Electrical Equipment Code - Kostt

1 Electrical Equipment Code Prishtina July 2007 TABLE OF CONTENTS 0 Preface to this version of the Electrical Equipment Code .. 1 1 Introduction .. 1 2 Glossary and Definitions .. 2 3 Service Conditions .. 5 General .. 5 Normal Current Ratings of Equipment .. 5 Normal Service Conditions .. 5 Indoor Plant .. 6 Outdoor Plant .. 6 Protection and Control Equipment Operating 6 Fault Clearance .. 7 Multi-pole Opening/Tripping and Auto-reclosing .. 8 Special Service 8 4 Substations .. 10 Technical Requirements for Substations Connected to the Transmission System .. 10 General 10 Designing For Safety .. 10 Legal 11 Environmental Impact .. 11 Design Life of Installations .. 11 Operational 11 Maintenance Requirements .. 11 Interlocking .. 12 Current Transformers .. 12 Switchgear Secondary Isolation .. 12 Voltage Transformer Secondary Isolation .. 12 Earthing .. 12 Equipment Identification.

2 12 Secondary Equipment .. 13 Substation Auxiliary Cabling .. 14 Electrical Equipment Code i Segregation of Equipment owned by TSMO and System Users .. 14 Lifting Equipment .. 15 Substation Facilities .. 15 Site 16 Fire Protection .. 16 Disturbance Recorder .. 16 General Requirements Applicable to AIS Substations .. 16 Electrical Clearances .. 16 Safety Clearances/Distances .. 17 Clearances to Perimeter 18 Clearance to Roadways .. 18 Substation Profile .. 19 Earthing Devices .. 19 Portable Earthing .. 20 General Requirements applicable to GIS 20 20 AIS Connections .. 20 Portable Maintenance Earthing Devices (PMEDs) .. 20 Gas service connections .. 21 Pressure/Density Indication .. 21 SF6 Gas Alarm Scheme .. 21 Location of Light Current 21 Performance Requirements for all Switchgear .. 21 Jointing of Current Carrying Conductors .. 21 Primary 21 Routine Tests at Site.

3 22 Current Carrying Conductors .. 22 Conductor Jointing in Substations .. 22 Introduction to Conductor Jointing .. 22 Jointing 22 Preparation of Unplated/Untinned Surfaces of Bolted Joints .. 23 Preparation of Tinned or Plated Surfaces of Bolted Joints .. 23 Assembly of Bolted Joints .. 24 Service Performance of Bolted Joints .. 24 Gas Shielded Electric Arc Welded Joints (MIG TIG).. 24 Electrical Equipment Code ii Fusion Electric Arc Welding, Gas Brazing and High Temperature Soldering25 Explosive Jointing / Cold Pressure 25 Compression 25 5 Switchgear .. 26 General Technical Requirements .. 26 Compressed Gas .. 26 Operating Mechanisms and 27 Outage Constraints .. 27 Technical Requirements for Gas Insulated Switchgear .. 27 SF6 Gas Service Connections .. 28 Partial Discharge Measurement .. 29 Performance Requirements .. 30 Sulphur Hexafluoride Gas (SF6) .. 31 6 Circuit 31 General 32 General Requirements for Circuit breakers.

4 32 General Requirements for Mechanisms and Stored Energy Systems .. 33 General Requirements for Control Schemes and Circuitry .. 34 Additional General Requirements for Special Purpose Circuit breakers for Capacitor Bank Switching .. 36 Additional General Requirements for Special Purpose Circuit breakers for Shunt Reactor Switching .. 36 Performance Requirements .. 36 Performance Requirements for Special Purpose Circuit breakers for Capacitor Bank 37 7 Disconnectors and Earthing Switches .. 38 Rated Short-Time Withstand Current .. 38 Divided Frame Disconnectors and Earthing 38 Bus-transfer Duty .. 38 Rated Values of Mechanical Endurance for Disconnectors .. 39 Rated Values of Electrical Endurance for Earth 39 General Requirements for Disconnectors and Earth 39 Clearance Distances .. 39 Simultaneous Operation of Poles .. 39 Electrical Equipment Code iii Flexibility of Design and Setting Adjustment 39 Position Indication.

5 39 Mechanical Key 40 GIS Combined Disconnectors and Earthing Switches .. 40 Drive System Mechanical Interference 40 'Lockout' Interlock Keys .. 41 Earthing Switch Magnetic Bolt 41 Operations 41 Construction Materials and Protective Coatings .. 41 Operating Mechanisms, Ancillary Equipment and their Enclosures .. 41 'Sealing In' of Control 41 Drive Limit Switch .. 41 Control Switches .. 42 Auxiliary Switches .. 42 8 Substation Interlocking Schemes .. 42 General 42 Mechanical Interlocking .. 44 Performance Requirements .. 44 9 Solid Core Post Insulators for Substations .. 44 Type Tests .. 44 Routine Testing .. 45 10 Bushings .. 45 General 45 Performance Requirements .. 45 Type Test Requirements .. 46 Routine Test Requirements .. 46 11 Surge Arresters .. 47 General requirements for all Surge Arresters .. 47 Air Insulated Surge Arresters .. 47 Gas Insulated Surge Arresters .. 48 Functional and Performance Requirements.

