Lightning protection grounding
resistance reducing material
Address: Wuluohou Industrial Zone, Weicun Town, Qingyuan District, Baoding City, Hebei Province
1. Product performance:
Jichangdi brand CD-03 (physical) resistance reducing agent is a new type of resistance reducing material produced on the basis of summarizing the two generations of CD-01 and CD-02 resistance reducing agents. This product completely overcomes the previous two generations. Existing unfavorable factors, the performance of the product has been greatly improved, and it is more anti-corrosive and conductive than the previous two generations of resistance reducing agents.
This product is purely physical. It completely eliminates the corrosive electrolyte. It uses non-electrolyte carbon powder as conductive material. Its conductivity is not subject to acid, alkali, salt; high and low temperature; dry humidity is limited due to carbon The element conductive material does not dissolve into water, and does not chemically react with metals. The slurry and soil are limited in permeation, and will not be lost due to the drop of groundwater level, dry weather, and rainy season after solidification. Therefore, the performance is more stable and longer.
2. Principle and function of resistance reduction:
This resistance reducing agent is a good electrical conductor. It can be used between the grounding body and the soil. On the one hand, it can be in close contact with the metal grounding body to form a large enough current flow surface; on the other hand, it can penetrate the surrounding soil , Reduce the resistivity of the surrounding soil, and form a low resistance area with gentle changes around the grounding body.
The resistance reducer itself has strong water absorption and moisturizing properties. After using the resistance reducer, it can maintain the moist state of the soil near the electrode for a long time. After solidification, the resistance reducing agent is weakly alkaline, has a compact structure, and has a corrosion protection effect on the electrode.
In addition, the resistance reducing agent also has a good pressure equalization effect, improves the potential distribution, thereby reducing the step voltage and protecting personal safety.
3. Main technical parameters and performance indicators:
1. Resistivity reduction: 50%-95% (the higher the soil resistivity, the more obvious the resistance reduction rate);
2. Stability and long-term effectiveness: The theoretical validity period of the resistance reducing agent is more than 30 years;
3. Water retention and water absorption are significantly higher than previous products;
4. Other performance indicators: See the attached table (Summary of test items of Wuhan High Voltage Research Institute of State Grid).
4. Calculation of dosage:
The resistance reducing agent is composed of multiple components, including electrolytes, curing agents, lubricants, high-efficiency preservatives and filling materials. It is in the form of black powder and is a good electrical conductor. Applying it between the grounding body and the soil, on the one hand, it can be tightly combined with the metal grounding body to form a large enough current flow surface; on the other hand, it can penetrate into the surrounding soil, effectively reducing the resistivity of the surrounding soil, and it is around the grounding body. A low resistance area with gentle changes is formed, so as to achieve the purpose of reducing the grounding resistance value.
5. Scope of application
CD-03 resistance reducing agent is suitable for the following types of high-demand grounding devices.
★Grounding devices for power plants, substations, and transmission lines;
★Grounding devices for various communication lines;
★The grounding device of the electronic computer room and microelectronic equipment;
★Grounding devices for petroleum, chemical, medical, oil storage, and high-rise buildings;
★Work grounding and protection of various power equipment, telecommunication systems and equipment, facilities, instruments and meters
★Grounding devices for TV towers, microwave stations, radio stations and radar stations; grounding and lightning protection grounding devices
The resistance-reducing effect is obvious, which can reduce the construction workload, and the grounding body can be used less. In particular, the horizontal grounding body can be used to replace the vertical grounding body that is difficult to construct (in mountainous areas and rocky areas, etc.). The construction is convenient, it can solve the difficulties of the limited construction site, can save a lot of metal materials, has long-term performance and stability, and has good anti-corrosion performance. It has good water absorption and water retention, is not easy to lose with water and soil, and is less affected by climate. Comprehensive technology and economy are good.
7. Calculation of dosage
The economical dosage of the resistance reducing agent should be determined by different soils. The laying thickness on the grounding body should be between 5-15cm. For the convenience of calculation, the recommended dosage is as follows:
8. Measuring method
The resistance reducing agent can be measured after backfilling and tamping, and the resistance value will decrease as time goes by and the soil settles. If the measured resistance value is abnormal (extra large or small), check whether there are metal buried objects near the measurement path.
9. the overall layout design of the grounding body
The overall design of the grounding body should depend on the terrain, topography, soil quality, etc. There are usually the following two types:
Vertical method: It is divided into one-shaped, mouth-shaped, cross-shaped and fishbone shape. This method only uses ground resistance agent around the vertical grounding body, and does not use it in the horizontal connection.
Horizontal method: divided into one-shaped, mouth-shaped, cross-shaped and fish-bone shape, only the horizontal grounding body is arranged, and the resistance reducing agent is used.
10. Matters needing attention
The resistance reducing agent must be protected from moisture and stored in a dry and ventilated place free from rain. The resistance reducing agent is a two-layer package, the inner bag is a sealed plastic bag, and the outer bag is a woven bag.