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2. Basic grounding refers to the use of steel mesh in the underground foundation of a building as a grounding body instead of an artificial grounding pole.
3. Joint Grounding Method The joint grounding method is also called the single point earthing method, that is, all earthing systems share a common "ground". Joint grounding has the following features:
(1) The grounding system of the entire building constitutes a cage pressure equalizer. For direct lightning strikes, the points on the same floor of the building are relatively uniform; for induced lightning, cage-type pressure equalizers and frame-type structures of the building are also externally-interfering magnetic fields. Can provide 10-40dB of shielding effect;
(2) Generally, the grounding resistance of the joint grounding system is very small, and there is no coupling effect between various grounding bodies, which is conducive to reducing interference;
(3) It can save metal materials and occupy less land. It is not difficult to see from the above that the joint grounding method can effectively suppress the interference of external high-voltage transmission lines.
4. Protective grounding: In order to protect personal safety and prevent contact with electricity, the exposed conductive part of the equipment is grounded, which is called protective grounding. There are two types of protective grounding: one is that the exposed conductive parts of the equipment are directly grounded through their respective ground protective wires; the other is that the exposed conductive parts of the equipment are grounded through a common protective wire. 5. In a range of joint grounding, called common ground.
6. GB50057-2010 definition of equipotential bonding "Connect separate devices, conductive objects, etc. with equipotential bonding conductors or surge protectors to reduce the potential difference between the lightning currents generated between them."
The construction needs to be carried out according to the engineering design. The requirements in the construction drawings have been stated. For the practice, refer to the relevant national standard atlas. Grounding resistance requirements are generally: direct lightning grounding is less than 10 ohms; independent (dedicated) grounding is less than 4 ohms; joint grounding is less than 1 ohm. Special occasions or equipment have special requirements according to their requirements.
1) Working ground: In order to ensure the grounding of the power equipment to achieve the normal working requirements, it is called working ground. In the power system where the neutral point is directly grounded, the neutral point of the transformer is grounded or the neutral point of the generator is grounded.
2) Protective grounding: In order to protect personal safety and prevent contact with electricity, grounding the exposed conductive part of the equipment is called protective grounding. There are two types of protective grounding: one is that the exposed conductive parts of the equipment are directly grounded through their respective ground protective wires; the other is that the exposed conductive parts of the equipment are grounded through a common protective wire.
3) Repeated grounding: In the neutral grounding system, in order to ensure safe and reliable protection, in addition to working ground at the neutral point of the transformer or generator, the necessary grounding is also performed at other places of the protective line, which is called repeated grounding. .
4) Protection of the neutral line: In the 380/220V low-voltage system, the neutral point is directly grounded, and usually the outer shell of the electrical equipment is connected to the neutral line, which is called low-voltage protection to the neutral line. GFW Arrester Cable Tower, POE Lightning Protection Device, Cathodic Protection Grounding System, Lightning Protection Grounding Project, Surge Protector, Insulated Lightning Lead Down Wire
1. Lightning protection grounding refers to the grounding of lightning protection devices (such as lightning rods, lightning protection strips, lightning protection nets, and lightning arresters).