EBCS-10: 2013

Ethiopian Building Code Standard _

ELECTRICAL INSTALLATION OF BUILDINGS

2013 Edition

FOREWORD The Proclamation to define the powers and duties of the Central and Regional Executive Organs of the Transitional Government of Ethiopia No. 41/1993 empowers the Ministry of Works and Urban Development to prepare the Country's Building Code, issue Standards for design and construction works, and follow up and supervise the implementation of same.

In exercise of these powers and in discharge of its responsibility, the Ministry is issuing a series of Building Code Standards of general application. The purpose of these standards is to serve as nationally recognized documents, the application of which is deemed to ensure compliance of buildings with the minimum requirements for design, construction and quality of materials set down by the National Building Code. The major benefits to be gained in applying these standards are the harmonization of professional practice and the ensuring of appropriate levels of safety, health and economy with due consideration of the objective conditions and needs of the country. As these standards are technical documents which, by their very nature, require periodic updating, revised editions will be issued by the Ministry from time to time as appropriate. The Ministry welcomes comments and suggestions on all aspect of the Ethiopian Building Code Standards. All feedback received will be carefully reviewed by professional experts in the field of building construction with a view to possible incorporation of amendments in future editions. Mekuria Haile Minister Ministry of Construction and Urban Development 2013

INTRODUCTION This Code Standard for the Electrical Installation of Buildings, EBCS 10: 2013 Edition, is part of the Building Code of Ethiopia which is a revision of the eaerlier EBCS 10: 1995 Edition . EBCS 10 has been mainly adopted and adapted from IEE Regulations for Electrical Installations (Bris=tish origin), Canadian Electrical Code, Part 1; the German standard (DIN and VDE); and National Fire Protection Authority/National Electrical Code (NFPA/NEC) of the USA to suit the Ethiopian conditions. Other publications quoted are shown in the respective sections of the Code and the Ethiopian Standardization Agency maintains registers of a number of foreign national and international standards. The Code embraces several aspects of electrical installation work and sets standards and provisions for safe utilization of electricity. The Technical Committee for the first edition of the Code Standards for the Electrical Installation of Buildings comprised of the then following Institutions representing balanced interest of all segments of the public concerned with the subject matter:

• Ministry of Works & Urban Development (MWUD), now Ministry of Construction & Urban Development (MoCUD) • Building Design Enterprise (BDE) • Ethiopian Electric Light & Power Authority (EELP A), now Ethiopian Electric Power Corporation (EEPCO)] • Addis Ababa University, Faculty of Technology (AAU), now represented by Addis Ababa Institute of Technology (AAiT) • Ethiopian Authority for Standardization (EAS), now Ethiopian Standards Agency For the revision process to come up with EBCS-10: 2013 Edition, MoCUD signed a memorandum of understanding with Addis Ababa University in 2012 which mandated also to involve members from other stakeholders including the industry, private consultants, contractors andgovernment agencies. Accordingly, the Building Electrical Installation Technical Committee (BEITC) has been formed from practical as well as theoretically experienced members from Addis Ababa Institute of Technology (AAiT) of the AAU and a private consultant.

History and Development of the Ethiopian Building Electrical Installation Code and Standard (now referred to as EBCS-10) In the growing Ethiopian practice on building electrical installations, introduced, developed and established over a period extending up to a century since the early 1900s, it appears that electrical installation practices (i.e. both approved and taken for granted) were practically derived from European practices. Henceforth, the design rules and contracting or subcontracting practices were implicitly based first on either on earlier versions of IEC 60 364 standards, or later on and more recently on DIN VDE 0 100 standards and regulations. The first nationally governing regulatory document concerning building electrical installation in Ethiopia has been issued by the then Ethiopian Electric Light and Power Authority(EELPA) under the theme “Building Electrical Installation Regulation ????” in 196??. During that time EELPA had been acting not only as a utility engaged in the generation, transmission, distribution and sales of electric power but also as a regulator of the same as well as building electrical installations. This first regulatory document, produced by EEPCO, has been very limited in scope, coverage and application. This problem initiated the process and paved the way for producing an entirely new and wide code. By far the more wide issues covering, systematized, and standardized document comparable to international similar experiences is the Building Electrical Installation Standard and Code of Ethiopia, referred to as EBCS-10 and developed in 1995. EBCS-10 is an integral part of the Ethiopian Building Code Standard which comprises 11 codes that address the structural, foundational, earthquake etc aspects of a building. EBCS 10 is concerned about only issues of electrical installation in a building. The main purpose of EBCS 10 has been for the safe utilization of electricity in buildings plus embracing several aspects of electrical installation work. Some time in between, the then EELPA has been transformed in to Ethiopian Electric Power Corporation whose activity has been limited to only operational and not regulatory. The regulatory aspect has been entitled to various government agencies through proclamations. As to application, because no formal enforcement mechanisms have been in place, only very few professionals practiced the EBCS-10:1995 Building Electrical Installation Code and Standard while most adhering to international codes and standards. As a result, it has been difficult to do impact analysis of the effect of EBCS10:1995 in the Ethiopian building installation practice. The Ministry of Construction and Urban Development (MoCUD), observing the safety and reliability problems in many buildings associated to electrical installations, initiated the EBCS10:1995 to be revised in 2011 after its 16 years of service. Accordingly EBCS-10: 2013 Edition, a revised version of EBCS10:1995, has been produced.

Preface to EBCS-10: 2013 Edition EBCS-10: 2013 Edition is the updated version of EBCS-10: 1995. In the update process the Building Electrical Installation Technical Committee (BEITC) focused mainly on the following aspects of revision: •

Emphasizing/redefining the purpose/mandate of the EBCS-10 code

•

Using/citing updated and latest versions of the Normative Reference materials that has already been utilized and reflecting the updated information therein in EBCS-10.

•

Incorporation of missing issues requiring codes and standards within the existing 26 sections of the code

•

Introducing additional separate Sections in to the existing code to address some important issues

•

Correction of typographical errors in the previous document of the code

The main purpose of EBCS 10 has been maintained to be primarily for safe utilization of electricity in buildings ensuring the avoidance of fire hazards on humans/animals, buildings and properties therein and thereby as well as shock hazards on humans and animals. Critical issues such as reliability, efficiency, economics as well as the convenience, expansion and maintenance of a building electrical installations have been raised and discussed among the Tehnical Committee. However, centering on the issue of safety makes logically the conductors, devices, apparatuses and other electrical materials to be used to be of relatively higher capacity, higher quality and durable and as a result reliability and efficiency aspects of the installation will be satisfied. However, cost of the installation would increase which should be compromised for the prior agenda of safety of humans and properties. Thus, in the selection and endorsement of the prior Normative References, cost has not been considered. EBCS-10: 1995 and EBCS-10:2013 both are adoptions of codes and standards from Europe, USA and Canada plus some adaptations to local context. This process has been maintained and updated versions of the Normative References have been referred.

