1、An Americ An nAtion Al StAndArdNECA/AA 104-2012 Standard for InstallingAluminum Building Wire and CablePublished byNational Electrical Contractors AssociationJointly developed withThe Aluminum AssociationA nRecommended Practice forInstalling Aluminum BuildingWire and CableNECA/AA 104-2012An American
2、National StandardnullPublished byNational Electrical Contractors AssociationJointly developed withThe Aluminum AssociationNOTICE OF COPYRIGHTThis document is copyrighted by NECAReproduction of these documents either in hard copy or soft (including posting on the web) is prohibited without copyright
3、permission. For copyright permission to reproduce portions of this document, please contact NECA Standards and AC, MC, TC and SE.1.2 Products and Applications ExcludedThis publication does not cover aluminum alloy conductors used in electric utility applications.1.3 Regulatory and Other Requirements
4、a) All information in this publication is intended to comply with the National Electrical Code (NFPA 70). Installers should always follow the NEC, applicable state and local codes, and manufacturers instructions when installing aluminum building wire and cable.b) Only qualified persons as defined in
5、 the NEC who are familiar with the installation of aluminum building wire and cable should perform the work described in this publication. c) Other National Electrical Installation Standards provide guidance for installing additional types of electrical products and systems. A complete list of NEIS
6、is provided in Annex A.n 21. Scope2.1 GeneralInstallation procedures for aluminum alloy building wire products are typical of the procedures required for electrical wire and cable products.2.2 Stripping Insulationa) One way to remove insulation is to pencil or whittle it (Figure 1). Another method i
7、s to skin the insulation back from the cut end of the conductor and then cut outward (Figure 2).b) A quicker and easier way is to use one of the several types of insulation strippers that are available to remove insulation. Figure 3 shows a type useful for popular sizes of conductors (6 AWG through
8、750 kcmil).c) Do not “ring cut” the insulation from a conductor or cable, using knife or pliers. Doing so can nick or damage the conductors inside.2.3 Splicing Aluminum ConductorsAluminum conductors should be spliced using connectors as described in 3.1.2.3.1 Underground connectionsTypically, compre
9、ssion-type connectors are used for underground applications, although screw-type connectors are available for some underground applications. A splice box may or may not be required for these connections. Follow these steps to splice aluminum conductors using compression-type connectors:a) Strip the
10、insulation from the end of each conductor. Strip back far enough so the conductor will go fully into the connector, but also make sure the insulation fits closely to the connector. Wire-brush the stripped conductor.b) Insert the stripped end of the conductor into the connector as far as it will go.
11、Typically, manufacturers supply these connectors filled with joint compound to seal the splice against moisture and other contaminants. c) Apply the crimping tool designed for that type of connector and crimp fully in accordance with the manufacturers instructions (Figure 4). Be sure to select the c
12、orrect crimping tool die for the size of the connector and the conductor being spliced.2. Basic Installation TechniquesFigure 1Figure 2 Figure 33 nStandard for Installing Aluminum Building Wire and Cable NECA/AA 104d) Wipe off any excess joint compound and insulate the connection using tape, heat or
13、 cold-shrinkable tubing or other approved insulating material.2.3.2 Above-ground connectionsBoth compression-type and screw-type connectors are used for above-ground applications. Compression-type connections are typically made inside electrical equipment or a splice box. Size the box to accommodate
14、 the number of conductors and connectors. Follow the instructions in 3.1.3 for installing compression-type connectors. Screw-type connections are typically made inside electrical equipment or junction boxes with built-in terminal strips; these are supplied as an integral part of equipment such as mo
15、tors and transformers. Install mechanical screw-type terminal lug connectors as described in 3.1.2. Install compression-type terminal lug connectors as described in 3.1.3. 2.4 Pulling Aluminum Conductors in Conduits and RacewaysFollow these steps to install aluminum conductors in conduits and racewa
16、ys:a) Be sure that the raceway is sized in accordance with the requirements of the NEC.b) Run a “fish” line through the conduit.NOTE: Attaching the line to a piston-type device, which is propelled through the conduit by compressed air, can do this. Another method is to push a round flexible speedome
17、ter type steel wire through the conduit. Polyethylene fish tapes can be used for shorter runs up to about 30 meters (100 ft).c) Attach a clean-out brush to the fish line and behind it attach the pull line. Then pull both through the conduit by means of the fish line.d) Where appropriate, use a baske
