Pow-R-Way III Busway Design Guide - Eaton

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIGeneral DescriptionConstruction DetailsSee Figure 24.1-3Bus bars are fabricated from high strength, 99% conductivitycopper or 57% conductivity aluminum. The joint edge of eachbusway conductor bar is beveled while the Pow-R-Bridgeconductor bars have full rounded edges. This makes for a smoothand easy connection between the busway and Pow-R-Bridgejoint. The phase and neutral bars are insulated with Class B 130 Cepoxy insulation. The epoxy powder is applied by an automatedfluidized bed process to ensure uniform thickness. The epoxypowder is applied over the full length of the preheated bar exceptfor the joint and plug-in contact surfaces. After the powder hasbeen fused to the bus bar, the bars enter an oven to cure. Thisprocess ensures that all of the epoxy powder cross links andhardens to the bus bar.Fluidized bed applied epoxy provides resistance to waterabsorption and chemical erosion. Epoxy has outstanding heattransfer characteristics and is ideally suited for sandwich busapplications. The uniform thickness and smooth surface providedby epoxy ensures that the insulation will have no cavities orvoids and also provides excellent edge coverage to the bars.Epoxy has excellent dielectric strength, is flame retardant andresists impacts that other Class B insulating material couldnot withstand.Bus bars for plug-in applications have full-sized weldedconductor tabs at the contact location points of the plug-in outlet.The tabs are of the same thickness as the conductor bars. Theplug-in conductor tabs extend into the plug-in outlet, maintaininga true sandwich design throughout the entire busway length.Effective February 202024.1-3Integral GroundThe two-piece, extruded aluminum housing is designed,manufactured and UL listed as a 50% integral ground path(integral earth) and is fully fault rated. The system groundcontinuity is maintained through each joint by the ground pathend blocks, ground path plates and joint covers. The aluminumjoint covers are furnished with ground path contact surfaces onthe inside of each end. When the covers are installed, the contactsurfaces are bolted directly to the ground path end blocks withfour 3/8-16 1/2-inch (12.7 mm) hex bolts per cover.A highly visible label is furnished on each joint cover to alert theinstaller that the covers must be properly installed to maintainthe ground path. The result is a 50% ground path that ensuresground continuity with very low resistance characteristics.Internal Ground OptionPow-R-Way III offers a 50% ground bus (copper or aluminum)that is internal to the busway.Isolated Ground OptionTo meet the growing demand for grounding isolation, Pow-RWay III offers a 50% isolated ground bus that is insulated andinternal to the busway. This option is available for applicationto operations with heavy microprocessor-based loads or largecomputer installations where grounding isolation is essential.The result is improved heat dissipation, better bracing andelimination of the need to separate, or flare, the conductor barsat the plug-in opening. Maintaining a true sandwich design alsoeliminates potential pathways for the propagation of flame,smoke and gas through the busway housing, commonly referredto as the “chimney effect.”Silver-plating is applied to all joint and contact surfaces afterthe fluidized bed epoxy is applied. Aluminum bus bars aresilver-plated by the AlstanT 88C process. Copper bus bars areplated with silver by a flashing process. The silver-plating of theconductor tabs provides an extremely durable contact surfacefor the spring loaded connections of bus plug stab assemblies.Housing DetailsSee Figure 24.1-3Pow-R-Way III is constructed with a rugged two-piece extrudedaluminum housing. There are no seams or welds across the topor bottom sides of the housing. The housing is bolted along thebottom sides below the bus bars with high tensile strengthzinc-plated hardware. No fastening bolts or screws penetratethe housing or enter the bus bar package.Figure 24.1-3. Housing AssemblyPow-R-Way III achieves the highest 6-cycle short-circuit withstandratings available in the industry today.The non-magnetic, allaluminum housing provides for excellent heat dissipation and asignificant reduction in reactance and magnetic flux leakage ascompared to a steel or steel and aluminum combination housing.The integrity and strength of the housing ensures specifiers andusers of a safe and durable installation over a broad spectrum ofindustrial and commercial applications.A protective finish of ANSI 61, epoxy powder paint is applied byan automated electrostatic process.EATON www.eaton.com