NOTICE AND DISCLAIMER OF LIABILITY CONCERNING THE USE OF EBCS-10: 2013 DOCUMENTS The codes, standards, recommended practices, and guides contained in EBCS-10: 2013 are adopted and adapted from known codes such as that of the European (EN) and/or British (BS), the Canadian and the American’s NEC. Accordingly the Building Electrical Installation Technical Committee (BEITC) did not independently test, evaluate, or verify the accuracy of any information or the soundness of any judgments contained in its codes and standards. BEITC disclaims liability for any personal injury, property or other damages of any nature whatsoever, whether special, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this document. BEITC also makes no guaranty or warranty as to the accuracy or completeness of any information published herein. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. BEITC has no power, nor does it undertake, to police or enforce compliance with the contents of this document. Nor does BEITC list, certify, test or inspect products, designs, or installations for compliance with this document. Any certification or other statement of compliance with the requirements of this document shall not be attributable to BEITC and is solely the responsibility of the certifier or maker of the statement. ADDITIONAL NOTICES AND DISCLAIMERS Updating of the EBCS 10 Document Users of EBCS 10:2013 should be aware that the document may be superseded at any time by the issuance of new editions or may be amended from time to time through the issuance of amendments. An official EBCS 10:13 document at any point in time consists of the current edition of the document together with any tentative amendments and any Errata then in effect. . Interpretations of the EBCS 10:2013 Document ….. Patents EBCS 10:2013 does not take any position with respect to the validity of any patent rights asserted in connection with any items which are mentioned in or are the subject of codes, standards, recommended practices, and guides in EBCS 10:2013 and the EBCS 10:2013 disclaims liability for the infringement of any patent resulting from the use of or reliance on these documents. Users of this document are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, is entirely their own responsibility.

EBCS 10:2013 adheres to applicable policies of the Ethiopian Standards Agency or the Intellectual Property and Copyright Protection Authority??? of Ethiopia. Law and Regulations Users of this document should consult applicable federal, state, and local laws and regulations. EBCS 10 does not, by the publication of its codes, standards, recommended practices, and guides, intend to urge action that is not in compliance with applicable laws, and these documents may not be construed as doing so. Copyrights This document is copyrighted by the EBCS. It shall be made available for a wide variety of both public and private uses. These include both use, by reference, in laws and regulations, and use in private self-regulation, standardization, and the promotion of safe practices and methods. By making this document available for use and adoption by public authorities and private users, the MoCUD does not waive any rights in copyright to this document. Use of EBCS10 document for regulatory purposes should be accomplished through adoption by reference. The term “adoption by reference” means the citing of title, edition, and publishing information only. Any deletions, additions, and changes desired by the adopting authority should be noted separately in the adopting instrument.

ETHIOPIAN BUILDING CODE STANDARD

EBCS-10: 2013 ELECTRICAL INSTALLATION OF BUILDINGS S

TABLE OF CONTENTS FOREWORD ……………………………………………………………………………………………………………………………………….. i INTRODUCTION ………………………………………………………………………………………………………………………………….. ii HISTORY AND DEVELOPMENT OF THE ETHIOPIAN BUILDING ELECTRICAL INSTALLATION CODE AND STANDARD …. iii PREFACE TO EBCS-10: 2013 EDITION: ……………………………………………………………………………………………………….. iv NOTICE AND DISCLAIMER OF LIABILITY …………………………………………………………………………………………………. v

SECTION 1 SCOPE AND DEFINITIONS 1.1 Scope ……………………………………………………………………………. 1 1.2 Nonnative references …………………………………………………………… 1 1.3 Definitions ……………………………………………………………………… 2

SECTION 2 GENERAL REQUIREMENTS 2.1 Administrative …………………………………………………………………………20 2.1.1 Authority for rules ……………………….………………………………………20 2.1.2 Permit …………………………………………………………………………… 20 2.1.3 Application for inspection …………….…………………………………………20 2.1.4 Posting of permit ……………………………………………………….………20 2.1.5 Notification re-inspection ………………………………………………………20 2.1.6 Plans and specifications …………………………………………………………21 2.1.7 Connection authorization ………………………………………………………21 2.1.8 Re-inspection … ………….………………………………………………………21 2.1.9 Renovation of existing installation ………………………………………………21 2.1.10 Use of approved equipment ……………………………………………………22 2.1.11 Deviation or postponement ……………………………………………………22 2.1.12 Powers of rejection ………………………………………….…………………22 2.1.13 Installation of electrical equipment ……………………………………………22 2.1.14 Damage and interference ………………………………………………………22 2.2 Technical ………………………………………………..……………………………23 2.2.1 Conventional symbols ………………………………………………..…………23

2.2.2 Co-ordination ……………………………………………..…………..…………23 2.2.3 Location and requirement of substation ……………………………..…………23 2.2.4 Rooms (spaces) required ………………………………………………..…………23 2.2.5 Location and requirements of distribution boards ………………………………24 2.2.6 Location and requirements of PBX/PABX rooms ………………………………24

2.3 Planning and designing …………………………………………………………………25 2.3.1 General ……………………………………………………………………………25 2.3.2 Layout and installation drawing …………………………………………………25 2.3.3 Design ……………………………………………………………………………25 2.4 Marking of equipment ………………………………………………………………… 26 2.4.1 General …………………………………………………………………………… 26 2.4.2 Workmanship and materials ………………………………………………………27 2.4.3 Material for anchoring ……………………………………………………………27 2.4.4 Protection of persons and property ………………………………………………27 2.4.5 Maintainability …………………………………….…………………………….. 27 2.4.6 Enclosures …………………………………………………………..…………… 28

SECTION 3 ILLUMINATION 3.1 Scope ………………………………………………………………….…………………29 3.2 Normative references ……………………………………………………………………29 3.3 Definitions ………………………………………………………………………………30 3.4 Lighting requirements ………………………………………….……………………….35 3.4.1 Illuminance ………………………………………………………………………. 35 3.4.2 Luminance ……………………………………………..………………………….35 3.4.3 Glare …………………………………………………….…………….…………. 36 3.4.4 Light direction and modelling …………………………………………………….36 3.4.5 Colour rendering ………………………………………….……………………….36 3.5 Emergency lighting requirements ………………………………………….……………37 3.5.1 Escape lighting ……………………………………………….……..…………….37 3.5.2 Safety lighting for particular hazardous workplaces ……………………………37 3.5.3 Standby lighting ………………………………………………………………….38

3.6 Lighting requirements for various types of buildings ……………………………………38 3.6.1 General …………………………………………………………………………….38 3.6.2 Industrial ……………………………………………………………….………….39 3.6.3 Offices ……………………………………………………………………………. 39 3.6.4 Hotels and restaurants ……………………………………………………………. 39 3.6.5 Educational establishments …………………………………………………………40 3.6.6 Hospitals …………………………………………………………………………. 40 3.7 Outdoor lighting requirements ………………………………..…………………………42 3.7.1 Illuminance ……………………………………………………….……………….42 3.7.2 Colour rendering group ……………………………………………………………42 3.7.3 Limitation of glare ………………………………………………..……………….43 3.7.4 Lighting of outdoor fixed location work spaces …………………………………43

SECTION 4 CONDUCTORS 4.1 Scope …………………………………………………………………………………….66 4.2 Nonnative references …………………………………………………………………….66 4.3 Definitions ……………………………………………………………………………….67 4.4 Size of conductors ……………………………………………………………………….69 4.4.1 Phase conductors in a.c. circuits and live conductors in d.c. circuits …………... 69 4.4.2 Neutral conductors ………………………………………………………………. 69 4.5 Ampacity of wires, cables and flexible cords ……………………………………………70 4.5.1 Conductor operating temperature …………………………………………………70 4.5.2 Cables connected in parallel ………………………………………………………70 4.5.3 Cables connected to bare conductors or bus bars …………………….……………70 4.5.4 Voltage drop ……………………………………………………………………….70 4.6 Flexible cords ……………………………………………………………………………. 70 4.7 Colour of conductors ………………………………………….………………………….71 4.8 Maximum permissible temperature ………………………………………………………71 Annex (preface) Annex A (Normative) - Correction factors…………………………………...………………74 Annex B (Normative) - Type of cable and ampacity …………………………………………85

