Bus ducts are a new type of circuit developed in the United States and called the “Bus-Way-System”, which is a new type of conductor formed by using copper or aluminum as a conductor, supporting it with nonalkaline insulation, and installing it in a metal tank. The actual application of bus ducts in Japan began in 1954, the 29th year of the Showa era, and bus ducts have been developed ever since. Today in high-rise buildings, factories and other electrical equipment, power systems have become indispensable wiring.
Introduction
With the emergence of modern engineering facilities and equipment, all walks of life of the rapid increase in electricity consumption, especially the emergence of many high-rise buildings and large-scale factories and workshops, as the transmission conductor of the traditional cable in the high-current transmission system has been unable to meet the requirements of the parallel use of multiple cables to the site of the installation and construction of the connection has brought about a lot of inconvenience. Plug-in bus ducts as a new type of power distribution conductor should be born, compared with the traditional cable, in the high-current transmission fully reflects its superiority, while due to the use of new technologies, new techniques, greatly reducing the bus ducts at the two ends of the joints and the splitter port plugging at the contact resistance and temperature rise, and the use of high-quality insulating materials in the bus ducts, which improves the safety and reliability of the bus ducts to make the whole system more perfect.
Characteristics
Bus duct is characterized by series matching, commercial production, small volume, large capacity, short design and construction cycle, easy to install and dismantle, will not burn, safe and reliable, long service life. Bus duct products are suitable for AC 50Hz, rated voltage 380V, rated current 250A-6300A three-phase four-wire, three-phase five-wire power supply and distribution system engineering.
Superiority
Enclosed bus duct seal (referred to as bus duct) is made of metal plate (steel or aluminum plate) for the protective shell, conductive rows, insulating materials and related accessories composed of busbar system. It can be made every distance with plug-in junction box plug-in closed bus, can also be made in the middle without junction box feeder-type closed bus. In high-rise buildings in the power supply system, power and lighting lines are often set up separately, bus ducts as the main power supply in the electrical shaft along the wall vertical installation of a trip or more trips. According to the use of a busway generally by the beginning of the busway, through the busway (with jacks and without two kinds of jacks), L-type vertical (horizontal) curved through the busway, Z-type vertical (horizontal) offset busway, T-type vertical (horizontal) tee busway, X-type vertical (horizontal) tee busway, capacitor busway, expanding busway, terminal header, terminal terminal junction box, plug-in box, busway accessories and fastening devices and so on. The bus ducts can be divided into three types according to the insulation method. Busway according to the insulation can be divided into air-type splicing busway, dense insulation splicing busway and high-strength splicing busway three. According to its structure and use is divided into dense insulation, air insulation, air-attached insulation, fire-resistant, resin insulation and sliding busway; according to its shell material is divided into steel shell, aluminum alloy shell and steel and aluminum mixed shell busway.
Classification
According to the use, the busway is generally by the beginning of the busway, through the busway (with jacks and without two kinds of jacks), L-type vertical (horizontal) curved through the busway, Z-type vertical (horizontal) offset busway, T-type vertical (horizontal) tee busway, X-type vertical (horizontal) tee busway, capacitor busway, expanding busway, terminal header, terminal terminal junction box, plug-in box, busway accessories and fastening devices, and other components. The busway is composed of the following.
According to the insulation method, can be divided into air type splicing busway, dense insulation splicing busway and high strength splicing busway three.
Air-type splicing busway (BMC). Due to the transition between the joints of the busbar with a copper soft joint, in the south of the humid weather, between the joints are prone to oxidation, the formation of joints and busbar contact is poor, so that the contacts are prone to heat, so in the south is rarely used. And the volume between the joints is too large, the horizontal busbar section size is inconsistent, the appearance is not beautiful.
Dense insulated plug-in busway (CMC). Its moisture-proof and heat dissipation effect is poor. In terms of moisture protection, the busbar is susceptible to moisture and water seepage during construction, resulting in a drop in insulation resistance between phases. The heat dissipation of the busbar mainly relies on the shell, due to the compact arrangement and installation between the line and the line, the L2 and L3 phases are slow to emit heat energy, resulting in a high temperature rise of the busway. Dense insulated plug busway is limited by the shell plate, can only produce not more than 3m horizontal section. Due to the small air gap between the busbar phases, when the busbar passes a large current, it generates a strong electromotive force, which forms a superposition of the magnetic oscillation frequency, resulting in excessive noise.
High strength closed busway (CFW). The process of manufacturing is not limited by the plate, the shell is made into a tile groove form, so that the mechanical strength of the bus increases, the horizontal section of the bus can be produced up to 13m long. As the shell made of tile groove form, pit groove position intentionally separated from the busbar fixed, 18mm spacing between the busbar, good ventilation between the lines, so that the busbar sink moisture and heat dissipation function has significantly improved, more adapted to the southern climate; due to the gap between the lines, so that the temperature rise of the conductor down, so as to improve the overload capacity, and reduce the noise of magnetic oscillations. But it produces stray currents and inductive impedance is much larger than the dense busway, so in the same specification comparison, its conductive row cross-section must be larger than the dense insulated plug-in busway. Plug-in busway is a trunking system, with small size, compact structure, reliable operation, large transmission current, easy to tap feeder, easy maintenance, small energy consumption, good dynamic and thermal stability, etc., in high-rise buildings are widely used.
