泊头市克雷安防雷器材科技有限公司

Introduction to non-metal grounding module

 

Non-metallic grounding modules are widely used in communications, broadcasting and other departments. It is formed by non-metallic composite materials with excellent electrical conductivity. The processing methods include casting molding and mechanical compression molding. In general, cast molding has loose structure, low strength, poor electrical conductivity, and unstable quality. Some small manufacturers use such a small amount of production; mechanical compression molding is formed by using equipment under a pressure of several to ten tons. Not only the dimensional accuracy is high, but the appearance is better. More importantly, the material structure is compact, the electrical performance is good, the resistance to large current surge is strong, and the quality is also quite stable, but the production cost is high, and mass production is adopted. When selecting the type, try to use the latter. Especially when the grounding body has the requirement of resisting large current or large inrush current (such as electric working place and lightning protection grounding), it is not suitable to use cast non-metallic grounding body. The non-metallic grounding body is a corrosion-free grounding body. Its stability, environmental adaptability and service life are the best among the existing grounding materials, and do not require regular modification and maintenance. The grounding area required for the construction of non-metallic grounding bodies is much smaller than the traditional grounding area. However, under different geological conditions, it is also necessary to ensure sufficient grounding area to achieve good results.

 

Grounding module classification

 

The graphite grounding module is divided into three-hole three-edge grounding module. Three-hole hexagonal grounding module Solid hexagonal grounding module Solid cylindrical grounding module Three plum-shaped grounding module Round grounding module Square grounding module Six kinds of grounding modules.

 

Low resistance grounding module characteristics

 

1. Reduce the contact resistance. The physical structure of the main material is similar to that of the soil. It can be integrated with the soil, so that the effective contact area between the grounding body and the soil is many times larger than that of the metal grounding body, which increases the effective area of ​​the grounding body. Greatly reduce the contact resistance between the grounding body and the soil, so it can significantly improve the grounding efficiency and reduce the land area occupied by the grounding grid.

 

2, the grounding resistance is stable: it has a strong moisture absorption and moisturizing ability, so that the soil around it is kept moist, to ensure that the grounding module effectively exerts the conductive effect; at the same time, the conductive properties of the conductive material in the grounding body are not affected by the dry humidity, high and low temperature, etc. The effect of the change, therefore, provides a stable grounding resistance.

 

3. Long service life: The main body itself is anti-corrosion material. Its metal skeleton is made of metal material with anti-corrosion treatment on the surface, which can meet the requirement of grounding resistance ≤ 4Ω. The grounding body is stable for a long time, and its use period is more than 30 years. .

 

4, it has moisture absorption, moisturizing properties, can withstand the low temperature of -40 ° C, the same applies to the northern cold regions. From the metal material with very good stability as the main body, the metal material with anti-corrosion treatment on the surface as a skeleton, squeezed by special equipment Compression molding.

 

5. Reducing the ground potential counterattack: Non-metallic materials form a low-resistance region with a relatively gentle change between the metal and the soil with a large difference in resistivity. When a large current strikes, the transient potential gradient of the grounding body and the grounding line can be lowered and reduced. The step voltage and the contact voltage reduce the probability of a ground potential counterattack.

 

4). Grounding down the line is required. Grounding down the line. At the junction of the surface, it is necessary to apply 2~3 times of epoxy asphalt varnish, FVC paint or other durable paint. The length of the underground section should be the part of the buried drag reducing agent. Not less than 20mm, the length of the upper part of the earth's surface is not shorter than 30mm.

 

5) Deep well grounding Deep well grounding is sometimes necessary. Usually the depth of the well is determined by finding a formation with low resistivity or groundwater, typically tens of meters. Drilling with special machinery during construction, the hole diameter is 80 ~ 150mm. Sometimes it is accompanied by partial blasting, which loosens the surrounding soil to fill the resistance reducing agent and expand the resistance reduction effect. The grounding electrode is drilled with a steel pipe having a through hole of Φ10 to 15 mm on the four walls. The prepared pressure reducing agent is injected into the tube by pressure, and the resistance reducing agent surrounds the steel pipe from the inner and outer sides through the wall hole and enriches the whole