Service hotline:
Your location：Services
Grounding concept
The soil on the earth we are living on features low resistance, high capacitance, and absorbing infinite electric charges without potential change. With these features, it can be used as an electrical article of reference potential, and its potential can be artificially defined as a zero potential, which also known as electric"earth.
And, Grounding is to connect power system or electrical device or a certain part of building facilities with earth electrode via grounding wire. An grounding system with long-lasting low impedance is an important safeguard for the safe and stable operation of modern electrical facilities, and besides the fact that it ensures the safety of personnel and equip ment, the investment and operation in it has an extremely important economical efficiency.
Types of common used grounding materials
Galvanized steel
In the world, there are a few countries, represented by China, India and the former Soviet Union. use steel as the main grounding material in traditional engineering. Enjoying low cost of one-time investment, convenience of purchasing and low cost of construction thought, the material has low corrosion resistance and short service life.
Pure Copper(Red Copper)
Most countries in the world and our key engineering projects under construction all use pure copper as grounding material, as this kind of material features good conductivity and high corrosion resistance. But this kind of projects has high cost of onetime investment, which leads not to the advantage of economic performance
Non-metal Grounding Module
This kind of products uses carbon-based graphite, which is made into various shapes under high temperature and high pressure and fixed with steel connector inside, as the main material. It features the conductivity lower than all other kinds of metals,low mechanical strength of graphite, fragility, and inconvenient storage transportation, installation and maintenance, as well as the tendency of graphite to bu burst under strong transient current shock; the steel connector itself has low resistance to corrosion. and short service life both the above two factors shall cause failure of the entire grounding system.
Compound Grounding Products (on Grounding)
This kind of products is invented and first applied by foreign country, and introduced into China in the past more than ten years The products use hollow copper as the grounding electrode, which can be filled with water soluble and decomposable compound in the middle, and with ion-releasable and electrolyzable compound filler in the extemal, with which to lower the grounding resistance by improving the conductivity of the soil around through the electrolytic ion released Meanwhile, the compound filler in the extemal can effectively resist the corrosion from various organic salt, acid, alkaline matters and microbial organic compounds in the soil on metal grounding electrode. This kind of products is expensive, and applies only to vertical grounding under bad soil environment
Copper Coated Steel Products (Copper Coated Steel, Continuously Casted Copper Clad Stee)
This kind of products combined the high conductivity and corrosion resistance of copper with the high mechanical strength and low cost of steel, which achieved complementary advantages At present, the copper plated steel products have been provided with well-established certification and standard systems, such as UL. CE. IEEE. in the world. while none international standard is for the reference of continuously casted copper clad steel products.
Design standards and specifications for grounding systems
Domestic standard
○ GB 50169-2006 "Electrical Installation Engineering Grounding Device Construction and Acceptance Specifications"
○ GB 14050-2008 "Types and Safety Technical Requirements for System Grounding"
○ GB 50057-2010 "Code for lightning protection design of buildings"
○ GB 50343-2012 "Building Electronic Information System Lightning Protection Technical Specifications"
○ GB 50065-2011 "Code for Grounding Design of AC Electrical Installations"
○ GB / T 21698-2008 "Technical Conditions for Composite Grounding Body"
○ GB 16895.3-2004 "Electrical installations of buildings - Part 5-54: Selection and installation of electrical equipment, grounding arrangements, protective conductors and protective coupling conductors"
○ GB / T 17949.1-2000 "Guidelines for measurement of soil resistivity, grounding resistance and ground potential of grounding systems - Part 1: General measurement"
○ GB 16895.9-2000-T "Electrical installations of buildings - Part 7: Requirements for special installations or locations - Section 707: Grounding requirements for spare electrical installations of data processing equipment"
○ GB 16895.17-2000-T "Electrical installations of buildings - Part 5: Selection and installation of electrical equipment. Section 548. Grounding equipment and equipotential bonding of information technology equipment"
○ GJBZ 25-91 "Guide to Designing Grounding, Lap and Shielding for Electronic Equipment and Facilities"
○ DL/T 1312-2013 "Technical conditions for copper-clad steel for electric power engineering grounding"
○ DL/T 1312-2013 "Technical Conditions for Slow-release Ion Grounding Devices for Power Engineering"
○ DL/T 1315-2013 "Technical Conditions for Exothermic Flux for Power Engineering Grounding Devices"
○ DL/T 1342-2014 "Materials and connectors for electrical grounding engineering"
○ DL 475-2006 "Guidelines for Measuring Characteristic Parameters of Grounding Devices"
○ DL/T 5091-1999 "Technical Guidelines for Grounding Design of Hydropower Plants"
○ QX/T 104-2009 "Grounding Reducing Agent"
○ YD/T 1429-2006 "Technical requirements and test methods for lightning protection systems in communication stations (stations)"
○ SH 3097-2000 "People's Chemical Electrostatic Grounding Design Specification"
○ Q/GDW 466-2010 "Technical Conditions for Copper-clad Steel for Electrical Engineering Grounding"
○ Q/GDW 467-2010 "Guidelines for Exothermic Welding Technology for Grounding Devices"
Comparison of common grounding materials
| Contrast content | Traditional galvanized steel | Copper | Graphite grounding module | Liangou series copper-plated steel |
| Production Process | Hot galvanizing | Copper | Metal core layer peripheral die casting | Four-dimensional continuous plating |
| Service life | 3—10years | Over 100 years | 3—10years | Over 100 years |
| Grounding stability | Unstable | Stable | Unstable | Stable |
| Thermal stability | General | Good | Difference | Good |
| Mechanical strength | Good | general | Very poor | Good |
| Construction work surface | Very large | Larger | Very large | Smaller |
| Price comparison | One-time investment is lower | expensive | Slightly higher than the price of traditional steel grounding | Slightly higher than the price of traditional steel grounding |
| Maintenance is difficult | Perennial maintenance, easy to corrode | Maintenance free | The metal core is easy to corrode, and the internal steel core has a small cross-sectional area, which does not meet the mechanical and thermal effects under lightning strike conditions. | Maintenance free |
| Conductive properties | 8.6% of the base conductivity of pure copper | Conductivity 100% | Lower than all kinds of common metal conductors | High frequency current conduction is equivalent to pure copper |
| Welding process | Traditional electric welding | Gas welding or exothermic welding | Traditional electric welding | Exothermic welding |
| technical standard | National standard | National standard | No standard | UL, CE, IEEE, power line standards |