18、t grip over the insulation to attach the pull line to the conductor or conductors (Figure 5).e) Where conductors are pulled with a rope, stagger the conductor ends and anchor in position with tape, to provide maximum flexibility around bends (Figure 6). If using a plexed cable assembly, cut the cond
19、uctors to different lengths in order to stagger the pulling heads or attach a basket grip over the entire assembly.f) Where possible, feed conductors into the conduit end closest to the sharpest bend to reduce pulling tension.Figure 4 Figure 5n 4NECA/AA 104 Standard for Installing Aluminum Building
20、Wire and Cableg) To avoid unduly stressing the conductors, ensure that pulling equipment is of adequate power to provide a steady tension on the cables and avoid jerks.h) Use pulling compound compatible with the conductor insulation as the conductors are fed into the raceways, to reduce friction and
21、 required pulling tension. Note: Some conductors may not require pulling compound, check with the cable manufacturer.i) Wherever possible, when feeding multiple conductors or cables into a conduit or raceway, stagger the reels one behind the other so as to maintain equal pulling tensions, and preven
22、t conductor or cable cross-over and jamming in the conduit.j) Where possible, pull conductors in a downward direction, to allow gravity to assist in pulling with reduced tension.2.5 Installing Aluminum Cables in Trays and RacksWhere conductors and cables are to be installed in trays or cable racks,
23、follow the applicable steps in Section 2.3, plus the following:a) Follow the requirements of NEC Article 392 to determine the allowable number of wires or cables permitted in trays and their respective ampacities. To be suitable for use in cable trays, the conductors and cables are required to meet
24、the requirements for and include the marking “For CT Use.” Except as permitted in the NEC, single conductors installed in cable trays are required to be 1/0 AWG and larger. Equipment grounding conductors may be 4 AWG and larger.NOTE: Although the conductors used in cable trays may have a higher ampa
25、city than the same conduc-tors installed in raceways, it is generally not possible to utilize the higher ampacities for two reasons. First, the conductors installed in the trays generally end up in a raceway, which limits the rated ampacity of the circuit. Second, equipment rated for up to 600 Volts
26、 is evalu-ated using ampacities from the 75C column of NEC Table 310.15(B)(16) in accordance with Section 110.14 and applicable UL standards.Figure 6Table 2 Nonshielded Power Cables Without Metallic Shielding or ArmorThe minimum bending radius for a single conductor, a multiplexed assembly, or multi
27、conductor nonshielded cable without any metallic sheath or armor.Overall Diameter of CableThickness of Conductor Insulationinches 1.000 a terminal block should be used for connecting multiple conductors.Figure 7n 61. Scope3.1 Connector TypesPressure-type connectors for use with aluminum conductors c
28、ome in two basic types: Mechanical screw-type Compression-type Both types are designed to apply sufficient pressure to provide low resistance metal to metal contact. The connectors are usually plated to avoid oxidation and to resist corrosion. Most compression connectors are supplied by the manufact
29、urers already filled with joint compound to seal the connection from moisture and other contaminants.Pressure-type connectors are available in many configurations; Figure 8 shows some typical connectors.3. Connection Techniques for Aluminum ConductorsFigure 8Figure 9Figure 107 nStandard for Installi
30、ng Aluminum Building Wire and Cable NECA/AA 1043.1.1 Listing and markingPressure-type connectors listed for use with both aluminum and copper conductors are marked AL7CU or AL9CU (or CU7AL or CU9AL).NOTE: Pressure-type connectors rated for 6 AWG or smaller conductors may have the markings on the con
31、nector, the unit container, or an information sheet packed in the unit container. Also, The AL7CU or AL9CU marking is not required on equipment connectors. However, the equipment bears a marking, such as AL-CU, indicating that they are suitable for both aluminum and copper conductors.Connectors list
32、ed for use with aluminum conductors are listed in the UL Electrical Construction Equipment Directory. The category name for these connectors is “Wire Connectors and Soldering Lugs (ZMVV).”3.1.2 Installation procedure mechanical screw-type connectorsFollow these general procedures to install connecto
33、rs. All manufacturers instructions should also be followed:a) Use listed AL7CU or AL9CU connectors sized to accept aluminum conductors of the ampacity specified.b) Using a suitable stripping tool to avoid damage to the conductor, remove insulation from the required length of the conductor.c) Wire br
