Bus duct should always be placed on the floor horizontally and, wooden battens or forms are placed underneath the busduct. Duct board products are available with coated or faced airstream surfaces. Less costly than bus duct entry termination box must have bus risers provides all cable termination hardware provision. Advances in cable technologies, as well as the expense of repairing sensitive cable materials like fiber optic. Hvac load calculation check least based on the airah handbook. Bus bars are thick metal connectors, usually of aluminium, whichcarry. The standard produces fault current results for an unloaded network, that is the results do not include load current and the prefault. In particular, the characteristics of a pair of busbars, and the use of the. 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.
Formoplastic range of bus ducts features our range of bus ducts optional features aconventional non segregated phase bus ducts. Knowing required ampacity, determine possible bus bar dimensions from the table. Download bus duct voltage drop calculation pdf free. These are hollow because flow of the high current exhibits small amount of current passing through the middle of conductor due to skin effect. Nonsegregated phase bus duct technical data td01702001e effective. Isolated phase bus ducts systems are vital components in power plants that are often overlooked. Calculate size of bus bar having following details bus bar current details. Abus duct system is an effective method of distributing power to your. This method is based on the partial inductance theory. You can then calculate bus bar rating based on the total connected load supplied by the bus bar and rate you bus. There is a gener al application section that applies to all types.
Calculation of temperature rise in gas insulated busbar by coupled magnetothermalfluid analysis article in journal of electrical engineering and technology 44 december 2009 with 184 reads. Busbars may be enclosed in a metal housing, in the form of bus duct or busway, segregatedphase bus, or isolatedphase bus. And the enclosure size is where the cable bus advantage begins to pull away from the pack, where the maximum size for cable bus, so far, has been 26 inches wide by 12 inches high. These products permit rigorous cleaning of the duct surface where dust has been allowed to collect in the duct due to lack of. Bus duct comparison of the two technologies bus duct is defined in the nec 368. Recommended practices for designing and installing copper building wire systems cda cwis committee december 3, 20 developed by the. The bus duct is designed, manufactured, and tested in accordance with ansiieee standard c37. Rated voltage 415v,50hz, desire maximum current rating of bus bar 630amp.
Copper or aluminum is used for the conductor of bus duct that be insulated and enclosed completely for protection against mechanical damage and dust accumulation. Powell is the premier designer and manufacturer of isolated phase bus, nonsegregated and segregated phase bus, cable bus and bus accessories in the united states. A simplified method of calculating busbar inductance and. A numerical method for current density determination in threephase. Recommended practices for designing and installing copper. You need to determine the faul level of the systems and full load current from the customer to determine the cb rating. Lowvelocity ductwork design is very important for energy efficiency in air distribution systems. For use as drop cable from overhead bus duct to floor machines. Standards and applications of medium voltage bus duct. There may be an additional voltage drop due to the inductance of the bar. Flexible duct work must be stretched tightly for maximum air flow. During the installation, inspect the bus bar run for straightness in all planes and make any adjustment necessary for good alignment. This plate bolts into the same bolt holes used for the bus duct entrance termination box and can be installed locally so that the transformer can be reused without sending it to emeryville to have the opening covered code 180203.
Bus drop cable pvc insulation pvc jacket applications. Highvelocity hv duct systems are characterized by air velocities in the range of 2500 to 3500 fpm. Refurbishment of isolated phase bus that was damaged by others prior to installation. Air flow problems have plagued the hvac industry for years. Always stagger takeoff ducts by 12 to maintain pressure. Air duct calculator duct velocity duct airflow fpm cfm duct diameter round inches of water inches friction loss per 100 of duct flexible duct friction loss calculator sheet metal duct friction loss calculator duct diameter approximate dynamic loss coefficients duct length feet friction loss 2. Weight calculator standard conversion factors inch 25.
Ge industrial solutions metal enclosed nonsegregated bus duct. Installed quickly without use of conduit for fixed or temporary power. Terminations less costly than bus duct entry provision. Free spreadsheet for hvac systems heating and cooling load estimation. Busduct is a sheet metal duct with aluminium or copper bus bars, and used as a reliable link for transferring power from one equipment to other at desired voltage levels. Three phase highcurrent bus duct of rectangular cross. Abus duct system is an effective method of distributing power to your switchgear and various loads. Duct and conduit 473 chapter 14 duct and conduit introduction the general purpose of conduit, or duct, is to provide a clear, protected pathway for a cable, or for smaller conduits, sometimes called. Rao chp 8 design of bus bars brief notes and practice examples for bus bar. It is used as an alternate means for conducting electricity to cable bus and power cables. Calculation of temperature rise in gas insulated busbar by. Ive run a 3 phase short circuit study but i have protective devices in my tcc drawing that still have isc amps of 200,000a.
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. A cover used to close off the bus duct entrance hole left in a transformer when it is removed or replaced. When sizing busbars the designer only needs to make calcu. Ge industrial solutions metal enclosed nonsegregated bus. Duct design quick introduction duct sizing tools and methods recommended duct velocities and noise effects. Eliminates any faults caused by moisture in the bus duct protect your bus duct systems and your staff with a retrofitted dry air condensation control system from azz to effectively prevent condensation and ensure safe, reliable bus system operation. Enter duct airflow cfm, duct velocity fpm, duct length and the number of bends.