SECTION 5 SERVICE AND SERVICE EQUIPMENT ………………………….………………90 5.1 Scope ……………………………………………………………………………………. 141 5.2 Normative references …………………………………………………………………….141 5.3 Definitions ……………………………………………………………………………….141 5.4 General requirements …………………………………………………………………….142 5.4.1 Number of services permitted ……………………………………………………142 5.4.2 Consumer's installation not to be supplied through another building …………….143 5.4.3 Conductors considered outside of a building …………………………………….143 5.4.4 Other conductors in raceway or cable· …………………………………………..144 5.4.5 Clearance from building openings ……………………………………………….144 5.5 Service equipment …………………………………………………….…………………144 5.5.1 General …………………………………………………………………..……….144 5.5.2 Control …………………………………………………………………….……..145 5.6 Wiring methods ………………………………………………………………………….148 5.6.1 Underground consumer's service conductors . ……………………………………148 5.6.2 Overhead consumer's service conductors …………………………………………148 5.7 Metering equipment ……………………………………………………………..……….149 5.7.1 Connection …………………………………………………….………………….149

SECTION 6 CIRCUIT LOADING AND DEMAND FACTOR 6.1 Scope …………………………………………………………………………………….150 6.2 Normative references …………………………………………………………………….150 6.3 Definitions ……………………………………………………………………………….150 6.4 General …………………………………………………….…………………………….151 6.4.1 Current calculation ……………………………………………………………….151 6.4.2 Voltage drop…………………………………………..…………………………. 151 6.4.3 Maximum circuit loading …………………………………………………………151 6.4.4 Use of demand factor ……………………………………………..………………151 6.5 Services and feeders …………………………………………………………………….151 6.5.1 Single-family dwellings …………………………………………………………151

6.5.2 Apartment and similar multi-family buildings ………………….………………. 152 6.5.3 Schools …………………………………………………………………..……….153 6.5.4 Hospitals ………………………………………………………………………….153 6.5.5 Hotels, motels, dormitories, and buildings of similar occupancy ………………..154 6.5.6 Other types of occupancy …………………………………………………………155 6.5.7 Branch circuits …………………………………………………………………….155 6.5.8 Feeder demand factors for lifts ……………………………………………………155

SECTION 7 EARTHING, BONDING, AND LIGHTNING PROTECTION PART I - EARTHING, AND BONDING 7.1 Scope …………………………………………………………………………………..157 7.2 Normative references ……………………………………………………….………….157 7.3 System and circuits earthing ……………………………………………………………158 7.3.1 Direct current. systems ……………………………………………………………158 7.3.2 Alternating - current systems ……………………………………………..………158 7.4 Location of system earthing connections ………………………………………………159 7.4.1 D.C. systems …………………………………………………………………..….159 7.4.2 A.C. systems ……………………………………………………..……………….159 7.4.3 Isolated systems ……………………………………………………….………….159 7.4.4 Single service supply to two or more buildings or structures …………..……….160 7.4,5 Conductors to be earthed …………………………………………………………160 7.4.6 Current over earthing conductor ………………………….………………………160 7.5 Bonding 161 7.5.1 Non-current carrying metal parts ………………………………………………..161 7.5.2 Exposed non-current-carrying metal parts of equipment ………………………..161 7.5.3 Non-metallic wiring systems ………………………………………………….…161 7.5.4 Non-electrical services …………………………………………………….……161 7.5.5 Extraneous fixed metalwork ……………………………………………………164 7.6 Method of earthing ……………………………………………………………………...164 7.6.1 Effective earthing ……………………………………………………………….164 7.6.2 Common earthing conductor ……………………………………………………164 7.6.3 Common earthing electrode ……………………………………………………164 7.6.4 Underground service …………………………………………………………….165

7.6.5 Short section of raceway ……………………………………………………….165 7.6.6 Fixed equipment ……………………………………………………………..….165 7.7 Bonding methods …………………………………………………………..………….166 7.7.1 Clean surface ………………………………………………………………..…. 166 7.7.2 Bonding at service equipment ………………………………………………….166 7.7.3 Means of assuring continuity at service equipment ………………………….. 166 7.7.4 Metal armor or tape of service cable……………………………………………167 7.7.5 Bonding at other than service equipment …………………………………….. 167 7.7.6 Loosely jointed metal raceways …………………………………………….…167 7.7.7 Bonding jumpers …………………………………………………………….. 167 7.8 Earthing electrodes ……………………………………………………………….….168 7.8.1 General…………………………………………………………………….…. 168 7.8.2 Service pipe electrode………………………………………………………….168 7.8.3 Artificial earthing electrodes ………………………………………………….169 7.9 Earthing and bonding conductors …………………………………………….………171 7.9.1 General ………………………………………………………………………….171 7.9.2 Installation of system earthing conductors ……………………………………….172 7.9.3 Installation of equipment bonding conductors …………………………………….173 7.9.4 Earthing conductor size for d.c. circuits ………………………………………….174 7.9.5 Earthing conductor size for a.c. system ………………………………………….174 7.9.6 Bonding conductor size ………………………………………………………….174 7.10 Earthing and bonding conductor connections ……………………………………..175 7.10.1 Bonding. conductor connection to raceways ………………………………175 7.10.2 Earthing conductor connection to water pipe electrodes ………………….175 7.10.3 Earthing conductor connections to other than water pipe electrodes ……….175 7.10.4 Bonding conductor connection to circuits and equipment …………………176 7.10.5 Earthing conductor cQJ111Cction to electrodes …………………………..176

SECTION 7 EARTHING, BONDING AND LIGHTNING PROTECTION PART II - LIGHTNING PROTECTION 7.11 Scope ……………………………………………………………………………….178 7.12 Normative references ……………………………………………………………….178

7.13 Definitions ………………………………………………………………………….179 7.14 Materials ………………………………………………………………………….180 7.14.1 General …………………………………………………………………….180 7.14.2 Galvanic compatibility ……………………………………………………….180 7.14.3 Corrosion protection ………………………………………………………….181 7.14.4 Mechanical protection ………………………………………………………….181 7.14.5 Use of aluminum ……………………………………………………………….181 7.15 Form and size ………………………………………………………………………….184 7.15.1 Air termination ……………………………………………………………….184 7.15.2 Conductors …………………………………………………………………….185 7.15.3 Earth termination ……………………………………………………………….185 7.15.4 Minimum dimension ………………………………………………………….185 7.16 Air termination ………………………………………………………………………….185 7.16.1 General ………………………………………………………………………….185 7.16.2 Support ………………………………………………………………………….185 7.16.3 Metallic projections …………………………………………………………….185 7.16.4 Metallic materials ……………………………………………………………….186 7.16.5 Structure within zone .of protection ………………………………………..…. 186 7.16.6 Air termination on roof ………………………………………………………….186 7.16.7 Air termination on reinforced concrete structure ……………………………….186 7.17 Down conductor ……………………………………………………………..………….186 7.17.1 General ………………………………………………………………….…….186 7.17.2 Routing ………………………………………………………………………. 187 7.17.3 Recommended number ………………………………………………………. 187 7.17.4 Mechanical protection ………………………………………………..……….187 7.17.5 Corrosive soil ………………………………………………………..…......... 187 7.17.6 External routes not available ………………………………………………….187 7.17.7 Lift shafts ……………………………………………………………….…….188 7.17.8 Re-entrant loops ……………………………………………………………….188 7.17.9 Sharp bends ………………………………………………………..………….188 7.17.10 Bonding to prevent side flashing …………………………………………….188 7.1 7.11 Bonds ………………………………………………………………..……. 188 7.17.12 Test points ……………………………………………………………..…….189

