The electromagnetic induction of the bridge bus slot electromagnetic induction on the protected ground line is 50% higher by the actual measurement. At the same time, the three-phase conduction distance PE distance is different, the inductance is not equal. When the line is long, the three-phase is seriously unbalanced under the fault current. The outer contact can not reach the busbar, which can prevent the external material from short circuit; because of the PE line of the dense busbar of the cable bridge of Shandong cable bridge, it is also safe to touch the shell; the busbar slot is small in unit volume and is more beautiful after installation; it is convenient for feeding and maintenance.
In this way, the grounding mode is better than the PE alone, both in short time and in continuous short circuit. Therefore, the International Electrotechnical Commission announces and promotes the use of the busbar as the grounding conductor. The connecting parts of each functional unit of the closed busbar and the copper surface on the movable joint must be cleaned up, and the shell and insulator should be cleaned before the installation of the remnants. The electric lines of high pressure, low pressure and emergency power supply in the shaft should maintain 0.30m and above distance or take isolation measures, and the high voltage lines should have obvious signs.
The interphase short circuit board of the outer shell should be properly connected, the interphase support plate should be firmly installed, the insulating shell should be insulated, the torque of each connection part of the outer shell is fastened to the plate hand, the contact surface should be closed well, the fastener of the busbar groove must be hot-dip galvanized. Strong and weak electric circuits are set up in different shafts under suitable conditions.
The non magnetic material aluminum alloy shell with good conductivity is used as the protective earth wire, surrounded by the conductive row. As the Shandong cable bridge is as close as possible to the three-phase bus, the reactance can be minimal, and the distance between the protective ground line and the three phase bus is equal, and the reactance is the same.
If the condition restrictions must be used together, the strong and weak lines should be arranged on either side of the shaft or isolation measures to prevent strong electricity from interfering with weak electricity. The torque bolt of each connection part of the dense busbar shell needs to be fastened to the plate hand, and the contact surface is well closed; when the installation is installed, it is necessary to carefully compare the dense busbar system diagram, check all specifications and models to avoid blind installation, and cause the rework to affect the quality of construction and installation.
The highlights of this article are from Ji'nan cable tray. Please click on our official website: /, thank you for coming.