6 48 Type Tests .. 49 Electrical Equipment Code iv Routine 49 Commissioning Tests .. 50 Condition Monitoring and Maintenance .. 50 12 Measurement Transformers .. 50 Current Transformers .. 51 Type Tests .. 54 Routine Tests .. 54 Routine Test Reports .. 55 Voltage Transformers .. 56 Performance Requirements of VTs .. 56 Type Tests .. 58 Routine Tests .. 59 Routine Test Reports .. 59 13 60 Rise of Earth Potential .. 61 Earth 63 Earth Electrode 64 Test Facilities .. 64 Equipment Connected to the Main earth system .. 65 Installation .. 66 Portable Earthing .. 66 Steel Support Structures .. 67 Fences .. 67 Access/Egress Gates .. 68 Temporary Fences .. 69 Terminal Towers .. 69 Gas Insulated Substations .. 69 Anti-climbing Precautions Along the Tops of 70 Design Life of Installation .. 70 Test Requirements .. 70 14 Auxiliary Supplies .. 70 Performance Requirements .. 72 Alternating Current Supplies.

7 72 Electrical Equipment Code v Direct Current Supplies .. 72 15 Protection and Protection Grading .. 73 Protection Principles .. 73 Use of Differential Protection on Short 73 Supervision of Circuit Breaker Main Contacts and Trip Circuits .. 74 Fault location facilities on long overhead line circuits .. 74 Power System Instability and Under Frequency .. 74 400kV Network .. 75 220 kV Network .. 75 110kV Network .. 76 Breaker Fail 76 Use of shared Current Transformers .. 76 Transformer Protection .. 77 Overcurrent Protection on Networks of System Users .. 77 16 Power 79 Transformer Construction .. 79 Transformer Ratings and Connections .. 80 Pumps and 80 81 Guaranteed Transformer Losses .. 81 Loss 81 Tapchangers .. 82 Tapchanger Control .. 82 System Users Equipment .. 82 Surface Treatment of Transformer Tank and Accessories .. 83 Transformer 83 83 Protection against Catastrophic Failure.

8 83 Fire 83 Environmental Protection .. 84 System Users Transformers Special Requirements .. 85 17 Overhead Lines .. 85 Tower 85 Electrical Equipment Code vi Electrical Equipment Code vii Tower 85 Tower 86 Anti-climbing Devices .. 86 Step 86 Identification Plates and Signs .. 87 Safety 87 Circuit and Tower Number Identifier .. 88 Combined Safety Sign and Circuit and Tower Number Identifier Plate .. 89 Phase Identifier .. 89 Tower Top Identifier .. 90 Finish of Tower Steelwork .. 91 Tower 91 Insulators and 91 Conductors .. 94 Earthing Conductors .. 94 Line Clearances .. 95 Line Crossings .. 95 Air Navigation .. 96 Rights of Way and Tree 96 18 Disputes 96 19 Management of the Electrical Equipment 97 Unforeseen Circumstances .. 97 In this Electrical Equipment Code .. 97 Affecting the ability of Parties to Comply with this Code .. 97 Electrical Equipment Code 1 0 Preface to this version of the Electrical Equipment Code This version is intended as final taking account of the comments received on the drafts that were prepared for review within Kostt and by other interested parties to allow the development of a final draft to be presented to the steering group.

9 In a few places in this version, there still appears [xx] in place of figures. At these points, either figures specific to the Kostt network are required or information of particular Equipment used by Kostt or KEK Networks. Attention is drawn to the areas where responses are still required by Kostt in the paper entitled Analysis of Comments on the Sixth Draft of the Electrical Equipment Code 1 Introduction This Electrical Equipment code sets out the requirements for Equipment forming part of the network of the TSMO and for Equipment of system users at the point of connection with the network of the TSMO. It relates to Equipment operating at nominal voltages of 110kV, 220kV and 400kV forming part of the main system of the TSMO and, where appropriate, to Equipment connected to tertiary windings of main transformers at a nominal voltage of 10kV or Where it refers specifically to the network of the TSMO, it defines the ratings and general requirements for plant, Equipment and apparatus to be connected to the TSMO network by, or on behalf of, the TSMO, taking account of the characteristics of the network in the area that the Equipment is to be connected.

10 Where it refers to Equipment of system users, it defines the general requirements for plant, Equipment and apparatus at the connection point between the networks of the system user and of the TSMO and the range of Equipment ratings used by the TSMO that will be used at the connection point as defined in the connection agreement. In general, ratings are selected from the range of values given in the appropriate IEC documentation and will be applied throughout the TSMO network. Where absolutely necessary, other ratings may be specified or agreed by TSMO where interconnection is required with parts of the network that were constructed to older specifications that are incompatible with current standards. Where this occurs, Equipment ratings will be specified on a site specific basis only, preferably utilising another IEC value or design arrangement that is compatible with the safety and security levels utilised by the TSMO for its network and to ensure compliance with the requirements of the UCTE.