7.18 Earth termination .................... ……………………………………………………....... 190 7.18.1 Termination………………………………………………………….……….190 7.18.2 Resistance to earth …………………………………………………………….190 7.18.3 Earth electrodes……………………………………………………………….190 7.18.4 Connection point ……………………………………………………………….190 7.19 Common earthing ……………………………………………………………..……….192 7.19.1 Common earth potential ………………………………………………………. 192 7.19.2 Common earth bonding ……………………………………………………….. 192 7.20 Use of reinforcement for earthing in concrete Structures ………………………….193 7.20.1 General………………………………………………………………….…….193 7.20.2 Electrical continuity ………………………………………………………….193 7.20.3 Prestressed concrete members ………………………………………………….193 7.20.4 Precast concrete members …………………………………………………….193 7.21 Structural steel framing for lightning protection ……………………………………….194 7.21.1 General ……………………………………………………………..………….194 7.21.2 Air termination ………………………………………………………………. 194 7.21.3 Connection …………………………………………………………………….194 7.21.4 Earthing ……………………………………………………………………….194 7.21.5 Interconnection ……………………………………………………………….194 Annex (Informative) Annex A - System design ……………………………………………………………….219 Annex B - Consultation ……………………………………………………………….220

SECTION 8 WIRING METHODS 8.1 Scope ………………………………………………………………………………….223 8.2 Normative reference ………………………………………………………………….223 8.3 General requirements ………………………………………………………… …….223 8.3.1 Methods of installations ………………………………………………………….223 8.3.2 Wiring in ducts and plenum chambers ………………………………………….224 8.3.3 Underground installations …………………………………………………….224 8.3.4 Conductors in hoist ways ……………………………………………………….225

8.4 Conductors …………………………………………………………………………….226 8.4.1 Types of conductors ……………………………………………………………….226 8.4.2 Radii of bends in conductors ……………………………………………………….226 8.4.3 Conductor joints and splices ……………………………………………………….227 8.4.4 Supporting of conductors ………………………………………………………….228 8.5 Open wiring …………………………………………………………………………….228 8.5.1 Open and clipped direct ………………………………………………………….228 8.5.2 Spacing of conductors …………………………………………………………….228 8.5.3 Conductor supports ……………………………………………………………….229 8.5.4 Spacing of supports ……………………………………………………………….229 8.6 Exposed wiring on exterior of buildings and between Buildings on the same premises ...229 8.6.1 Location of conductors……………………………………………………………. 229 8.6.2 Clearance of conductors ………………………………………………………….229 8.6.3 Power supply conductors ………………………………………………………….229 8.7 Bare bus bars and risers ……………………………………………………………….230 8.8 Installation of boxes, cabinets, outlets and terminal fittings …………………………….230 8.8.1 Number of outlets per circuit …………………………………………………….230 8.8.2 Outlet boxes ……………………………………………………………………..231 8.8.3 Conductors in boxes ………………………………………………………….231 8.8.4 Terminal fittings ……………………………………………………………….231 8.9 Cables, conductors and wiring methods ……………………………………………….232 Annex A (Normative): Schedule of methods of installation of cables ………………….233

SECTION 9 PROTECTION AND CONTROL 9.1 Scope …………………………………………………………………………..…….237 9.2 Normative references ……………………………………………………………….237 9.3 General requirements ……………………………………………………………….237 9.3.1 Protective and control devices ……………………………………………….237 9.3.2 Types and ratings of protective and control devices ………………………….238 9.4 Protective devices ……………………………………………………………..……….238

9.4.1 Over current devices ………………………………………………………….238 9.4.2 Earth fault protection …………………………………………………………….239 9.5 Fuses ………………………………………………………………………………….240 9.6 Circuit breakers …………………………………………………………..………….240 9.7 Control devices ………………………………………………………..…………….240 9.8 Switches …………………………………………………………………….……….241 9.9 Protection and control of miscellaneous apparatus …………………………………….241

SECTION 10 CLASS 1 AND CLASS 2 CIRCUITS 10.1 Scope …………………………………………………………………………..…….245 10.2 Normative references ……………………………………………………………….245 10.3 Classification ………………………………………………………..……………….245 10.3.1 General ……………………………………………………………………….245 10.3.2 Class 1 extra-low-voltage power circuits …………………………………….246 10.3.3 Class 2 low-energy power circuits ………………………………………….246 10.3.4 Hazardous location …………………………………………………………….246 10.3.5 Circuits to safety control devices …………………………………………….246 10.3.6 Circuits in communication cables ……………………………………………. 246 10.4 Class 1 circuits ……………………………………………………………………….247 10.4.1 Limitation of Class 1 circuits ………………………………………………….247 10.4.2 Methods of installation for Class 1 circuits …………………………..……….247 10.4.3 Overcurrent protection of Class 1 circuits ……………………………..……..247 10.4.4 Location of overcurrent devices in Class 1 circuits ………………………….. 247 10.4.5 Class I extra-low-voltage power circuit sources including Transformers …... 248 10.4.6 Conductor material and sizes ………………………………………………….248 10.4.7 Insulated conductors for Class 1 wiring ………………………………….…..248 10.4.8 Conductors of different circuits in the ,same enclosure, cable, or Raceway ….248 10.4.9 Mechanical protection of remote-control circuits …………………………….249 10.4.10 Class 1 circuits extending aerially beyond a building ………………….…..249 10.5 Class 2 circuits …………………………………………………………………..…. 249 10.5.1 Limitations of Class 2 circuits ………………………………………………249 10.5.2 Methods of installation on supply side of overcurrent protection or Transformers or other devices for Class 2 circuits …………………….250

10.5.3 Marking ……………………………………………………………….…….250 10.5.4 Overcurrent protection for Class 2 circuits …………………………………250 10.5.5 Location of over current devices …………………………………………… 251 10.5.6 Conductors for Class 2 circuit wiring ………………………………………..251 10.5.7 Separation of Class 2 circuit conductors from other circuits ………………..251 10.5.8 Conductors of different Class 2 circuits in the same cable, enclosure, or raceway …………………………………………………………………...252 10.5.9 Penetration of a fire separation …………………………………………………252 10.5.10 Conductors in vertical shafts and hoistways ………………………………… 252 10.5.11 Class 2 conductors and equipment in ducts and plenum chambers ……….... 252 10.5.12 Equipment located on the load side of overcurrent protection, transformers, or current-limiting devices for Class 2 circuits ……………… 252 10.5.13 Class 2 circuits extending beyond a building ……………………………..253 10.5.14 Underground installations ………………………………………………… 253

