1 General Provisions
1.0.1 This code is formulated with a view to make cable design of electric engineering to live up to state-of-art technology, economy and rationality, safety and usability and also convenient for construction and maintenance.
1.0.2 This code is applicable to selection and burying design of power supply cable and control cable which is 500kV or below in construction and extension of electric engineering.
1.0.3 Towards cable design of electric engineering, not only the requirements stipulated in this code, but also those in the current relevant ones of the nation shall be complied with.
2 Terms
2.0.1 Fire resistance
It is a characteristic property that sample cable can remain on-stream performance under specific test conditions for a specific time although burnt in fire.
2.0.2 Fire resistant cable
It is a kind of cable with fire resistance.
2.0.3 Flame retardancy
It is a characteristic property of cables that cable is ignited under specified test conditions and its flame only spread in delimited region and its after-flame or after-bright can go out by itself in limited time since the flame source is removed.
2.0.4 Flame retardant cable
It is a kind of cable with fire-retardancy.
2.0.5 Dry-type cross-linked
It is a cross linked process used to reduce remarkably the moisture of cross-linked polyethylene insulation materials during manufacturing.
2.0.6 Water tree
It is a brief term to describe a phenomena when insulating layer has arborization hair-crack while cross-linked polyethylene cable is in service.
2.0.7 Metallic-plastic composite water barrier
It is a water barrier that is made up of a composite tape with a thin metallic layer of aluminum or aluminum foil contained in the plastics to wind along the cables.
2.0.8 Thermal resistance
It is a physical quantity defined by thermal ohm principle for the one-dimension exothermic process using the analytic method for thermal network to calculate current carrying capacity of cable.
2.0.9 Auxiliaty ground wire
It refers to voltaic wire laid in parallel with high-voltage single-core cable line and connects with ground at both ends to establish a circuit for induced current.
2.0.10 Direct burying
It refers to a cable laying method that lay cables in underground ditch whose bottom covered with underlayer, as well as cover cable with mantle and add fender apron to level the ground.
2.0.11 Channel
It is a covered trough structure without brackets, which can only contain small quantity of cables.
2.0.12 Manhole
Covered pit-type structure for cables that used for installing the accessories of cable joints, etc., or for operations of drawing cables.
2.0.13 Cable buildings
It is a general term for the structures of cable troughs, channels, bank tubes, tunnels, interlining, shaft-wells (sidetracking well), manholes, etc. provided for laying cables or installing accessories.
2.0.14 Slip fixing
It is a fixing way to allow cables to have axial changes in angles along the fixing points caused by expansion and contraction due to temperature change and a slight cross sliding.
2.0.15 Rigid fixing
It is a fixing way to clip cables that will not cause the cables to have a displacement with the expansion caused by heat and contraction by cold.
2.0.16 Snaking of cable
1 General Provisions
2 Terms
3 Selection of Types and Cross Sections of Cables
3.1 Material of Cable Conductor
3.2 Number of Cores for Power Cables
3.3 Insulation Level of Cables
3.4 Insulation Type of Cables
3.5 Types of Protective Coverings for Cables
3.6 Control Cables and Metallic Screen
3.7 Cross Sections of Power Cables
4 Selection and Configuration of Cable Accessories
4.1 General Provisions
4.2 Oil-supply System of Self-contained Oil-filled Cables
5 Cable Laying
5.1 General Rules
5.2 Selection of the Way of Cable Laying
5.3 Direct burying underground
5.4 Laying in protection conduits
5.5 Laying in cable buildings
5.6 Laying in other public facilities
5.7 Laying underwater
6 Supporting and Fixing of Cables
6.1 General Rules
6.2 Cables Brackets and Trays
7 Cable Fire Prevention and Retardation
Appendix A Maximum permissible temperature of common power cables conductor
Appendix C Permissible 100% continuous current capacity of common power cables of 10kV and below 10kV
Appendix E Methods to calculate permissible minimum conductor-section-area according to short-circuit thermostable conditions
Appendix F Formulae for normal induction potential of single-core cable metallic layer in AC system
Appendix G Additional length when installing and measuring cables of 35kV and below
Explanation of Wording in this code
1 General Provisions
1.0.1 This code is formulated with a view to make cable design of electric engineering to live up to state-of-art technology, economy and rationality, safety and usability and also convenient for construction and maintenance.