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIGeneral DescriptionEffective February 202024.1-4200% Neutral OptionUL Fire Stop SystemSee Figure 24.1-4Pow-R-Way III busway may be used in UL listed throughpenetration fire stop systems. Systems applicable to busway(i.e., system number C-AJ-6002) are listed in the UL FireResistance Directory under “Through-Penetration Fire StopSystems” and have met the ASTEM E814 (UL 1479) criteria.Power System Harmonics are generated by various types ofnonlinear loads. A sinusoidal voltage applied to a nonlinear loadwill result in a non-sinusoidal current and waveform distortion.Loads that are switched or pulsed, such as rectifiers, thyristors andswitch-mode power supplies, are nonlinear. With the proliferationof electronics into industrial, commercial and institutionalapplications, nonlinear loads have become a significant andcritical component of most modern distribution and controlsystems. Examples of nonlinear loads are personal computers,UPS systems, variable frequency motor controllers, electroniclighting ballasts, fax and copying machines, medical testequipment and many other microprocessor-based apparatus.Nonlinear load currents typically are extremely high in harmoniccontent. The harmonics create numerous problems in electricalsystems and equipment. Some harmonics are negative sequencewith 120 phase displacement (this means the phase rotationis ACB instead of ABC). Positive sequence harmonics have120 phase displacement, but are of the same rotation as thedistribution system. Certain nonlinear loads cause odd triplenharmonics which are zero sequence with no phase displacement.Balancing the phase load currents in a three-phase, four-wiresystem will normally reduce neutral currents to zero if loadcurrents have an undistorted sinusoidal waveform. However,because zero sequence harmonics are additive and will notcancel each other in the neutral, the neutral current can be ashigh as 1.73 times the phase current, even with the phasecurrents perfectly balanced. This can result in overheatedneutrals and lead to deterioration of equipment performanceand a shortened equipment life cycle.For typical installations shown in Figure 24.1-5, the installingcontractor uses mineral wool batt and fire stop sealant. In riserapplications, the system is used in combination with Pow-R-WayIII vertical spring hangers and a floor flange. In horizontalapplications, the system is used in combination with two wallflanges, one on each side of the wall, and sealant.Note: This information is provided as a guideline for typical fire stopsystems. Consult the fire stop system sealant manufacturer for the UL filenumber and specific product information.UL Listed Pow-R-Way IIIBuswayVerticalHangerMounting Support(by Others)Floor Flange12 Ga SteelTPow-R-Way III offers a fully rated, 200% neutral bus optionfor busway fed distribution systems with nonlinear loads. Theadditional neutral capacity prevents the overheating causedby zero sequence harmonic currents. The Pow-R-Way III 200%neutral is manufactured with a single 0.50-inch (12.7 mm) thickbus bar, which receives the same silver-plating and Class B,130 C Epoxy insulation as the phase bars.FloorFirestop MaterialSuggest 3m, SpecifiedTechnologies, or EquivalentManufacturer Fire Stop Products—UL 1479 ListedFloor Flange (Optional)Figure 24.1-5. Typical Installations of Pow-R-Way III in Fire Stop SystemsThe Computer and Business Equipment ManufacturersAssociation (CBEMA) recommends that neutrals be oversized toat least 173% of the ampacity of the phase conductors to preventproblems. Pow-R-Way III offers a fully rated, 200% neutral busoption for busway fed distribution systems with non-sinusoidalloads. The additional neutral capacity prevents the overheatingcaused by high harmonic neutral currents.Pow-R-Way III, Three-Phase Four-Wirewith Housing Ground and 200% NeutralTopABCNFigure 24.1-4. 200% Neutral Cross SectionEATON www.eaton.com