Hvac cooling load calculations and principles sensible heat gain is the energy added to the space by conduction, convection andor radiation. It is an alternative means of conducting electricity to power cables or cable bus. 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. Inthe power stations the generator voltages vary from 12 kv to 24kv whereas auxiliary supply voltages are 3. Bus ductsintroductionbus ducts or bus bars are used to carry very high current betweenthe generator and associated transformers, in the.
Abb low voltage and medium voltage busducts are safe, compact, flexible, reliable and efficient solutions for electrical power distribution. Use insulated duct or duct board in unheated spaces. Duct and conduit 473 chapter 14 duct and conduit introduction the general purpose of conduit, or duct, is to provide a clear, protected pathway for a cable, or for smaller conduits, sometimes called innerducts. These limits should not be used for cables subjected to pulling tensions during installation. Calculate the pressure loss of the duct fitting in a 600mm w x 200mm h duct. We are ready to custom engineer your utility, cogeneration, petrochemical or heavy industrial application with a complete range of bus duct products, systems and services. Rating 415v, 50hz ranging from 3200 amps to 5000 amps csegregated phase bus duct. In electric power distribution, a bus duct also called busway, is a sheet metal duct containing either copper or aluminium busbars for the purpose of conducting a substantial current of electricity.
Download ashrae heat load calculation excel sheet xls. Mdy busduct system a reliable and safe solution for power. Sizing busbars the busbar constitutes the real backbone of any distribution assembly. With magicads automated design tools, even demanding duct routing solutions are easy to make. The file contains 121 pages and is free to view, download or print. Busbars may be enclosed in a metal housing, in the form of bus duct or. Labor cost installation labor costs for bus duct systems can be less than labor costs for cable bus. Installation of delta unibus isolated phase bus duct system. Pdf in this paper, a 3d eddycurrent field model for calculating the eddy current losses in an air insulated bus duct system aibds is. Apr 03, 2016 readbag users suggest that qatarkahramaaregulations. And for a comparable rated bus duct, that size is usually up to 36 inches by 18.
The purpose of this chapter is to provide technical data on numerous bus conductor shapes and alloys as well as answers to basic questions on design and joining. Method of statement for installation of power busbar method. Put your presentation title or confidentiality info here. Thus, by using the above formula and table, we can easily select. Unit 1 and unit 2 isolated phase bus duct welding and installation. Power cable installation guide figure f5 multiple sheaves figure f6 sheave arrangements for feeding into cable tray training radius the training radius is the final positioning of cable ends after the cable has been placed in the raceway. Refer to uangyihtech flanges system section for adapters, drains and test port aw end available. Calculating bus duct voltage drop mike holts forum. Condensation control for bus duct controlling moisture to maintain optimal bus.
Tables 4 and 5 summarize the estimated values for two. Table gives bus bar cross section which will probably be large enough for ampacities within each range. Ge industrial solutions metal enclosed nonsegregated bus duct description nonsegregated phase bus duct is designed for interconnecting groups of metalenclosed or metal clad switchgear, power transformers or other related equipment. Never locate ducts at the end of the trunk line run. Cable bus systems are also very competitive to 600 volt bus duct systems as well. This document was uploaded by user and they confirmed that they have the permission to share it. Read round duct diameter inches and friction loss per 100 of duct. Easily disconnected and connected when machines are moved. Pdf recent progresses in busducts design researchgate. Heat conduction and thermal resistance for steady state conditions and one dimensional heat transfer, the heat q. Home technical articles standards and applications of medium voltage bus duct bus duct is used for the effective and efficient supply of electricity in mostly industrial locations. Resistant to oil, grease, acids, cutting fluids and mechanical abuse. Flow of air is caused as a result of pressure differential between two points. Lowvelocity design will lead to larger duct sizes, but it may be worth since, doubling of duct diameter.
These isophase bus duct systems are the only critical components within the plant that have no redundancy and no quick replacement solutions. Recent progresses in busducts design article pdf available in compel international journal of computations and mathematics in electrical 351. Why dont they pickup the calculated bus fault current. Download free mep calculation excel sheets, autocad drawings, and. Busbars may be connected to each other and to electrical apparatus by bolted, clamp, or welded connections. Paying attention to certain details of bus duct projects will ensure troublefree service. Rating 415v, 50hz ranging from 800 amps to 3200 amps blow reactance interleaved bus ducts.
Calculation of induced current in bus duct shell is a fundamental problem in determining the exact bus duct losses, and it needs an accurate analysis of the plan, and to determine it, it is possible to use. One disadvantage to locating the air handler in the attic. Ebus duct rated 49 ka rms symmetrical 2 seconds 1 all phase conductors above 635 v are fully insulated with epoxy insulation for the rated maximum voltage. And cables in tray, if you go up to 5,000 amps, you will end up with multiple tray runs. You should be able to get the voltage drop information from the bus duct manufacturer, or would would need to know the area and material of the bus to do your own calculation. Ventilation systems design and calculations air renewal rates for premises in general recommended number of renewalshour, depending on the type of premises din 1946 standard. Bus ductsintroductionbus ducts or bus bars are used to carry very high current betweenthe generator and associated transformers, in the power stations. More costly than cabl bus, to within 8 on top of cell or the duct including lugs and stress cone more cables to terminate. Cable tray, cable bus, wire mesh cable trays mp husky. Busduct is a system of distributing electric power using copper or aluminium busbars with.
219 524 196 13 1493 147 996 807 1365 391 299 38 829 403 542 270 350 121 447 679 377 563 333 1301 1490 1159 1537 1090 984 1358 877 138 1155 1040 466 102 802 771 49 1294 231 1214 123 682 952 1393 850 198 402