34、ush the conductor and apply a Listed joint compound.d) Tighten the connection (Figure 9) per the connector manufacturers recommendation. In absence of specific recommendations, use the torque values shown in Tables 3.1, 3.2, and 3.3. Expanded tables can be found in the 2011 NEC, Annex I. Use the “B”
35、 tables in those charts for field terminations.e) Wipe off any excess joint compound.3.1.3 Installation procedures compression-type connectorsFollow these general procedures to install connectors. All manufacturers instructions should also be followed:a) Use listed AL7CU or AL9CU connectors sized to
36、 accept aluminum conductors of the ampacity specified.b) The lugs should be marked with wire size, die index, number and location of crimps and should be suitably color coded. Lug barrel should be factory pre-filled with a Listed joint compound.Table 3.1 Tightening Torque for Slotted Head Screws Sma
37、ller than No. 10 Intended for Use With 8 AWG or Smaller ConductorsTightening Torque, Pound-Inches (N-m)Slot Length of Slot Width of Screw Slot Width of ScrewScrew Smaller Than 0.047 Inch (1.2 mm)0.047 Inch (1.2 mm) and Larger,Inch (mm) Inch (mm) Inch (mm)Less than 5/32 (4) 7 (0.79) 9 (1.0)5/32 (4) 7
38、 (0.79) 12 (1.4)3/16 (4.8) 7 (0.79) 12 (1.4)7/32 (5.6) 7 (0.79) 12 (1.4)1/4 (6.4) 9 (1.0) 12 (1.4)9/32 (7.1) 15 (1.7)Above 9/32 (7.1) 20 (2.3)n 8NECA/AA 104 Standard for Installing Aluminum Building Wire and Cablec) Using a suitable stripping tool, to avoid damage to the conductor, remove insulation
39、 from the required length of the conductor.d) Wire brush the conductor.e) Crimp the connection (Figure 10) per connector manufacturers recommendations.f) Wipe off any excess joint compound.g) If required, tape the joint as described in 2.3 or apply the insulating enclosure, if provided, with the con
40、nector.3.2 Joint CompoundConductor Termination Compounds (commonly known as joint compounds or oxide inhibitors) are used on splice and termination connections of aluminum, copper-clad aluminum, and copper conductors where needed to retard oxidation at conductor/connector interface. Joint compounds
41、are produced in many varieties, all with special properties appropriate for their intended use. Compound should be compatible with conductor insulation and components used for splicing and terminating. These compounds do not have a deleterious effect on the conductor metal, insulation or equipment w
42、hen used in accordance with the manufacturers installation instructions.A Listed joint compound is applied to the bare conductor after it has been wire brushed. A coating of joint compound remains on the surface of the conductors, preventing moisture or other contaminants from contacting the connect
43、ion area.NOTE: Some joint compounds contain coarse grit or metallic particles, which make them unsuitable for flat-bar connections.3.3 Terminal LugsListed terminal lugs marked AL7CU or AL9CU are used to connect aluminum conductors to transformers, switches, bus bars, motors and other equipment. Alum
44、inum terminals are usually plated to resist corrosion, and these plated connectors should not be wire brushed or abraded.Like connectors, terminal lugs are of two basic types: mechanical screw type and compression type applied by tool and die. Figure 11 shows typical terminal lugs. They are applied
45、to the conductor ends in the same manner described in 3.1.Care should be taken that conductor temperature and ampacity ratings are compatible with the terminals and equipment to which they are to be connected. See the markings on the equipment, the instructions furnished with the equipment, or the i
46、nstallation instructions (drawings) for the project for these details.3.3.1 Installation procedureWhen all components are aluminum (bus, studs, and lugs), aluminum bolts should be used to make the connections. Follow these steps:a) Use the components furnished or specified by the equipment manufactu
47、rer. These may include: Aluminum bolts should be anodized alloy 2024-T4 and conform to ANSI B18.2.1 specifications and to ASTM B211 or B221 chemical and mechanical property limits.Table 3.2 Tightening Torque for Socket Head ScrewsSocket Size Across Tightening Torque, Flats Pound-Inches (N-m)Inch (mm
48、) Inch (mm)1/8 (3.2) 45 (5.1)5/32 (4.0) 100 (11.3)3/16 (4.8) 120 (13.6)7/32 (5.6) 150 (16.9)1/4 (6.4) 200 (22.6)5/16 (7.9) 275 (31.1)3/8 (9.5) 375 (42.4)1/2 (12.7) 500 (56.5)9/16 (14.3) 600 (67.8)9 nStandard for Installing Aluminum Building Wire and Cable NECA/AA 104 Nuts should be aluminum alloy 60
49、61-T6 or 6262-T9 and conform to ANSI B18.2.2. Washers should be flat aluminum alloy 2024-T4, Type A plain, standard wide series conforming to ANSI B27.2. SAE or narrow series washers should not be used.b) Hardware should be assembled as shown in Figure 12. Lubricate all hardware with silicon spray or other suitable lubricant before tightening. If bolts are not lubricated, torque may vary widely and result in high contact resistance at joints. Tighten bolts to the manufacturers recommended torque. In the absence of specific recommen
