1.0.1 This code was formulated especially to make the earthing design of AC electrical installations be able to guarantee the safety of electrical installations and human beings during the operation and fault of power system as well as make the earthing design be with advanced technology and be economical and rational.
1.0.2 This code applies the earthing design of the electrical installations for power generation, transformation, transmission and distribution in the high voltage high-voltage electrical installation with nominal AC voltage above 1kV to below 750kV and the earthing design of low-voltage electrical installation at and below 1kV.
1.0.3 The earthing design of AC electrical installations shall follow certain design procedures. The determination of the design scheme and the adoption of the materials of earthing conductor and earthing electrode shall be in accordance with local conditions. For the relatively important power plants and transformer substations in the region with complex soil regime, the earthing design of the earthing grid should be determined through scheme comparison by numerical calculation with computer dependent program.
1.0.4 The earthing design of AC electrical installations shall not only comply with this code, but also shall comply with those specified in the relevant current national standards.
1 General Provisions
2 Terms
3 High-Voltage Electrical Installtiaon Earthing
3.1 General Requirements
3.2 Range of the Protective Earthing
4 Earthing Grid of Power Plant and Transformer Substation
4.1 General Priovisions of Earthing grid Design of Power Plant and Transformer Substation at 110kV or Above
4.2 Requirements for earthing resistanceand Average Voltage
4.3 The design of Horizontal Earthing Network
4.4 Earthing of Gas Insulated Substation (GIS)
4.5 Earthing of Lightning Protection and Static Protection
5 High-voltage Overhead and Cable Line Earthing
5.1 Earthing of High-voltage Overhead Line
5.2 6kV~220Kv Cable Line Earthing
6 Earthing of High-voltage Electrical Distribution Devices
6.1 Earthing Resistance of High Voltage Electrical Distribution Devices
6.2 Earthing Installation of High-Voltage Power Distribution Electrical Devices
7 Low Voltage System Earthing Type, Overhead Line Earthing, Earthing Resistance of the Electrical Installation and Protective Equipotential Bonding System (PEBS)
7.1 Low Voltage System Earthing Type
7.2 Earthing of Low-Voltage Overhead Line, Earthing Resistance of the Electrical Installation and Protective Equipotential Bonding System (PEBS)
8 Earthing Installation and Protective Conductor of Low-Voltage Electrical Installation
8.1 Earthing installation
8.1.1 Earthing installationof the low-voltage electrical installation shall meet the following requirements:
8.2 Protective Conductor
8.3 Protective Bonding Conductor
Appendix A Calculation Method of Power-Frequency Earthing Resistance of Artificial Earthing Electrode in Soil
Appendix B Calculation Method of Earthing Fault Current and Earth Potential Rise Through Power Plant and Substation Earthing Grid
Appendix C Surface Layer Decrement Factor
Appendix D Calculation Method of Touch Potential Difference and Step Potential Difference of Earthing Grid in Uniform Soil
Appendix E Thermal Stability Check of Earthing Conductor of High Voltage Electrical Installations
Appendix F Calculation Method of Earthing Resistance of Pole Tower of Overhead Lines
Appendix G Calculation Method of Coefficient k
Appendix H Specification of Low Voltage Earthing Configuration, Protective Conductor and Protective Bonding Conductor
Appendix J Resistivity Reference Value of Soil and Water
Explanation of Wording in This Code
List of Quoted Sandards
