Lightning protection grounding is divided into two concepts, one is lightning protection to prevent damage caused by lightning strikes; the other is electrostatic grounding to prevent static electricity from harm.
The lightning protection of the factory is divided into the overall structure lightning protection, which is the lightning protection of the main building. The main foundation is grounding pole and grounding strap to form a grounding grid with a grounding resistance of less than 10 ohms. It is then connected to the main body of the steel or steel structure of the main building. The cement concrete roof is connected to the lightning band or the lightning rod. The grounding test point is left on the ground outside the wall. The steel structure is directly led to the roof by using galvanized flat iron.
The grounding of the power supply system is divided into protective grounding and working point grounding. The protective grounding is the grounding of the live equipment casing. The grounding point of the working point refers to the grounding of the neutral line. The grounding grid is the same as the lightning protection grounding method, and the grounding resistance is less than 4 ohms. If the requirements are not met, the grounding electrode should be added. If the conditions are not good, the electrolyte should be added and/or the soil should be replaced. The working ground and protective ground are independently led out in the power distribution room, and the system can be combined into one. The working mode, such as ground and neutral, can also be combined into a power system (or equipment). The grounding system must be grounded repeatedly. There are also separate ways, the TN-S system. Zero land can no longer be combined.