Lightning protection grounding common sense

Lightning protection grounding assembly, due to equipment aging, poor body performance, overdue service and later operation and maintenance to get rid of various notices, joined in the on-site improvement of poor solutions, consistent layout, poor construction quality and many other issues, always endangering the power grid Comfortable operation. The above takes care of some things that everyone should be aware of for lightning protection and grounding: ground network excavation. The local substations have been operating for a long time, and some have even been operating for up to 37 years. The testers can measure the grounding resistance every year, whether they can meet the requirements, and issue test reports, but rarely explain the details of the test data. Variety.

The structure is grounded. There are four error scenarios: one of the busbar structures is grounded through the main bar of the cement rod. Between the two switch frames, the metal member holding the hook string is used as a channel, and the ground is connected through the bolts at the connecting parts. The third lightning rod leads the lower wire through the main reinforcement of the cement rod to conduct. The four lightning rods were applied with a lower wire and were surrounded by the reinforced concrete pier. The gap is arranged horizontally. Most of the original 110kV transformer neutral point discharge gaps are installed vertically. The fact that years of operation has proved that the vertical discharge gap installation has many disadvantages. In the case of a despicable image, it is easy to form an icicle, which is effective and affects the comfort. The neutral point grounding down conductor is stably grounded at two points on the main network. . The neutral point of the transformer should have two ground leads connected to different locations of the main grounding grid, and each ground lead should meet the requirements of thermal fluctuations. The first equipment and equipment frame should have two ground leads. The ground leads connected at different locations, and each ground lead should meet the requirements of thermal fluctuations, and the connection lead should also be convenient for search and testing during the period. The single point of the neutral point of the transformer is grounded. Once the connection line has a problem, the equipment will be broken.

The expanded ground network should be connected to the original ground network at multiple points. The grounding resistance of the grounding grid will be tampered with the passage of time and its own erosion, and some may even exceed the standard. In order to reduce the grounding resistance of the main grid, it is a good action to lay another grounding grid. The local substation is adopted in the original according to the topography. At the end of the main network, a single delay of grounding piles is added, and the grounding resistance of the main network is high and low.

The comfortable distance between the main net and the lightning rod net. Over time, the grounding resistance of the main network and the lightning rod network will always be added, and some even exceed the standard. It is imperative to lay down the corresponding grounding network to reduce the resistance. Directly match the "trinity" wiring situation in the low-voltage surge arrester down wire correctly wired. The high voltage side of the substation is directly equipped with no surge arrester (since the incoming line is installed and the protection distance of the surge arrester does not exceed the large electrical distance between the surge arrester and the transformer, so it is omitted in the plan), the low voltage side is equipped with a low voltage surge arrester, low voltage surge arrester and transformer The neutral point of the low voltage side and the metal shell of the transformer are grounded all the way to form the so-called 'trinity' wiring situation of the transformer. The low-voltage side arrester leads the down conductor to hold the outer shell of the transformer as the discharge channel of the arrester, which is not in line with the technical requirements.