In order to protect the buried metal structure from the influence and damage of AC interference, grounding the buried structure is an effective drainage measure to eliminate the influence of AC interference. Through grounding, the induced AC current can be directly removed from the buried structure. However, it also has an important impact on the cathodic protection system of buried structures, which leads to the loss of DC protection current. Therefore, when installing grounding drainage, DC isolation measures should be taken between buried structures and grounding electrodes to prevent the loss of cathodic protection current. In some of the main isolation measures, DC decoupling device is a good protection device to discharge AC and isolate DC.
For the buried metal pipeline system which may be affected by AC interference, grounding can be used as a protective measure to prevent AC interference by selecting the number of grounding electrodes and grounding resistance required for per unit length of pipeline economically and reasonably. In the construction of buried metal structures, it is very convenient to place strip grounding electrode in the pipe trench. If the soil resistivity decreases with depth, it is advisable to select a deep grounding electrode. It has the advantages of not occupying too much space, especially suitable for installation after construction. In addition, when using deep grounding electrode, the ideal grounding resistance can be obtained by connecting the corresponding length of grounding electrode. In this case, especially in heterogeneous soil, it is better to measure the grounding resistance when installing the grounding rod, for example, once every grounding rod is connected.
Galvanized steel is usually used as grounding material. For deep grounding body, assembled galvanized rod with diameter of at least 20 mm is often used. The size of grounding body with these cross-sectional areas is sufficient for the current load they carry as long as they are distributed along the disturbed track.
Shandong Linyi Bosi conductive materials Co., Ltd. is a high-tech enterprise specializing in the production of MMO flexible anode, conductive polymer flexible anode and titanium coated anode, mainly providing cathodic protection technology, engineering design, installation and technical services. Tel: 0539 3712117, 15588026668.
What are the protective measures against AC interference?
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