Accordance with the relevant industry data show that in 2005 China's total demand market Busway products nearly 10 billion yuan, from 2000 to 2005, the annual market growth rate of about 20%. Consider this year the market of raw materials (mainly copper conductor) price factors, is expected to total market demand in 2006 of nearly 13 billion yuan. With the vigorous development of China's economy sustainable, domestic Busway is expected in the next few years the market will maintain a 20% growth. So the number of market demand, the Busway products can develop rapidly and widely used in the power system.
Its structure and purpose into dense insulation, air-insulated, air additional insulation, fire-resistant, resin insulation and sliding touch Busway; their shell material into the steel casing, steel and aluminum alloy shell and mixed housing Busway ; its sub-conductor material copper conductor and aluminum conductor busbar.
Busbar system more commonly used in transformers and distribution as well as the connection between the cabinet by the power distribution center (distribution panels, cabinet) was beginning to load the trunk cabling way power supply system. System current level is usually 250 ~ 5000A, rated voltage 400 ~ 1000V, protection class IP40 ~ IP65, according to the number of conductors arranged three-phase four-wire and three-phase five-wire system (creation of independent PE row, while some manufacturers offer aluminum enclosure Grounding PE in the form as a whole). In the busbar system generally consists of the following elements: feeder busbar (without socket) or plug-in bus (with jack) line segment unit; and transformers, power distribution cabinets and other equipment interface into (out of) line unit; commutation unit has an L-shaped cells, T-cells, Z-type unit; expansion unit has expansion joints bus unit; plug-in unit with plug box unit. All units are usually carried out by the manufacturer Busway standard design can also be carried out according to project needs situ measurements taken after the non-standard design, and installation to meet user needs.
Busway selection usually from the following aspects to be taken into account: fire protection requirements, insulation materials to be flame retardant, heat better performance at high temperatures does not release toxic gases, the structure to prevent the chimney effect, preference should be given intensive insulation Busway, such as the use of air insulation type, you need online slots per housing unit setting fire retardant partition; pairs particularly important place in order to ensure the fire emergency power to maintain the work, should be used in fire-groove.
As for the installation site, first consider the tank shell protection grade, followed by construction structure trough shape, mounting brackets and span of the form: indoor use in the workplace, such as large-capacity substation to improve the cooling effect can be using IP30-rated busbar; interior common tasks, such as floor electrical power distribution between the inner shaft and, in order to ensure security, should be used no less than IP40 grade Busway; interior damp place or a splash of water required for the ensure its security in the event splashing water can still work, should be used no less than IP54 grade Busway; outdoors or have special requirements, such as anti-water, anti-corrosion and anti-surf sites, respectively resin insulated busbar; big span spaces should be used in case enhanced busbar; rated current, should technical performance, heat dissipation, and prices to be taken into account, the current market more choice of thermal performance and low energy consumption and a good low impedance intensive aluminum shell insulation Busway.
Under operating current (IB) to select the correct busbar rated current (IN) size, (IN) size basis having the manufacturer's product standards busbar current rating selection.
Currently, the vast majority of manufacturers due Busway some old design and manufacturing specifications influence on the choice of the tank is still copper-based conductors. However, copper prices rose sharply in recent years, making it the high cost, which is the manufacturer's market expansion will bring greater impact. Rational allocation of resources combined with the market and price factors, the domestic Busway products made of copper busbar conductors to aluminum busbars material transfer material to a product trends.
Manufactured from aluminum busbar bus conductor in some foreign countries has been widely used, its manufacturing technology and process has become mature. In recent years, some brands of domestic bus manufacturers have been providing a high quality aluminum conductor busbar, and has practical applications in engineering and design units obtained user recognition and praise, demonstrated its unique advantages. This paper from copper and aluminum conductors physical properties, chemical properties, electrical properties of aluminum conductors to further explore the feasibility instead of copper conductors.
Because copper conductor and aluminum conductor cross-sectional shape similar, so the manufacturer can be found in the domestic Busway original copper conductor not make major changes in the product mix Busway case design, manufacture aluminum conductor busbar, with its emphasis on improving production process (such as improved conductor surface treatment process to enhance and protect the quality of the coating with aluminum conductor) and the creation of the associated tooling equipment. Therefore aluminum conductor busbar in the technology, the economy and the copper conductor busbar comparative advantage is its application to get the focus of a large number, the comparison is as follows:
Copper, aluminum conductor metals comparison: copper density 8.9g/cm3, the density of aluminum 2.7g/cm3; conductivity of copper after silver, IACS value of 100% (the international standard annealed copper standard values) , high purity (99.996%) and industrial pure aluminum (99.5%) of the IACS is 64.94% and 59%, that of copper conductive than aluminum and about a 35% to 40%; copper chemical stability in the atmosphere over Good, aluminum is more active, but adding trace alloying elements to improve their chemical stability; good strength and hardness of the copper, aluminum somewhat less, but the alloy after heat treatment can obtain higher strength and hardness, due to light, its intensity is much larger than copper; copper resources are relatively limited in nature, higher prices, aluminum resources are relatively abundant and inexpensive.
Same structure and other current busbar copper conductor and aluminum conductor power loss comparison: copper conductor (electrical copper bus TMY, GB5585.1 ~ 3-1985) resistivity ρCU (20) = 0.0175Ω·mm2/m ( When the ambient temperature was 20 ℃ DC resistivity); aluminum conductor (electrical aluminum busbar LMY, GB5585.1 ~ 3-1985) resistivity ρAL (20) = 0.0295Ω·mm2/m(ambient temperature was at 20 ℃ DC resistivity ); conductor ampacity in accordance with relevant comparison of the data analysis, it can be seen with the current aluminum conductors than copper conductors Busway Busway about large power loss 26%, this is the aluminum conductor busbar shortcomings, from the above equation to solve this problem The easiest way is to increase the aluminum conductor cross-sectional area; Click ratio selection designed to allow the aluminum and copper conductor busbar busbar conductors with equivalent conductivity.
Equivalent conductivity copper conductor cross-section aluminum conductors Busway Busway and general economic analysis shows that only from the busbar conductor material cost analysis, the equivalent conductivity of aluminum and copper conductor busbar conductor busbar, the former only for the latter about 1/5. Because aluminum conductor busbar in the manufacturing process of the specific process, the manufacturing cost is relatively high, the analysis shows comparison between the two is about 2.5:1. Comprehensive above comparison, can be considered an aluminum conductor busbar has a high cost, has great application value products.
Economic activity in the current market, the increase in market share and competitiveness of enterprises is the pursuit of the goal of all businesses, the majority of Busway and medium-sized manufacturers especially some brands will bring economic advantages to the product cost benefit the majority of users, in order to save a lot of the majority of construction investment, while saving a lot of valuable resources for the community, to build a conservation of the mainstream of society and make its due contribution to the economy. Therefore, economical and suitable aluminum conductors Busway Busway will bring a revolution in the industry, and to promote a new round of development Busway industry.