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIGeneral DescriptionEffective February 202024.1-5Pow-R-BridgeSee Figure 24.1-6Pow-R-Way III joint connections are made with the Pow-R-Bridgejoint package, which is installed on each section of busway priorto shipment. A double-headed, torque-indicating bolt is providedto ensure that proper installation torque is achieved. Fall-awayinstruction tags are furnished on the torque-indicating bolt headsto allow for visual inspection from a distance. When the propertorque value is achieved, the top bolt head will shear off andallow the tag to fall to the floor. Any joint that is improperlytorqued will retain the highly visible (caution yellow) tag at thebolt head.The Pow-R-Bridge can provide an adjustment of 0.50 inch(12.7 mm) at each joint. Over adjustment is prevented by the jointcovers, which will only allow a 0.50-inch (12.7 mm) adjustmentto be made and by stopping lances on the conductor bars of thePow-R-Bridge. The non-rotating design of the Pow-R-Bridgemaintains its configuration integrity when it has been removedfrom a section of busway. The conductors and insulators will notdisplace or swivel, making reinstallation of the Pow-R-Bridgequick and easy.Outdoor Pow-R-BridgeBellevilleBridge JointPressure Plate Washer(Top & Bottom)Double-headedTorque-IndicatingBolt (Bottom)Ground Path PlateGround PathEnd Block130º EpoxyInsulationon BarsBridge JointRetainer Screw1/4-20 flg.Head Hex Bolt(4 per cover)GroundPath ContactSurface.375-16 flg.Head Hex Bolt(4 per Cover)Joint CoverHigh StrengthGlass PolyesterInsulatorsGround PathEnd BlockGroundPath LabelCaptive NutRetainerFigure 24.1-6. Indoor Bridge Joint FeaturesDrainGasketed Torque – Hole PlugBolt Access Cap(Top & Bottom)Gasketed TopAccess CoverSee Figure 24.1-7Joint connections for outdoor feeder busway are made with aweatherized version of the Pow-R-Bridge joint. Aluminum waterbarriers, 1/16-inch (1.6 mm) thick, are provided across the “T” and“T opposite” sides of both joint ends on each section of outdoorbusway. Closed cell, neoprene gaskets are applied to the top ofeach water barrier and to the inside of the aluminum side accesscovers. The aluminum side access covers overlap the top andbottom access covers and bolt directly onto the end blocks. Theoutdoor Pow-R-Bridge has the same 0.50 inch (12.7 mm)adjustability and features as the indoor unit and is UL listed.GasketedCover Plate(L)BellevilleWasherGroundPath ContactSurfaceGasketedRear JointCoverUL 857IEC 439Figure 24.1-8ConfigurationsWidthLengthInches (mm)Inches (mm)Copper225400600225400630AAA4.50 (114.3)4.50 (114.3)4.50 (114.3)7.38 (187.5)7.38 (187.5)7.38 (187.5)80010001200100012001400AAA4.50 (114.3)5.12 (130.0)5.62 (142.8)7.38 (187.5)7.38 (187.5)7.38 (187.5)135016002000155018002250AAA6.12 (155.4)7.12 (180.9)8.38 (212.9)7.38 (187.5)7.38 (187.5)7.38 (187.5)25003200400050003000380045005800BCCD10.88 (276.4)15.88 (403.4)18.38 (466.9)23.41 (594.6)7.38 (187.5)7.38 (187.5)7.38 (187.5)7.38 (187.5)Water BarrierPressure Plate(Top & Bottom)Ground PathEnd BlockCaptive NutRetainerPow-R-Bridge JointTable 24.1-5. Busway Pow-R-Bridge Joint DimensionsAmpere RatingBridge Joint Retainer ScrewDouble-HeadedJoint Torque BoltGround PathEnd BlockClosed CellNeoprene GasketWater BarrierGasketedCover PlateDrainHole PlugTorque BoltAccess OpeningGasketed BottomAccess CoverFigure 24.1-7. Outdoor Bridge Joint ��——AAA4.50 (114.3)4.50 (114.3)4.50 (114.3)7.38 (187.5)7.38 (187.5)7.38 (187.5)80010001200———AAA5.62 (142.8)6.12 (155.4)7.12 (180.9)7.38 (187.5)7.38 (187.5)7.38 (187.5)135016002000———ABB8.38 (212.9)9.12 (231.6)10.88 (276.4)7.38 (187.5)7.38 (187.5)7.38 (187.5)250032004000———CDD18.38 (466.9)19.88 (505.0)23.41 (594.6)7.38 (187.5)7.38 (187.5)7.38 (187.5)GasketedFront JointCoverGroundPath LabelLFigure AFigure BAL 225 – 1350 AmpereAL 1600 and 2000 AmpereCU 225 – 2000 AmpereCLCU 2500 AmpereCLL/2CLW/2LL/2CLW/2WWFigure DFigure CAL 3200 and 4000 AmpereAL 2500 AmpereCU 5000 AmpereCU 3200 and 4000 AmpereFigure 24.1-8. Pow-R-Bridge JointEATON www.eaton.com

