GENERAL SPECIFICATION FOR ELECTRICAL INSTALLATION …

1 GENERAL SPECIFICATION FOR ELECTRICAL INSTALLATION IN GOVERNMENT BUILDINGS OF THE HONG KONG SPECIAL ADMINISTRATIVE REGION 2017 EDITION ARCHITECTURAL SERVICES DEPARTMENT THE GOVERNMENT OF THE HONG KONG SPECIAL ADMINISTRATIVE REGION PREFACE This GENERAL SPECIFICATION aims to lay down the technical requirements of materials and equipment, the standards of workmanship, the requirements on testing and commissioning, and operation and maintenance as well as requirements on document submissions for ELECTRICAL INSTALLATION in Government Buildings of the Hong Kong Special Administrative Region (HKSAR). The 2017 edition of this GENERAL SPECIFICATION was developed from the 2012 edition (incorporating Corrigendum No.)

2 GSEE02-2012) by the ELECTRICAL Specialist Support Group that was established under the Building Services Branch Technical Information and Research & Development Committee of the Architectural Services Department (ArchSD). It incorporates updated international standards and codes as well as technological developments which find applications in Hong Kong. To be in line with the Department s endeavour to reduce the environmental burden on our neighbours and to help preserving common resources while improving the quality of our service, this GENERAL SPECIFICATION puts emphasis on green features and green practices for construction as well as initiatives for enhancement of client satisfaction on completed projects.

3 With the benefit of information technology, electronic version of this edition is to be viewed on and free for download from the ArchSD Internet homepage. As part of the Government s efforts to limit paper consumption, hard copies of this GENERAL SPECIFICATION will not be put up for sale. The draft of the 2017 edition has been circulated to stakeholders within and external to the Government before finalisation. Nevertheless, the ArchSD welcomes comments on its contents at any time since the updating of this GENERAL SPECIFICATION is a continuous process for the inclusion of any developments that can help meeting the needs of our community. DISCLAIMER This GENERAL SPECIFICATION is solely compiled for ELECTRICAL INSTALLATION carried out for or on behalf of the ArchSD in Government buildings of the HKSAR.

4 There are no representations, either expressed or implied, as to the suitability of this GENERAL SPECIFICATION for purposes other than that stated above. Users who choose to adopt this GENERAL SPECIFICATION for their works are responsible for making their own assessments and judgement of all information contained here. The ArchSD does not accept any liability and responsibility for any special, indirect or consequential loss or damages whatsoever arising out of or in connection with the use of this GENERAL SPECIFICATION or reliance placed on it. The materials contained in this document may not be pertinent or fully cover the extent of the INSTALLATION in non-government buildings and there is no intimated or implied endorsement of the sales, supply and INSTALLATION of the materials and equipment specified in this GENERAL SPECIFICATION within the territory of the HKSAR.

5 Table of Contents Page 1 of 29 EE_GS 2017 Edition TABLE OF CONTENTS PART A SCOPE AND GENERAL REQUIREMENTS SECTION A1 SCOPE OF SPECIFICATION Installations to Comply with this GENERAL SPECIFICATION Scope of the Installations Terms and Definitions Singular and Plural SECTION A2 STATUTORY OBLIGATIONS AND OTHER REGULATIONS Statutory Obligations and Other Requirements Statutory Obligations Other Requirements Safety Requirements Technical Standards Case of Conflict SECTION A3 EXECUTION OF INSTALLATIONS The International System of Units (SI) Programme of Installations Builder s Work Coordination of Installations Cooperation with Other Contractors Site Supervision Sample Board Advice of Order Placed Record of Materials Delivery Protection of Materials and Equipment Painting SECTION A4 DRAWINGS AND MANUALS Drawings in Electronic Format INSTALLATION Drawings Drawing Submission Schedule Size of INSTALLATION Drawings Contents of INSTALLATION Drawings Builder s Work Drawings Manufacturer s Shop Drawings Table of Contents Page 2 of 29 EE_GS 2017 Edition Checking Drawings of Other Trades As-built Drawings Submission of As-built Drawings Size of As-built Drawings Content of As-built

6 Drawings Framed Drawings Operation and Maintenance (O&M) Manual and User Manual GENERAL Presentation Checking and Approval Structure and Contents of O&M Manual Structure and Contents of User Manual Intellectual Property Rights Table of Contents Page 3 of 29 EE_GS 2017 Edition PART B INSTALLATION METHODOLOGY SECTION B1 GENERAL Workmanship Tradesmen Tool and Instrument Safety on Site Label and Notice Inscription of Label and Engraving Material for Label Fixing of Label Engraving for ELECTRICAL Accessory Warning Notice Other Labels and Notices Guard and Railing for Moving or Rotating Parts of Equipment Identification of Cable and Conduit Fixing to Wooden Plug Painting of Metal Work Water Proofing