SECTION 11 INSTALLATION OF ELECTRICAL EQUIPMENT 11.1 Scope ……………………………………………………………………………..….254 11.2 Normative references ……………………………………………………………….254 11.3 General ……………………………………………………………………………….254 11.3.1 Fusible equipment …………………………………………………………….254 11.3.2 Connection to identified terminals or leads …………………………………….254 11.3.3 Equipment over combustible surfaces ………………………………………….255 11.3.4 Installation of ventilated enclosures …………………………………………….255 11.3.5 Outdoor installations …………………………………………………..………255 11.4 Electric heating and cooking appliances ……………………………………………….255 11.4.1 Location of non-portable appliances ………………………………………….255 11.4.2 Rating of portable appliances ……………………………………….………….255 11.4.3 Appliance exceeding 1500 W …………………………………………………. 256 11.5 Heating equipment …………………………………………………………….………. 256 11.6 Submersible pumps …………………………………………………..……………….256 11.7 Motors and associated circuits ……………………………………………………….257 11.7.1 Wiring methods and conductors ……………………………………………….257 11.7.2 Overcurrent protection ……………………………………………………….260 11.7.3 Overload and overheating protection ………………………………………….262 11.7.4 Under voltage protection ………………………………………………………. 265

11.7.5 Control ………………………………………………………………………….266 11.7.6 Disconnecting means ………………………………………………………….267 11.8 Air conditioning and refrigerating equipment ………………………………………….268 11.8.1 General …………………………………………………………………..…….268 11.8.2 Branch circuit ………………………………………………………………….268 11.8.3 Disconnecting means ………………………………………………………….269 11.8.4 Supply cords ………………………………………………………………. 269 11.9 Storage batteries ……………………………………………………………..……….269 11.9.1 Location of storage batteries ………………………………………………….269 11.9.2 Ventilation of battery rooms or areas ………………………………………….269 11.9.3 Battery vents …………………………………………………………………….269 11.9.4 Battery installation……………………………………………………………….269 11.9.5 Wiring …………………………………………………………….…………….270

SECTION 12 HAZARDOUS LOCATIONS 12.1 Scope …………………………………………………………………..….………….279 12.2 Nonnative reference …………………………………………………….…………….279 12.3 Classification ……………………………………………………………….………….279 12.3.1 Division of Class I locations …………………………………………………. 279 12.3.2 Division of Class II locations ………………………………………………….280 12.3.3 Division of Class III locations ………………………………………………….281 12.4 General requirements ……………………………………………………………….281 12.4.1 Electrical equipment ………………………………………………………….281 12.4.2 Marking ……………………………………………………………….……….282 12.4.3 Non-essential electrical equipment …………………………………………….283 12.4.4 Equipment rooms ………………………………………………………………. 283 12.4.5 Cable trays …………………………………………………..…………………. 284 12.5 Class I locations …………………………………………………………………..…….284 12.5.1 Installations in Class I, Division 1 locations ……………………………………284 12.5.2 Installations in Class I, Division 2 locations …………………………………..286 12.6 Class II locations …………………………………………………………………..….287

12.6.1 Installations in Class II, Division 1 locations ……………………….………..287 12.6.2 Installation in Class II, Division 2 locations ………………………..………. 289 12.7 Class III locations …………………………………………………………….……….290 12.7.1 Installations in Class III, Division 1 locations ………………………………..290 12.7.2 Installations in Class III, Division 2 locations ……………………….……….293

SECTION 13 FLAMMABLE LIQUID DISPENSING AND SERVICE STATIONS, GARAGES, BULK STORAGE PLANTS, FINISHING PROCESSES AND AIRCRAFT HANGARS 13.1 Scope ……………………………………………………………………………….294 13.2 Nonnative references ……………………………………………………………….295 13.3 Gasoline dispensing and service stations ………………………………………….295 13.3.1 Hazardous areas …………………………………………………………….295 13.3.2 Wiring and equipment within hazardous areas ……………………………..296 13.3.3 Wiring and equipment above hazardous areas ……………………………..297 13.4 Commercial garages, repairs and storage ……………………………………………297 13.4.1 Hazardous areas ……………………………………………………………….297 13.4.2 Wiring and equipment in hazardous areas ……………………………………298 13.4.3 Wiring above hazardous areas ……………………………………………..298 13.4.4 Equipment above hazardous areas …………………………………………..298 13.5 Residential storage garages 298 13.5.1 Non-hazardous location………………………………………………………298 13.5.2 Hazardous location …………………………………………………………….299 13.5.3 Wiring ……………………………………………………………………..…. 299 13.6 Bulk storage plants ………………………………………………………..………. 299 13.6.1 Hazardous areas ……………………………………………………………….299 13.6.2 Wiring and equipment in hazardous areas …………………………………..302 13.6.3 Wiring and equipment above hazardous areas ……………………………….302 13.7 Finishing processes ………………………………………………………………….302

13.7.1 Hazardous locations …………………………………………………………302 13.7.2 Wiring and equipment in hazardous areas ………………………………….304 13.7.3 Wiring and equipment above hazardous areas …………………………… 305 13.8 Aircraft hangars ……………………………………………………………………… 305 13.8.1 Hazardous areas……………………………………………………………….305 13.8.2 Wiring and equipment in hazardous areas ………………………………… 306 13.8.3 Wiring not within hazardous area…………………………………………… 306 13.8.4 Equipment not within hazardous areas ……………………………..………. 307

SECTION 14 PATIENT CARE AREAS 14.1 Scope………………………………………………………………………………..308 14.2 Nonnative references ……………………………………………………………….308 14.3 Definitions …………………………………..………………………………….…….308 14.4 Circuits in basic care areas …………………………………………………………….311 14.4.1 Branch circuits ……………………………………………………………….311 14.4.2 Bonding to earth in basic-care areas …………………………………………….311 14.4.3 Socket outlets in basic-care areas ……………………………………………….312 14.5 Circuits in intermediate and critical-care areas ……………………………………….313 14.5.1 Branch circuits ……………………………………………………………….313 14.5.2 Bonding to earth in intermediate and critical-care areas ……………………. 313 14.5.3 Receptacles in intermediate-and critical-care areas …………………………….313 14.6 Isolated systems …………………………………………………………………….…. 314 14.6.1 Sources of supply ……………………………………………………………… 314 14.6.2 Single-phase isolated circuits …………………………………………………. 314 14.6.3 Three-phase isolated systems ………………………………………………….315 14.7 Essential electrical systems …………………………………………………………….315 14.7.1 Circuits in essential electrical systems ………………………………………….315 14.8 Transfer switches ………………………………………………………………………. 316 14.9 Emergency supply ………………………………………………………………...…….316

SECTION 15 INSTALLATION OF LIGHTING EQUIPMENT

15.1 Scope ……………………………………………………….……………………..…. 3 18 15.2 Normative references ………………………………………………………………….318 15.3 Interior lighting equipment …………………………………………………………….318 15.3.1 General ………………………………………………………………………. 318 15.3.2 Location of lighting equipment ……………………………………………….320 15.3.3 Installation of lighting equipment …………………………………………….323 15.3.4 Wiring of lighting equipment ………………………………………………….323 15.3.5 Earthing of-lighting equipment ……………………………………………….326 15.3.6 Electric-discharge lighting systems operating at 1000V or less ……………..326 15.4 Outdoor lighting equipment ………………………………………………………….327 15.4.1 General………………………………………………………..……………….327 15.4.2 Permanent outdoor floodlighting installation ……………….………………..328 15.4.3 Exposed wiring for permanent outdoor lighting ………….……………….…331 Annex A (Normative) …………………………………….…………………………….….334