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIGeneral DescriptionEffective February 202024.1-6Pow-R-Way III Feeder BuswaySee Figure 24.1-9 and Table 24.1-6CL225–5000 A copper 225–4000 A aluminumCL TStraight sections of feeder busway can be supplied in any length,at 1/8-inch (3.2 mm) increments, from a 16.00-inch (406.4 mm)minimum to a 10-foot (3048 mm) maximum. Figure 24.1-9illustrates the configuration of feeder busway and Pow-R-Bridgefor the available ampere ratings. See Table 24.1-6 below forreference to the proper configuration.TFFConfiguration A Top View1 Bar Per PhaseCLCLTable 24.1-6. Feeder Busway ConfigurationAmpere RatingUL 857CuIEC 439AlFigure DDFFConfiguration B Top View1 Bar Per PhaseCLCLTConfiguration C Top View F2 Bars Per PhaseCLCLEach section will include one, factory installed, Pow-R-Bridgemounted to the left end of the busway (with the “T” to the top,when viewing the bus from the “F” side). Each Pow-R-Bridge willhave a “T” label that must always match the “T” orientation ofthe busway.TTFConfiguration D Top View2 Bars Per PhaseCLFCL16.00 Minimum(406.4)TFTFFront ViewFigure 24.1-9. Feeder BuswayEATON www.eaton.com

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIGeneral DescriptionEffective February 202024.1-7Pow-R-Way III Plug-in BuswaySee Figure 24.1-10 and Table 24.1-7 and Table 24.1-8 CL225–5000 A copper225–4000 A aluminum12.00(304.8)CL24.00 Spacing(609.6)TStraight sections of plug-in busway are made only in 24.00-inch(609.6 mm) incremental lengths with a maximum length of10 feet (3 m). Figure 24.1-10 depicts the configuration of plug-inbusway and Pow-R-Bridge for the available ampere ratings. SeeTable 24.1-7 below for reference to the proper configuration.CLCLTConfiguration A Top View1 Bar Per PhaseFCL12.00(304.8)12.00(304.8)FCL24.00 Spacing CL12.00(304.8)(609.6)CLTable 24.1-7. ConfigurationAmpere RatingUL 857CuIEC 439AlFigure Configuration B Top View1 Bar Per PhaseFCLT12.00(304.8)CL24.00 Spacing(609.6)TFCLF12.00(304.8)CLCLTFConfiguration C Top View2 Bars Per Phase12.00(304.8)CLC24.00 Spacing L12.00(304.8)(609.6)Table 24.1-8 below illustrates the quantity of plug-in openings perside that are available per standard section.Table 24.1-8. Number of Plug-In OpeningsDuct LengthInchesNumber of Plug-In 812312396.00120.002438.43048.04545TFCLThe plug-in outlet and cover are made from a durable, highstrength, polycarbonate material that is rated as Class B, 130 C,insulation. The plug-in cover is designed to protect the contactsurfaces and prevent the entry of dirt, dust or moisture. The coverhas a positive screw close feature that prohibits the opening ofthe cover without the use of a tool. The cover is also utility“leadlock” sealable.FConfiguration D Top View2 Bars Per Phase12.00(304.8)TFEach section will include one, factory installed, Pow-R-Bridgemounted to the left end of the busway (with the “T” label to thetop, when viewing the bus from the “F” side). Each Pow-R-Bridgewill have a “T” label that must always match the “T” orientationof the busway.Plug-in OutletTCL24.00 Spacing(609.6)12.00(304.8)CLTFFront ViewFigure 24.1-10. Plug-In BuswayCover Can Be Hingedon Either SideHingePinsHigh StrengthPolycarbonateClass B 130ºCACAs a countermeasure to the effects of thermal expansion andmechanical vibration, the plug-in outlet is secured to the buswayhousing with high tensile strength locking lePositiveScrew CloseFeatureFigure 24.1-11. Plug-In Outlet CoverEATON www.eaton.com

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIFittingsEffective February 202024.1-8FittingsRearwardThere is a fitting to meet every application need: flanges,elbows, offsets, tees, cable tap boxes, weatherheads,transformer connections, power take-off sections, reducers,adapter cubicles, expansion joints and end closures.UpwardThese fittings, along with standard and minimum dimensions,are described on the following pages.ForwardWhen making field measurements and layouts, it should beremembered that the dimensions are given from the centerlineof the Pow-R-Bridge.DownwardThe relationship of fittings to straight lengths (forward, rearward,upward and downward) is illustrated in Figure 24.1-12.All straight lengths and fittings are marked with a “T” label andan “F” label. The “T” and “F” locations will also be noted on theconstruction, or the as-built, drawings furnished. When installingthe busway, the “T” and “F” markings of each section mustmatch. Failure to do so will result in an improper installationwith the phase bars out of sequence.Figure 24.1-12. “T” and “F” Orientation for FittingsEnd CloserBuilt-inPowerTake-OffUpward/DownwardCorner JointPlug-inUnit90º lug-inBusProtectedReducerOffsetWallFlangeFloor FlangeUpward/DownwardElbowForward/RearwardCorner JointCenter CableTap � End Cable Tap BoxFigure 24.1-13. Typical Busway ComponentsEATON www.eaton.com

