The main bus and its enclosure is normally in a tubular form, in view of the inherent advantages of a tubular figure 31. Pdf calculation of maximum short circuit electromagnetic. Compared to traditional fourpiece structures, the twopiece structure design of the pmax system reduces the temperature rise of the enclosure. For example, complete power distribution subsystems can also act as structural members of a total system. Pdf recent progresses in busducts design researchgate. Carefully study this instruction manual and other documents attached hereto before. Enter duct airflow cfm, duct velocity fpm, duct length and the number of bends. State the safety regulations associated with sheet metal and fiberglass duct. Read round duct diameter inches and friction loss per 100 of duct inches of water.
Energy conserving and energy star listed equipment should be used as the design basis for all facilities. This approach also helps to minimize the number of floor penetrations. Spectra and spectra ii series plugin and feeder busway. Busbars may be connected to each other and to electrical apparatus by bolted, clamp, or welded connections. Plus, the physical structure of bus bars offers unique features in mechanical design. Tap bar bus duct in case of current branching over 400 a plugin bus duct is indoor type only. In this paper, the impact rate of bus duct was identified and the induced current of every phase shell was calculated separately with different bus duct designing. The total fault current, must be used for breaker and switchgear sizing. Short circuit current calculations cooper industries. Installation prices for busbars, cables and cable ducts are calculated as the average of prices provided by several major companies dealing in wiring installations. Developed between bus bars due to short circuit current. Calculation of temperature rise in gas insulated busbar by.
Knowing required ampacity, determine possible bus bar dimensions from the table. They may be of the open type, such as to feed a very high current at. Spectra and spectra ii series plugin and feeder busway installing spectra series busway 4 obstructions where a busway run must pass through a wall. Design calculations establish minimum guidelines and requirements for generating electrical calculations on projects. Then check previous table to verify that size selected has the. Cable bus systems are also very competitive to 600 volt bus duct systems as well. Electrical calculations should be made for all spu projects that include electrical components and should be filed in the project notebook. They may be of the open type, such as to feed a very high current at very low voltage. While this methodology doesnt have any relation with calculation of conductor bus sizing acsr for the switch yard projects. Maintenance intensive components such as bus duct, battery systems, fancooled equipment, etc. When sizing busbars the designer only needs to make calcu. Labor cost installation labor costs for bus duct systems can be less than labor costs for cable bus depending on the particular installation.
These products permit rigorous cleaning of the duct surface where dust has been allowed to collect in the duct due to lack of filtration or poor maintenance. Shortcircuit current calculations cooper industries. Online ductulator ocean hvac, manualj load calculator. The shorter the duct runs are, the lower the resistance to air flow and the lower the heat gains and heat losses will be. Lowvelocity design will lead to larger duct sizes, but it may be worth since, doubling of duct. This bulletin is an update and revision of previous rea bulletin 651, design guide for rural substations revised june 1978. There is a basic fitting to meet every application need and products are designed to provide an economical system, yet meet the specifications which are the most important. In mounting the branch devices, the tap bar of the bus duct side and the conductor in the device are clamped by bolts.
Recent progresses in busducts design article pdf available in compel international journal of computations and mathematics in electrical 351. Pdf calculations of eddy current, fluid, and thermal fields in an. Paying attention to certain details of bus duct projects will ensure troublefree service. Design calculations may be made either manually or by spuapproved computer programs. Rooms are to be designed to allow growth within the electrical system and safe.
Determine the rating, location and quantity of branch units and calculate the. Heat conduction and thermal resistance for steady state conditions and one dimensional heat transfer, the heat q conducted through a plane wall is given by. There may be an additional voltage drop due to the inductance of the bar. One disadvantage to locating the air handler in the attic space is serviceability. Busbars may be enclosed in a metal housing, in the form of bus duct or busway, segregatedphase bus, or isolatedphase bus. Using busway in place of cable and conduit to distribute electrical power can help building owners save all three commodities in significant amounts. Abus duct system is an effective method of distributing power to your switchgear and various loads.
You need to determine the faul level of the systems and full load current from the customer to determine the cb rating. Scribd is the worlds largest social reading and publishing site. Calculation of maximum short circuit electromagnetic forces is one of the most important factors in the mechanical design and optimization of isolated phase buses which is required by the. In case of current branching over 400 a, a tap bar bus duct attached with tap bars, shown in the photo on the left, shall be used. Chapter layout and fabrication of sheet metal and. Bus bars reduce system costs, improve reliability, increase capacitance, and eliminate wiring errors. Duct board products are available with coated or faced airstream surfaces. Lowvelocity ductwork design is very important for energy efficiency in air distribution systems. Highvelocity hv duct systems are characterized by air velocities in the range of 2500 to 3500 fpm.
This manual will be divided into several sections each section pertaining to a specific line of bus duct com plete with all of the dimensions, voltage drop curves, and characteristics. Put your presentation title or confidentiality info here. Pdf in this paper, a 3d eddycurrent field model for calculating the eddy current losses in an air insulated bus duct system aibds is. Calculate size of bus bar having following details bus bar current details. Busduct eaton busduct provides flexible power distribution solutions for a variety of applications where change and adaptation are important. Chapter layout and fabrication of sheet metal and fiberglass duct topics. Introduction mp husky cable bus systems are engineered and manufactured for superior reliability as well as to utilize less conductive material, providing signi cant savings versus nonsegregated phase bus duct, conduit and wire, and other electrical feeders. Busbars are quoted as if they refer to an offer for an end user of average importance for building a mediumsize system. Busduct is a system of distributing electric power using copper or aluminium busbars with. Rated voltage 415v,50hz, desire maximum current rating of bus bar 630amp. Layout and fabrication of sheet metal and fiberglass duct welding quality control. A practical estimate of motor short circuit contribution is to multiply the total motor current in amps by 4. You can then calculate bus bar rating based on the total connected load supplied by the bus bar and rate you bus bar based on percentages of full load current of connected load. Calculation of air volume to exhaust correction factors according to the type of installation chart 2 type of installation multiplication factor wallmounted hood 1.
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