7 Provision of Spare Fuses in Main Switch Room SECTION B2 INSTALLATION OF WIRING SYSTEMS Wiring in Steel Conduit System Type of Cable Concealed Steel Conduit System Surface Conduit System Minimum Size of Conduit Flexible Conduit Conduit Continuity Joint in Conduits Provision of Adaptable Box Spacing between Conduits Termination of Conduits at Metal Casing of Equipment Conduit Bend Conduit Crossing Expansion Joint Use of Extension Piece Prevention of Ingress of Foreign Matters Prevention of Accumulation of Water or Moisture Table of Contents Page 4 of 29 EE_GS 2017 Edition Conduit Laid Direct in Ground Fixing of Distance (Spacing) Saddle Conduit Installed Outdoors or in Damp Situation Swabbing Out of Conduit Fire Barrier Cable Capacity of Conduit Method of Drawing Cables into Conduit Segregation of Cables of Different Circuit Categories Looping-in Wiring System Grouping of Cables in Conduit Termination of Bonding Conductors at Conduit INSTALLATION Wiring in Steel Trunking System GENERAL Provision of Cable Retaining Bar and Cable Support Cable Capacity of Trunking Correction Factor of Grouping Segregation of Cables of Different Circuit Categories Connection to Equipment Connection to Distribution Board Fixing of Surface

8 Trunking Cables through Trunking Fire Barrier Prevention of Electrolytic Action Prevention of Ingress of Water Wiring in Plastic Conduit or Plastic Trunking System GENERAL Pliable Conduit Joint in PVC Conduit Plastic Boxes Termination of PVC Conduit at Casing of Equipment Conduit Bend Allowance for Thermal Expansion Fixing of Trunking Circuit Protective Conductor Embedment of Concealed PVC Conduits Table of Contents Page 5 of 29 EE_GS 2017 Edition Surface Wiring System Type of Cable Minimum Size of Live Conductors and CPC Identification of Cable Core Joint in Cable or Cord INSTALLATION of Non-flexible Cable INSTALLATION of Flexible Cable and Flexible Cord Tool and Workmanship Approved Tool Cutting in Metal Work for Conduit or in Trunking Making Good of Damaged Coating SECTION B3 INSTALLATION OF POWER CABLES.

9 CABLE TRAYS AND CABLE LADDERS GENERAL Scope Electromagnetic Interference Cable Mounted on Surface Cable Laid in Enclosed Trench Cable Enclosed in Duct GENERAL Drawing-in of Cables Internal Barrier Fire Barrier Draw-in Pit Segregation of Cables of Different Circuit Categories Sealing of Duct Entry to Building Cable Buried Direct in Ground Protection of Cable Cable Marker Bending Radius of Cable Cable Joint and Cable Termination GENERAL Joint Box and Terminating Box Identification at Joint or Termination Earth Continuity across Joint Straight-through Joint for Copper Conductors Tee-joint for Copper Conductor Joint for Aluminium Cables Table of Contents Page 6 of 29 EE_GS 2017 Edition Termination of PVC-insulated or XLPE-insulated Cable with Copper Conductors Termination of PVC-insulated or XLPE-insulated Cable with Aluminium Conductors Use of Heat Shrinkable Tubing Other Methods of Joint and Termination Special Requirements for Mineral Insulated Cables Cable Route Cable Support Bending Radius Cable Loop for Prevention of Vibration and Low Temperature Cold Store Cable Termination Insulation Resistance Bonding of Cable Sheath to Metalwork Laying of Single-core Cables Protection from Mechanical Damage INSTALLATION of Perforated Cable Trays Connection between

10 Adjacent Lengths of Tray Cutting of Tray Hole in Tray Fixing of Tray Fixing of Cable on Tray INSTALLATION of Wire Mesh Cable Trays GENERAL Supports Bends Earthing Safety Working Load INSTALLATION of Cable Ladder Dropout Plate for Cable Exit Flexible (Expansion) Couplers across Building Expansion Joint Ladder Covers End Connectors Earthing Minimum Inside Radius of All Bends Supports Safety Working Load Table of Contents Page 7 of 29 EE_GS 2017 Edition SECTION B4 INSTALLATION OF GENERAL LIGHTING AND POWER INSTALLATION of Lighting System and Luminaires Pendant Luminaire Mounted on Pattress Ceiling Rose Painting Special Requirements for Outdoor Luminaires INSTALLATION of Wiring Accessories INSTALLATION of Domestic Switches GENERAL Lighting Switch Time Switch Application in Bathroom INSTALLATION of Socket Outlets GENERAL Shaver Supply Unit Socket Outlet at Hazardous Area Socket Outlet of Surface