local information regarding tariff structures is also required to allow the best choice of connection arrangement to the power-supply network, e.g. at high voltage or low voltage level. Service connection This connection can be made at: C – Connection to the HV utility distribution c High Voltage level network A consumer-type substation will then have to be studied, built and equipped. This substation may be an outdoor or indoor installation conforming to relevant standards and regulations (the low-voltage section may be studied separately if necessary). Metering at high-voltage or low-voltage is possible in this case. D - Low-voltage service connections c Low Voltage level The installation will be connected to the local power network and will (necessarily) be metered according to LV tariffs. LV distribution system E - Distribution within a low-voltage installation The whole installation distribution network is studied as a complete system. The number and characteristics of standby emergency-supply sources are defined. Neutral earthing arrangements are chosen according to local regulations, constraints related to the power-supply, and to the type of loads The distribution equipment (panelboards, switchgears, circuit connections, ...) are determined from building plans and from the location and grouping of loads. The type of premises and allocation can influence their immunity to external disturbances. Protection against electric shock F - Protection against electric shock The earthing system (TT, IT or TN) having been previously determined, then the appropriate protective devices must be implemented in order to achieve protection against hazards of direct or indirect contact. Circuits and switchgear G - The protection of circuits Each circuit is then studied in detail. From the rated currents of the loads, the level of short-circuit current, and the type of protective device, the cross-sectional area of circuit conductors can be determined, taking into account the nature of the cableways and their influence on the current rating of conductors. Before adopting the conductor size indicated above, the following requirements must be satisfied: c The voltage drop complies with the relevant standard c Motor starting is satisfactory c Protection against electric shock is assured The short-circuit current Isc is then determined, and the thermal and electrodynamic withstand capability of the circuit is checked. These calculations may indicate that it is necessary to use a conductor size larger than the size originally chosen. H - The switchgear The performance required by the switchgear will determine its type and characteristics. The use of cascading techniques and the discriminative operation of fuses and tripping of circuit breakers are examined. Schneider Electric - Electrical installation guide 2005 B - General design - Regulations - 1 Methodology Installed power B3 Protection against overvoltages J – Protection against overvoltages Direct or indirect lightning strokes can damage electrical equipment at a distance of several kilometers. Operating voltage surges and transient industrial frequency voltage surges can also produce the same consequences.The effects are examinated and solutions are proposed. Reactive energy K - Power factor improvement and harmonic The power factor correction within electrical installations is carried out locally, filtering globally or as a combination of both methods. Harmonics L - Harmonics detection and filtering Harmonics in the network affect the quality of energy and are at the origin of many pollutions as overloads, vibrations, ageing of equipment, trouble of sensitive equipment, of local area networks, telephone networks. This chapter deals with the origins and the effects of harmonics and explain how to measure them and present the solutions. Particular supply sources and loads M - Particular supply sources and loads Particular items or equipment are studied: c Specific sources such as alternators or inverters c Specific loads with special characteristics, such as induction motors, lighting circuits or LV/LV transformers c Specific systems, such as direct-current networks Generic applications N - Domestic and similar premises and special Certain premises and locations are subject to particularly strict regulations: the most locations common example being domestic dwellings. Ecodial software Ecodial software(1) provides a complete design package for LV installations, in accordance with IEC standards and recommendations. The following features are included: c Construction of one-line diagrams c Calculation of short-circuit currents c Calculation of voltage drops c Optimization of cable sizes c Required ratings of switchgear and fusegear c Discrimination of protective devices c Recommendations for cascading schemes c Verification of the protection of persons c Comprehensive print-out of the foregoing calculated design data (1) Ecodial is a Merlin Gerin product and is available in French and English versions. Schneider Electric - Electrical installation guide 2005