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIFittingsEffective February 202024.1-9ElbowsTable 24.1-9. Forward and Rearward ElbowsAmpere RatingTraditional Indoor and Outdoor ElbowsUL 857See Figure 24.1-14CuElbows are used to make 90 changes in the direction of buswayruns. The four types that are available are forward, rearward,upward and downward. See minimum leg lengths listed foreach type in Table 24.1-9 and Table 24.1-10.All dimensions are to the centerline of the UpwardCLCLCLRearwardXCLFigure 24.1-14. Traditional ElbowsCorner Joint ElbowsSee Figure 24.1-15The Pow-R-Way III Corner Joint Elbow can be installed in areaswhere a traditional 90 turn could never have been accomplishedbefore.Pow-R-Way III Corner Joint Elbows can solve any seriouspathway problem and contribute to successful layouts withminimal space requirements.22540063013.00 (330.2)13.00 (330.2)13.00 (330.2)80010001200600—80010001200140013.00 (330.2)13.00 (330.2)13.50 (342.9)13501600200010001200135015501800225013.50 (342.9)14.00 (355.6)14.50 (368.3)—2500320016002000——3000380015.00 (381.0)16.00 (406.4)18.50 (469.9)4000—50002500320040004500—580019.50 (495.3)20.50 (520.7)22.50 (571.5)Table 24.1-10. Upward and Downward LCLXXYAlIEC 439Minimum Leg Lengths (X)Inches 00 (254.0)10.00 (254.0)10.00 (254.0)13.00 (330.2)13.00 (330.2)13.00 (330.2)80010001200600—80010001200140010.00 (254.0)10.00 (254.0)10.00 (254.0)13.00 (330.2)13.00 (330.2)13.00 (330.2)13501600200010001200155015501800225010.00 (254.0)10.00 (254.0)10.00 (254.0)13.00 (330.2)13.00 (330.2)13.00 (330.2)—2500320016002000——3000380010.00 (254.0)10.00 (254.0)12.00 (304.8)13.00 (330.2)13.00 (330.2)13.00 (330.2)4000—50002500320040004500—580012.00 (304.8)12.00 (304.8)12.00 (304.8)13.00 (330.2)13.00 (330.2)13.00 (330.2)Table 24.1-11. Forward/Rearward Corner JointsAmpere RatingUL 857CuAll dimensions are to the centerline of the CornerJoint Connection.CLCu225400—CuXMinimum Leg Lengths (X)Inches (mm)225400600UL 857CLXAlAmpere RatingCLXIEC 439AlIEC 439DimensionsInches (mm)Cu(X)(Y)225400600225400—2254006300.94 (23.9)0.94 (23.9)0.94 (23.9)5.38 (136.7)5.38 (136.7)5.38 (136.7)80010001200600—8001000120014000.94 (23.9)1.25 (31.8)1.50 (38.1)5.38 (136.7)5.69 (144.5)5.94 (150.9)1350160020001000120013501550180022501.75 (44.5)2.25 (57.2)2.88 (73.2)6.19 (157.2)6.69 (169.9)7.31 (185.7)—2500320016002000——300038003.25 (82.6)4.12 (104.7)6.64 (168.7)7.70 (195.6)8.57 (217.7)11.07 (281.2)4000—50002500320040004500—58007.89 (200.4)8.65 (219.7)10.42 (264.7)12.32 (312.9)13.08 (332.2)14.85 (377.2)CLYCLCLUpwardDownwardFigure 24.1-15. Corner Joint Elbows (For Indoor Applications Only)EATON www.eaton.com

Design Guide DG017002ENLow-Voltage BuswayPow-R-Way IIIFittingsEffective February 202024.1-10Table 24.1-12. Upward/Downward Corner JointsAmpere RatingDimensions in Inches (mm)UL 857CuAlIEC 439Housing GroundCu(X)(Y)(X)Internal Ground(Y)(X)Isolated Ground(Y)Three-Wire225400600225400—2254006304.70 (119.6)4.70 (119.6)4.70 (119.6)4.35 (110.5)4.35 (110.5)4.35 (110.5)4.77 (121.

sandwich bus design available with copper bus bars in ratings from 225–5000 A or with aluminum bus bars from 225–4000 A. Pow-R-Way III is available in outdoor feeder, indoor feeder, indoor plug-in and indoo