SECTION 16 FIRE ALARM SYSTEM AND FIRE. PUMPS 16.1 Scope ……………………………………………………………………………….344 16.2 Normative references …………………….………………………………………….344 16.3 Definitions ………………………………………………..……………………..….344 16.4 Design consideration ……………………………………………………………….346 16.4.1 General ………………………………………………………………….….346 16.4.2 Circuit design ……………………………………………………………….347 16.4.3 Manual call points ………………………………………………………….348 16.4.4 Selection of fire detectors ………………………………………………….349 16.4.5 Sitting of detectors ………………………………………………………….350 16.4.6 Sitting of heat sensitive (point) detectors……………………………………….350 16.4.7 Vibration combined with rapid temperature change ………………………….. 353 16.4.8 Sitting of heat-sensitive (line) detectors……………………………………….354 16.4.9 Sitting of smoke-sensitive detectors …………………………………………….354 16.4.10 Audible and visual alarms ………………………………………………….354 16.5 Cables and wiring …………………………………………………………………….356 16.5.1 Cables………………………………………………………………………..356

16.5.2 Wiring method ……………………………………………………………….357 16.6 Equipment bonding …………………………………………………………………….359 16.6.1 Exposed non-current carrying metal part……………………………………….359 16.6.2 Bonding conductor ……………………………………………………….…….359 16.7 Power supply system ……………………………………………………………….….359 16.7.1 Operating voltage……………………………………………………………….359 16.7.2 Sources of power ……………………………………………………………….359 16.7.3 Current supply ……………………………………………………………….360 16.8 Fire pumps …………………………………………………………………………...361 16.8.1 Conductors ……………………………………………………………….….361 16.8.2 Wiring method ……………………………………………………………….361 16.8.3 Consumers’ service for fire pumps …………………………………………….361 16.8.4 Protection ………………………………………………………………..…….362 Annex A (Informative) ……………………………………………………………….…….363 Annex B (Informative) …………………………………………………………………….365

SECTION 17 SIGNS AND OUTLINE LIGHTING 17.1 Scope………………………………………………………………………………….371 17.2 Normative references ……………………………………………………………….371 17.3 General requirements ……………………………………………………………….371 17.3.1 Construction ……………………………………………………………….371 17.3.2 Disconnecting means ………………………………………………………….372 17.3.3 Rating of disconnecting means and control devices …………………………..372 17.3.4 Thermal protection…………………………………………………………….372 17.3.5 Branch. circuit capacity ……………………………………………………….372 17.3.6 Location ……………………………………………………………………..….372 17.3.7 Bonding ……………………………………………………………………..….373 17.3.8 Protection of sign leads …………………………………………………..…….373 17.3.9 Installation of conductors ……………………………………………………….373 17.3.10 Fuse holders and flashers …………………………………………………….373 17.4 High-voltage luminous discharge tube signs and outline Lighting …………………..373

17.4.1 Enclosure …………………………………………………………………..….373 17.4.2 Protection of uninsulated part ………………………………………………….374 17.4.3 Transformers ……………………………………………………………..…….374 17.4.4 High-voltage wiring methods ………………………………………………….375

SECTION 18 LIFTS, ESCALATORS AND SIMILAR EQUIPMENT 18.1 Scope ……………………………………………………………………………….377 18.2 Normative references ……………………………………………………………….377 18.3 General ……………………………………………………………………..……….377 18.3.1 Voltage limitation …………………………………………………………. 377 18.3.2 Live parts enclosed…………………………………………………………….377 18.4 Conductors ……………………………………………………………………….…….378 18.4.1 Installation of conductors ……………………………………………………….378 18.4.2 Minimum size of conductors ………………………………………………….378 18.4.3 Motor circuit conductors …………………………………………………….379 18.5 Wiring …………………………………………………………………….………….379 18.5.1 Wiring methods ……………………………………………………………….379 18.5.2 Branch circuits for auxiliary systems ………………………………………….380 18.6 Installation of conductors ……………………………………………………………….380 18.6.1 Number of conductors in raceway …………………………………...………….380 18.6.2 Supports …………………………………………………………………..…….380 18.6.3 Different systems in one raceway or travelling cable …………………………. 380 18.6.4 Wiring in hoistway …………………………………………………..………….381 18.6.5 Electric equipment in garages and similar occupancies ……………………….381 18.6.6 Sidewalk lifts ……………………………………………………………….381 18.7 Traveling cables …………………………………………………………………..….381 18.7.1 Suspension ………………………………………………………………..….381 18.7.2 Hazardous (classified) location ……………………………………………….382 18.7.3 Protection against damage …………………………………………………….382 18.7.4 Installation …………………………………………………………………….382 18.8 Disconnecting means and control ……………………………………………………….382

18.8.1 General …………………………………………………………………..…….382 18.8.2 Type ……………………………………………………………………..…….383 18.8.3 Location……………………………………………………………………….383 18.8.4 Phase protection……………………………………………………………….383 18.9 Overcurrent protection ……………………………………………………………….383 18.9.1 Control and operating circuits ………………………………………………….383 18.9.2 Motors ………………………………………………………………………….384 18.10 Machine room ……………………………………………………………….……….384 18.10.1 Guarding equipment ………………………………………………………….384 18.10.2 Clearance around control panels and disconnecting means ………………….384 18.11 Earthing…………………………………………………………………………..….384 18.11.1 Metal raceway attached to cars …………………………………………….384 18.11.2 Electric lifts ……………………………………………………………….385 18.11.3 Non-electric lifts …………………………………………………………….385 18.11.4 Method of bonding ………………………………………………………….385 18.12 Overspeed …………………………………………………………………..……….385 18.12.1 Overspeed protection ……………………………………………………….385 18.12.2 Motor-generator overspeed device ………………………………………….386 18.13 Emergency power ………………………………………………………….………….386 18.13.1 Supply ……………………………………………………………………….386 18.13.2 Disconnection ……………………………………………………………….386 18.13.3 Hydraulic lifts disconnecting means ………………………………………….386 18.14 Machine rooms and hoistway pits lighting and Auxiliary …………………………….386 18.14.1 Machine room ……………………………………………………………….386 18.14.2 Hoist pits …………………………………………………………………….387

SECTION 19 THEATRE INSTALLATION 19.1 Scope………………………………………………………………………………….388 19.2 Normative references ……………………………………………..………………….388 19.3 Wiring method …………………………………………………………….………….388

19.4 Fixed stage switchboard ……………………………………………………………….389 19.4.1 Fuses …………………………………………………………..…………….389 19.4.2 Overcurrent protection ………………………………………………………. 389 19.4.3 Dimmers …………………………………………………..……..…………….390 19.4-4 Control of stage and gallery pockets…………………………………………….390 19.4.5 Conductors ………………………………………………………….………….390 19.5 Portable switchboard on stage ………………………………………………………….391 19.5.1 Construction of portable switchboards ………………………………………….391 19.5.2 Supply for portable switchboard ……………………………………………….391 19.6 Fixed stage equipment ……………………………………………………………….391 19.6.1 Footlights ……………………………………………………………….…….391 19.6.2 Metal work …………………………………………………………..……….391 19.6.3 Clearance at terminals ……………………………………………………….392 19.6.4 Mechanical protection of lamps in borders, etc ……………………………….392 19.6.5 Suspended fixtures …………………………………………………………….392 19.6.6 Connections at lamp holders ………………………………………………….392 19.6.7 Ventilation for mogul lampholders…………………………………………….392 19.6.8 Conductor insulation for field-assembled fixtures …………………………….392 19.6.9 Branch circuit overcurrenf protection ……………………………………….392 19.6.10 Pendant lights rated more than l00 W ……………………………………….393 19.6.11 Cables for border lights ………………………………………………….….393 19.6.12 Wiring to arc pockets ……………………………………………………….393 19.6.13 Socket outlets and plugs …………………………………………………….393 19.6.14 Curtain motors ……………………………………………………………….394 19.6.15 Flue damper control ………………………………………………………….394 19.7 Portable stage equipment …………………………………………………………….394 19.7.1 Fixtures on scenery …………………………………………………………….394 19.7.2 String or festooned lights ……………………………………………………….395 19.7.3 Flexible conductors from portable equipment ………………………………….395 19.7.4 Portable equipment for stage effects ……………………………………...…….395