1.0.2 This code is applicable to selection and burying design of power supply cable and control cable which is 500kV or below in construction and extension of electric engineering.
1.0.3 Towards cable design of electric engineering, not only the requirements stipulated in this code, but also those in the current relevant ones of the nation shall be complied with.
2 Terms
2.0.1 Fire resistance
It is a characteristic property that sample cable can remain on-stream performance under specific test conditions for a specific time although burnt in fire.
2.0.2 Fire resistant cable
It is a kind of cable with fire resistance.
2.0.3 Flame retardancy
It is a characteristic property of cables that cable is ignited under specified test conditions and its flame only spread in delimited region and its after-flame or after-bright can go out by itself in limited time since the flame source is removed.
2.0.4 Flame retardant cable
It is a kind of cable with fire-retardancy.
2.0.5 Dry-type cross-linked
It is a cross linked process used to reduce remarkably the moisture of cross-linked polyethylene insulation materials during manufacturing.
2.0.6 Water tree
It is a brief term to describe a phenomena when insulating layer has arborization hair-crack while cross-linked polyethylene cable is in service.
2.0.7 Metallic-plastic composite water barrier
It is a water barrier that is made up of a composite tape with a thin metallic layer of aluminum or aluminum foil contained in the plastics to wind along the cables.
2.0.8 Thermal resistance
It is a physical quantity defined by thermal ohm principle for the one-dimension exothermic process using the analytic method for thermal network to calculate current carrying capacity of cable.
2.0.9 Auxiliaty ground wire
It refers to voltaic wire laid in parallel with high-voltage single-core cable line and connects with ground at both ends to establish a circuit for induced current.
2.0.10 Direct burying
It refers to a cable laying method that lay cables in underground ditch whose bottom covered with underlayer, as well as cover cable with mantle and add fender apron to level the ground.
2.0.11 Channel
It is a covered trough structure without brackets, which can only contain small quantity of cables.
2.0.12 Manhole
Covered pit-type structure for cables that used for installing the accessories of cable joints, etc., or for operations of drawing cables.
2.0.13 Cable buildings
It is a general term for the structures of cable troughs, channels, bank tubes, tunnels, interlining, shaft-wells (sidetracking well), manholes, etc. provided for laying cables or installing accessories.
2.0.14 Slip fixing
It is a fixing way to allow cables to have axial changes in angles along the fixing points caused by expansion and contraction due to temperature change and a slight cross sliding.
2.0.15 Rigid fixing
It is a fixing way to clip cables that will not cause the cables to have a displacement with the expansion caused by heat and contraction by cold.
2.0.16 Snaking of cable
Contents of GB 50217-2007
1 General Provisions
2 Terms
3 Selection of Types and Cross Sections of Cables
3.1 Material of Cable Conductor
3.2 Number of Cores for Power Cables
3.3 Insulation Level of Cables
3.4 Insulation Type of Cables
3.5 Types of Protective Coverings for Cables
3.6 Control Cables and Metallic Screen
3.7 Cross Sections of Power Cables
4 Selection and Configuration of Cable Accessories
4.1 General Provisions
4.2 Oil-supply System of Self-contained Oil-filled Cables
5 Cable Laying
5.1 General Rules
5.2 Selection of the Way of Cable Laying
5.3 Direct burying underground
5.4 Laying in protection conduits
5.5 Laying in cable buildings
5.6 Laying in other public facilities
5.7 Laying underwater
6 Supporting and Fixing of Cables
6.1 General Rules
6.2 Cables Brackets and Trays
7 Cable Fire Prevention and Retardation
Appendix A Maximum permissible temperature of common power cables conductor
Appendix C Permissible 100% continuous current capacity of common power cables of 10kV and below 10kV
Appendix E Methods to calculate permissible minimum conductor-section-area according to short-circuit thermostable conditions
Appendix F Formulae for normal induction potential of single-core cable metallic layer in AC system
Appendix G Additional length when installing and measuring cables of 35kV and below
Explanation of Wording in this code
