INDAL Busbar DetailsDimension of Al. Bus barTotal Cross Section Per Phase ( sq. mm)AC Current at an ambient of 35 deg & rise 50 deg.Correction FactorDerated current considering correction factor as .667Width (mm)Thickness (mm)No. of barsNo. of bars0.667No. of bars12341234123425.46.35161.29322.58483.87645.1635570597011000.667236.785470.235646.99733.738.16.35241.94483.87725.81967.745201020135015350.667346.84680.34900.451023.84550.86.35322.58645.16967.741290.326701290170519400.667446.89860.431137.2351293.9863.56.35403.23806.451209.681612.908101510200022600.667540.271007.1713341507.4276.26.35483.87967.741451.611935.489601740231026200.667640.321160.581540.771747.54101.66.35645.161290.321935.482580.6412352140280032000.667823.7451427.381867.62134.41276.35806.451612.902419.353225.8015052510324037000.6671003.8351674.172161.082467.9152.46.35967.741935.482903.223870.9617802860368042400.6671187.261907.622454.562828.0850.89.53484.12968.251452.371936.508301500197022600.667553.611000.51313.991507.4276.29.53726.191452.372178.562904.7411802050266030300.667787.061367.351774.222021.01101.69.53968.251936.502904.743872.9914952480315035600.667997.1651654.162101.052374.521279.531210.312420.623630.934841.2418602930366042000.6671240.621954.312441.222801.4152.49.531452.372904.744357.125809.4921203340408046800.6671414.042227.782721.363121.56203.29.531936.503872.995809.497745.9827504150490057400.6671834.252768.053268.33828.5876.212.7967.741935.482903.223870.9613552240283032400.667903.7851494.081887.612161.08101.612.71290.322580.643870.965161.2817402720336039000.6671160.581814.242241.122601.312712.71612.903225.804838.706451.6020803120390045500.6671387.362081.042601.33034.85152.412.71935.483870.965806.447741.9224203500440051000.6671614.142334.52934.83401.7203.212.72580.645161.287741.9210322.5630604450530061500.6672041.022968.153535.14102.0525412.73225.806451.609677.4012903.2036405000600068500.6672427.88333540024568.95Dimension of each of droppersTotal Cross Section Per PhaseTotal Cross Section Per PhaseTotal Cross Section Per PhaseTotal Cross Section Per PhaseAC Current at an amb of 35 degWidthThickness25.46.350.000.000.000.0097038.16.350.000.000.000.00135050.86.350.000.000.000.00170563.56.350.000.000.000.00200076.26.350.000.000.000.002310101.66.350.000.000.000.0028001276.350.000.000.000.003240152.46.350.000.000.000.00368050.89.530.000.000.000.00197076.29.530.000.000.000.002660101.69.530.000.000.000.0031501279.530.000.000.000.003660152.49.530.000.000.000.004080203.29.530.000.000.000.00490076.212.70.000.000.000.002830101.612.70.000.000.000.00336012712.70.000.000.000.003900152.412.70.000.000.000.004400203.212.70.000.000.000.00530025412.70.000.000.000.006000Dimension of each of droppersTotal Cross Section Per PhaseTotal Cross Section Per PhaseTotal Cross Section Per PhaseTotal Cross Section Per PhaseAC Current at an amb of 35 degWidthThickness25.46.350.000.000.000.00110038.16.350.000.000.000.00153550.86.350.000.000.000.00194063.56.350.000.000.000.00226076.26.350.000.000.000.002620101.66.350.000.000.000.0032001276.350.000.000.000.003700152.46.350.000.000.000.00424050.89.530.000.000.000.00226076.29.530.000.000.000.003030101.69.530.000.000.000.0035601279.530.000.000.000.004200152.49.530.000.000.000.004680203.29.530.000.000.000.00574076.212.70.000.000.000.003240101.612.70.000.000.000.00390012712.70.000.000.000.004550152.412.70.000.000.000.005100203.212.70.000.000.000.00615025412.70.000.000.000.006850

&C&"Arial,Bold"&14INDAL CHART

2x50x10CALCULATION OF ALUMINIUM dropper for 800APARAMETERSFeeder Rating800ASize of Aluminium Bus Bar considered2x50x10mm2i.e.Runs/Phase2mmCurrentWidth50mmThickness10mmfor EIE-M grade (Amp)Current rating as per INDAL Aluminium ( E91)=0.97*EIE M grade current1455A1500Afor EIE gradeDesign Ambient Temperature50oCRise in Temperature allowed40oCFinal Temperature Permitted90oCSize of Bus Bar enclosure175 x 800sq.mmi.e.Height175mmDepth800mmFault current (for 1 sec)50000ADuration of Fault1sGrade of Al. dropperE91-EA.MINIMUM CONDUCTOR SIZE Area of cross sectionFormula to determine the minimum size of conductor for any fault level:t =(k/100) x ( Isc/A)2 x (1+ 20 . ) x t( Ref: Industrial Power Engineering and Application Handbook, Page 865)t=temperature rise above operating temp. in deg. C100oC(190-90)oC95oC(185-90)oCIsc=symmetrical fault current in r.m.s in Amps.A=cross sectional area of conductor in mm220=temperature coefficient of resistence at 20 deg C/deg C0.00403for pure Aluminium0.00363for Aluminium alloy0.00393for pure copper=operating temperature of the conductor at which the fault occursk=1.166for aluminium0.52for coppert=duration of fault in secondsAluminium starts softening at a temperature of around 180-200 deg.As a rule of thumb forAl conductor,on a fault a safe temperature rise of 100 deg above the allowable end temperatureof 90 deg of the conductor during normal condition has been considered & taken as the basisto determine the minimum size of the conductorFinal temp. allowed for busbar after short circuit is 190 deg CBy putting all values in the above equation100 =(1.166/100) ( 50000/A)2 (1+ 0.00363 x 90) x 1A=630.26sq.mmfor pure Al.( final temp 190 i.e. 90+100)621.88sq.mmfor Al alloy( final temp 190 i.e. 90+100)646.63sq.mmfor pure Al.( final temp 185 i.e. 90+95)638.03sq.mmfor Al alloy( final temp 185 i.e. 90+95)B.THERMAL RATINGI.DERATING FACTOR ON ACCOUNT OF HIGHER AMBIENTTEMPERATUREDesign Ambient Temperature50oCOperating temperature 90 deg COperating temperature 85 deg CRise in Temperature allowed40oCAmbient tempPermissible Bar temp riseDerating FactorAmbient tempPermissible Bar temp riseDerating FactorDerating Factor k1 :0.88oCoCoCoC( Ref: Industrial Power Engineering and Application Handbook, Page 870,871)35551.0530551.054050135501II.DERATING DUE TO ENCLOSURE45450.94540450.94550400.8845400.88Cross sectional area of busbar=No. of Phase x (Cross Section per Phase) x 10055350.81550350.815cross sectional area of enclosurecross sectional area of enclosure60300.7555300.75=300000=2.1428571429140000Derating Factor due to enclosureAs per table 5(enclosed) of INDAL paper on INDAL Al. Bus Bar,EnclosureRatioDerating Factorthe derating factor, k2 :0.75if ratio is less than 5%1.Outdoor