SECTION 20 EMERGENCY SYSTEMS, UNIT EQUIPMENT, AND EXIT SIGNS

20.1 Scope …………………………………………………………………………………396 20.2 Normative reference ……………………………………………………….………….396 20.3 General ………………………………………………………………………….…….396 20.3.1 Adequate capacity …………………………………………………………….396 20.3.2 Instruction ……………………………………………………………….397 20.3.3 Batteries maintenance ………………………………………………………….397 20.3.4 Lamps ………………………………………………………………………….397 20.3.5 Circuits ……………………………………………………………..………….397 20.3.6 Method of wiring ……………………………………………………………….397 20.4 Emergency systems …………………………………………………………………….398 20.4.1 Supply ………………………………………………………………..……….398 20.4.2 Control ……………………………………………………………….……….398 20.4.3 Overcurrent protection ………………………………………………………….398 20.4.4 Audible and visual trouble-signal devices …………………………………….398 20.5 Unit equipment ……………………………………………………………………….399 20.5.1 Mounting ……………………………………………………………………….399 20.5.2 Supply connections …………………………………………………………….400 20.6 Exit signs ………………………………………………………………………..…….401 20.6.1 Power supply ………………………………………………….……………….401 20.6.2 Wiring ………………………………………………………………………….401

SECTION 21 MOTION PICTURE STUDIOS, PROJECTION ROOMS, FILM EXCHANGES AND FACTORY 21.1 Scope ………………………………………………………………………………….402 21.2 Normative references ………………………………………………………………….402 21.3 General …………………………………………………………………………….….402 21.3.1 Wiring method ……………………………………………………………….402 21.4 Viewing, cutting and patching table fixture …………………………………………….403 21.5 Film-vaults and storage rooms ………………………………………………………….403 21.5.1 Equipment in film vaults and storage rooms ………………………………….403 21.5.2 Wiring method in film-vaults ………………………………………………….403 21.5.3 Lighting fixtures in film-vaults ……………………………………………….403

21.5.4 Film-vault circuits ……………………………………………………….…….404 21.6 Motion picture projection rooms …………………………………………..………….404 21.6.1 Lamps in projection rooms …………………………………………………….404 21.6.2 Arc lamp current supply ……………………………………………………….404 21.6.3 Ventilation ………………………………………………………………….….404 21.7 Motors and generators ……………………………………………………………..….404

SECTION 22 DIAGNOSTIC IMAGING INSTALLATION 22.1 Scope ……………………………………………………………………………..….405 22.2 Nonnative references ……………………………………………………………….405 22.3 Definitions …………………………………………………………………..……….405 22.4 High-voltage guarding ……………………………………………………………….406 22.5 Connections to supply circuit ………………………………………………………….406 22.6 Disconnecting means ………………………………………………………………….406 22.7 Transformers and capacitors …………………………………………………………….407 22.8 Control ………………………………………………………………………………….407 22.9 Ampacity of supply conductors and rating of overcurrent protection ………………….408 22.10 Bonding ……………………………………………………………………………….408

SECTION 23 ELECTRICAL COMMUNICATION SYSTEMS 23.1 Scope ………………………………………………………………………..………. 409 23.2 Nonnative reference ………………………………………………………………….409 23.3 General ………………………………………………………………………..……….409 23.3.1 Circuits in communication cables ……………………………………………….409 23.3.2 Hazardous locations ……………………………………………….…………….410 23.3.3 Approved transformers ………………………………………….……………….410 23.4 Inside conductors ……………………………………………………………………….410 23.4.1 Conductors arrangement ……………………………………………………….410 23.4.2 Insulation ……………………………………………………………..……….410 23.4.3 Earthing conductors with an outer metal covering ……………………………..410 23.4.4 Separation from other conductors ……………………………………..………410 23.4.5 Penetration of a fire separation …………………………………………………411

23.4.6 Communication cable in hoistways …………………………………………….411 23.4.7 Communication conductors in ducts and plenum chambers ……………….….412 23.4.8 Data processing systems ……………………………………………………….412 23.4.9 Conductors under raised floors ………………………………………………….412 23.4.10 Conductors in concealed installations ……………………………………….412 23.4.11 Type CFC under-carpet wiring system ……………………………………….413 23.5 Equipment ………………………………………………………………………….….414 23.5.1 Communication equipment in bathrooms …………………………….……….414 23.5.2 Equipment in air ducts, plenums, or suspended ceilings ……………………….414 23.5.3 Exposed equipment and terminations …………………………………………. 415 23.5.4 Earth circuits ……………………………………………..…………………….415 23.5.5 Communication systems in hospitals ………………………………………….415 23.6 Outside conductors ………………………………………………………..…………….415 23.6.1 Overhead conductors on poles ………………………………………………….415 23.6.2 Overhead conductor$ on roofs ………………………………………………….415 23.6.3 Lightning conductors ………………………………………………………….416 23.6.4 Swimming pools ……………………………………………………………….416 23.7 Underground circuits………………………………………………………………….416 23.7.1 Direct buried systems …………………………………………….………….416 23.7.2 Underground raceway ……………………………………………………….417 23.8 Earthing 417 23.8.1 Bonding of cable sheath ……………………………………………….……….417 23.8.2 Cable-sheath bonding conductor ……………………………………………….418 23.8.3 Earthing electrode ……………………………………………………………….418 23.8.4 Earthing electrode connection ………………………………………………….419 23.8.5 Bonding of electrodes …………………………………………………….…….419

SECTION 24 COMMUNITY ANTENNA INSTALLATION FOR RADIO AND TELEVISION RECEPTION 24.1 Scope ……………………………………………………………………………..….420. 24.2 Normative references…………………………………………………..…………….420 24.3 Technical requirements……………………………………………………………….421

24.3.1 Mechanical ………………………………………………………………. 421 24.3.2 Electrical ………………………………………………………….……….421 24.4 Equipment ………………………………………………………………………….….421 24.4.1 Community antenna distribution amplifiers and other power sources…………..421 24.4.2 Exposed equipment and terminations …………………………………………..422 24.4.3 Equipment earthing ….………………………………………………………….422 24.5 Community antenna distribution network …………………………………………….422 24.5.1 Conductor ……………………………………………………………….…….422 24.5.2 Voltage limitation ……………………………………………………………….422 24.5.3 Hazardous locations …………………………………………………….…….423 24.5.4 Supports ……………………………………………………………………….423 24.5.5 Earthing of outer conductive shield of a coaxial cable ……………………….423 24.5.6 Earthing conductor …………………………………………………………….423 24.5.7 Earthing electrode …………………………………………………………….424 24.5.8 Earthing electrode connection ……………………………………………….424 24.6 Conductors within buildings ………………………………………………………….424 24.6.1 Separation from other conductors …………………………………………….424 24.6.2 Conductors in a vertical shaft ……………………………………………….425 24.6.3 Penetration of a fire separation ……………………………………………….426 24.6.4 Community antenna distribution conductors in ducts and plenum Cambers ... 426 24.6.5 Raceways …………………………………………………………………..….426 24.7 Conductors outside of buildings ……………………………………………………….426 24.7.1 Overhead conductors on poles………………………………………………….426 . 24.7.2 Overhead conductors on roofs ……………………………………………..….426 24.7.3 Conductors on buildings………………………………………………….…….426 24.7.4 Conductors entering buildings ………………………………………………….427 24.7.5 Swimming pools ……………………………………………………………….427 24.8 Underground conductors ……………………………………………………………….427 24.8.1 Direct buried systems ……………………………….………………………….427 24.8.2 Underground raceway………………………………………………………….428 24.8.3 Underground block distribution ………………………………….…………….429

