Selection of dense insulated busway and air insulated busbar planting
Reasonable selection of bus ducts can greatly improve the safety and reliability of the transmission and distribution system. In view of the different characteristics of both dense and air types, it is recommended to select dense insulated bus ducts for main lines, feeder parts and places with higher current levels of the distribution system; for places with more branches and lower current levels, you can choose air Insulated busway. In summary, the best use plan is: choose densely insulated bus ducts for large currents, and choose air insulated bus ducts for small currents. Its advantages are: full current carrying capacity, low loss, balanced reactance, easy to use, and reduced cost.
It is recommended to choose the specific range: the rated current above 1250A should be selected with densely insulated busway; below 1250A should be selected with air insulated busway or densely insulated busway. The reason why it is not suitable to use air-insulated busbars above 1250A is: large loss and high cost. Example: The low voltage side of a substation substation in Tianjin has a current rating of 3150A. In the early stage, an air-insulated busbar slot was selected.The area of its conductor is selected according to the cross-sectional area of the conductor of the densely insulated busbar slot (same current level). In the field sampling test, the temperature rise value has reached 90K, which is 30K higher than the standard. After adjustment, the densely insulated bus bar was selected. After the test, the temperature rise was only 50K, and the product met the standard requirements.
When the user selects the bus duct, the type and protection level of the bus duct should be determined according to different places of use, and the current level of the bus duct should be determined according to the required capacity. It is worth noting that the busbar products provided by the factory should be consistent with those that passed the comprehensive type test. Strictly avoid type testing is one product, but another product is provided to users. The power transmission test in the project cannot be used as the basis for comprehensively checking the performance of the bus duct. The power transmission test current in the project is very small and cannot reach full-load operating conditions, which cannot explain any problems. The busbar test run should be a long-term, full-load operation, so as to assess whether the busbar current-carrying capacity has reached the specified rating and the reliability of the insulation material.
Add: 4th floor,Pingan group industrail park,Pingan street office,Jinan city ,Shandong