24.9 Lightning arresters for receiving stations ……………………………………………….429 24.9.1 Lightning arrester …………………………………………………………….429 24.9.2 Earthing conductor ……………………………………..…………………….429 24.9.3 Earthing electrode …………………………………………………………….430 Annex A (Informative) …………………………………………..………………………….431

SECTION 25: SWIMMING POOLS, FOUNTAINS AND SIMILAR INSTALLATIONS 25.1 Scope …………………………………………………………….…………………. 446 25.2 Normative reference ………………………………………………………………….446 25.3 Definitions …………………………………………………………..……………….446 25.4 General …………………………………………………………….………………….447 25.4.1 Equipment installation ………………………………………………………….447 25.4.2 Overhead wiring ……………………………………………………………….448 25.4.3 Underground wiring ………………………………………………………….448 25.4.4 Bonding to earth ……………………………………………………………….449 25.4.5 Junction and deck boxes ……………………………………………………….450 25.4.6 Transformers and transformer enclosure ……………………………………….451 25.4.7 Socket outlets ……………………………………………….………………….452 25.4.8 Luminaries and lighting equipment …………………….……………………….452 25.4.9 Earth-fault circuit breakers ……………………………………………………….454 25.5 Permanently installed swimming pools ……………………………………………….455 25.5.1 General ……………………………………………………………………….455 25.5.2 Conduit type ………………………………………………………………….455 25.5.3 Circuit segregation ……………………………………….………………….455 25.5.4 Drainage ………………………………………………….……..…………….455 25.6 Storable swimming pools ……………………………………………………………….455 25.6.1 Electrical equipment …………………………………..……………………….455 25.6.2 Pumps ………………………………………………………………………….456 25.7 Hydromassage bathtub ……………………………………………………………….456 25.7.1 Protection …………………………………………………………………….456 25.7.2 Control ……………………………………………………….……………….456

25.7.3 Other electric equipment …………………………………….……………….457 25.8 Spas and hot tubs ……………………………………………………..……………….457 25.8.1 Bonding to earth ……………………………………………………………….457 25.8.2 Controls and other electrical equipment ……………………………………….457 25.8.3 Leakage current ……………………………………………………………….458 25.8.4 Field-assembled units ………………………………………..……………….458 Annex A (Informative) ………………………………………………………….………….460

SECTION 26: SOLAR PHOTOVOLTAIC SYSTEM 26.1 Scope 26.2 Normative References 26.3 Special Terminology 26.4 Marking 26.5 maximum Photovoltaic Source Circuit and Output Circuit Voltage 26.6 Voltage drop 26.7 Ampere Rating of Photovoltaic Source Circuits 26.8 Overcurrent Protection for Apparatus and Conductors 26.9 Photovoltaic dc arc-fault circuit protection 26.10 Disconnecting means 26.11 Wiring Method 26.12 Attachment plugs and similar wiring devices 26.13 Module Connection Arrangement 26.14 Interconnected System Connection 26.15 Solar photovoltaic systems earthing 26.16 Power conditioning unit

SECTION 27: RENEWABLE ENERGY SYSTEMS 27.1 Scope 27.2 Normative References 27.3 Special Terminology 27.4 General 27.5 Overcurrent Protection 27.6 Disconnecting Means

27.7 Wiring method 27.8 System Earthing 27.9 Ungrounded Renewable Energy Power Systems 27.10 Earthing Electrodes and Earthing conductors 27.11 Equipment bonding 27.11 Marking 27.12 Warning notice and diagram 27.13 Interconnections to other Circuits 27.14 Interconnected system connection 27.15 Loss of interactive system power 27.16 Systems in excess of 750 V dc 12.17 INVERTERS 27.17.1 Maximum circuit loading 27.17.2 Stand-alone systems 27.17.3Utility-interactive inverters mounted in locations that are not readily accessible 27.17.4 Connection to other sources 27.17.5 Ampacity of neutral conductor 27.17.6 Unbalanced interconnections 27.17.7 Utility-interactive point of connection 27.18 STATIONARY FUEL CELL SYSTEMS 27.18.1 Marking 27.18.2 Conductors 27.18.3 Overcurrent protection 27.18.4 Disconnecting means 27.18.5 Wiring methods 27.18.6 Grounding and bonding 27.18.7 Location of Fuel Cells 27.18.8 Outdoor installations 27.18.9 Indoor installations 27.18.10 Electrical equipment 27.19 SMALL WIND SYSTEMS 27.19.1 Marking 27.19.2 Maximum voltage 27.19.3 Conductors

27.19.4 Wiring methods 27.19.5 Overcurrent protection for apparatus and conductors 27.19.6 Disconnecting means 27.19.7 Grounding and bonding 27.19.8 Lightning protection systems 27.19.9 Diversion load controllers 27.19.10 Surge protective devices 27.19.11 Installation and service of a wind turbine 27.20 LARGE WIND SYSTEMS 27.20.1 Marking 27.20.2 Conductors 27.20.3 Overcurrent protection for apparatus and conductors 27.20.4 Disconnecting means 27.20.5 Grounding and bonding 27.20.6 Lightning protection systems 27.20.7 System demarcation point 27.21 MICRO-HYDROPOWER SYSTEMS 27.21.1 Marking 27.21.2 Conductors 27.21.3 Wiring methods 27.21.4 Overcurrent protection for apparatus and conductors 27.21.5 Disconnecting means 27.21.6 Stand-alone systems 27.21.7 Grounding and bonding 27.22 HYDROKINETIC POWER SYSTEMS 27.22.1 Marking 27.22.2 Conductors 27.22.3 Stand-alone systems 27.22.4 Overcurrent protection for apparatus and conductors 27.22.5 Wiring methods 27.22.6 Disconnecting means 27.22.7 Grounding and bonding

27.23 STORAGE BATTERIES 27.23.1 Installation 27.23.2 Current limiting 27.23.3 Battery non-conductive cases and conductive racks 27.23.4 Disconnection of series battery circuits 27.23.5 Battery systems of more than 48 V 27.23.6 Battery interconnections 27.23.7 Charge control 27.23.8 Diversion charge controller

SECTION 28: GRAPHICAL SYMBOLS 28.1 Scope ……………………………………………………………………………….462 28.2 Normative references ……………………………………………………………….462 28.3 Definitions ··········· ……………………………………………………………….462 28.4 Symbols ……………………………………………………………….………….463 Annex A - (Informative) ……………………………………………………………….470 Annex B - (Informative) ……………………………………………………………….471

Appendices Appendix I Inspection and testing ……………………………………………………………….A-1 Appendix 2 Forms of completion and inspection certificate ……………………………………….A-9