1、Standard for InstallingAluminum RigidMetal ConduitNECA 102-2004AMERICAN NATIONAL STANDARDPublished byNational Electrical Contractors AssociationTStandard for InstallingAluminum RigidMetal ConduitNECA 102-2003An AmericanNational StandardPublished byNational Electrical Contractors Associationiii a73Fo
2、reword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .v1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.1 Products and Applications
3、Included . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.2 Products and Applications Excluded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.3 Regulatory and Other Requirements . .
4、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 3. General Product Information . . . . . . . . . . . . . . . .
5、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33.2 Manufactured Elbows . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33.3 Nipples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43.4 Couplings . . . . . . . . . . . . . . . . . . . . . . . .
7、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43.5 PVC-Coated Aluminum Rigid Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44. General Installation Practices . . . . . . . . . . . . .
8、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.1 Cutting and Threading Aluminum RMC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.2 Bending Aluminum RMC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9、. . . . . . . . . . . . . . . . . . . . . . . . . . . 64.3 Joining Aluminum RMC with Integral Couplings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.4 Installing Fittings on Aluminum Rigid Metal Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10、 . . . . . . . . . . 84.5 Supporting Aluminum Rigid Metal Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94.6 Firestopping and Fire Blocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11、 . . 104.7 Corrosion Protection for Special Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105. Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 5.1 Bonding Servic
12、e Raceways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 5.2 Expansion Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126. Specifi
13、c Installation Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 6.1 All Raceways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136.2 Conduits for Communic
14、ations Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 6.3 Verifying the Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137. PVC-Coated Aluminum Rigid
15、Metal Conduit (RMC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147.1 Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147.2 Clamping (Vising) PVC-Coated Conduit . . . . . .
16、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147.3 Cutting and Threading PVC-Coated Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147.4 Bending PVC-Coated Aluminum Rigid Metal Conduit . . . . . . . . . . . . . .
17、 . . . . . . . . . . . . . . . . . . . . . . . 157.5 Installing PVC-Coated Aluminum Rigid Metal Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157.6 Patching Damaged Areas of PVC-Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . 167.7 Equipment Grounding and Bonding with PVC-Coated Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Annex A: Reference Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21Table of Contentsa73 ivv a73National
19、Electrical Installation Standardsare intend-ed to improve communication among specifiers, pur-chasers, and suppliers of electrical construction ser-vices. They define a minimum baseline of qualityand workmanship for installing electrical productsand systems. NEISare intended to be referenced incontr
20、act documents for electrical construction pro-jects. The following language is recommended:Aluminum rigid metal conduit shall be installedin accordance with NECA 102-2003, Standardfor Installing Aluminum Rigid Metal Conduit(ANSI).Use of NEIS is voluntary, and the National ElectricalContractors Assoc
21、iation assumes no obligation or lia-bility to users of this publication. Existence of astandard shall not preclude any member or non-member of NECA from specifying or using alternateconstruction methods permitted by applicable regu-lations.This publication is intended to comply with the edi-tion of
22、the National Electrical Code (NEC) in effectat the time of publication. Because they are qualitystandards, NEIS may in some instances go beyondthe minimum requirements of the NEC. It is theresponsibility of users of this publication to complywith state and local electrical codes when installingelect
23、rical products and systems.Suggestions for revisions and improvements to thisstandard are welcome. They should be addressed to:NECA Standards consult manufactur-ers listings and markings. (NOTE: For installation inconcrete or directly buried in soil, supplementary corro-sion protection is required.
24、See 4.7.)3.1.1 Trade SizesAluminum RMC is a listed threaded metal racewayof circular cross-section, that comes with a factory-installed threaded coupling on one end. The nomi-nal finished length with coupling is 10 feet.Aluminum RMC is available in trade sizes 1/2through 6. Threaded ends are covered
25、 by color-coded thread protectors, which also aid in size recog-nition: BLUE thread protectors: “full inch” trade sizes 1,2, 3, 4, 5, 6. BLACK thread protectors: “half inch” trade sizes1/2, 1-1/2, 2-1/2, 3-1/2. RED thread protectors: “quarter inch” trade sizes3/4, 1-1/4.(See Table 1 for Metric Trade
26、 Size Designators.) 3.1.2 MaterialsAluminum RMC has a protective coating of alu-minum oxide. This oxide layer protects the conduitand its contents from a variety of corrosive factors,such as the outdoor environment and corrosivechemicals. Other types of supplemental coatingsmay be applied where addi
27、tional corrosion protec-tion is required. (NOTE: Contact manufacturerswith product-specific questions).Aluminum RMC is manufactured with a PVC coatingfor installation in highly corrosive atmospheres. Seesection 7 for special installation practices and toolsrequired when working with PVC-coated condu
28、it.3.2 Manufactured Elbowsa) Elbows are bent sections of conduit, threaded oneach end. Factory-made elbows in both standard andspecial radius are readily available for all sizes of alu-minum rigid RMC. Elbows with integral couplingsare available in trade sizes 1/2 through 4.b) Physical dimensions of
29、 factory-made elbows foraluminum rigid metal conduit vary from one manu-3. General Product Information3 a73Table 1 Metric Trade Size Designators for Rigid Aluminum ConduitEnglish Metric1/2 163/4 211271 1/4 351 1/2 41252 1/2 633783 1/2 914 1035 1296 155facturer to the next. To avoid problems, always
30、mea-sure carefully when roughing-in conduit runs.When ordering aluminum RMC factory elbows, it isnecessary to specify the manufacturer, trade size, andangle of bend.c) Special large-radius elbows (often referred to as“sweeps”) can be custom-ordered. They are used tosolve particular installation prob
31、lems such as easierwire pulling, installing conduit in limited or geomet-rically difficult spaces, providing a specific stub-uplength, or enhancing protection of communicationsor fiber optic cables during pulls.3.3 NipplesFactory-made aluminum rigid metal conduit nipplesare threaded on both ends. Li
32、sted nipples are avail-able in all trade sizes, in lengths up to 24 inches.3.4 CouplingsFactory-made couplings for aluminum RMC areavailable in all trade sizes. Integral couplings areavailable on trade sizes 1/2 through 4. These integralcouplings permit joints to be made up by turning theoutside cou
33、pling rather than the conduit.3.5 PVC-Coated Aluminum Rigid ConduitThis product is described in Section 7, along withspecial installation practices.NECA 102 Standard for Installing Aluminum Rigid Metal Conduita73 44.1 Cutting and Threading Aluminum RMC (NOTE: Although coupling threads are straight-t
34、apped, conduit threads are tapered.)4.1.1 Cutting Aluminum RMCa) Cut the conduit to length with a saw or roll cutter.Be careful to make a straight cut or the die will cutcrooked threads.b) To cut conduit using a wheel-and-roll cutter,revolve the cutter completely around the pipe (Figure1). Tighten t
35、he handle about one-quarter turn aftereach rotation and repeat this procedure until theconduit is cut through.c) After cutting, ream the interior and remove sharpedges from the exterior (Figure 2). (NOTE: Reamingthe conduit after threading will stretch or oval the endof the conduit.)4.1.2 Setting Up
36、 the DiesPerform field threading in accordance with the fol-lowing procedures, unless manufacturers instructionsdiffer. Follow the manufacturers operating and safetyinstructions when operating threading equipment.a) Use a standard National Pipe Thread (NPT) diewith a taper of 3/4 inch per foot, as d
37、efined in ANSI/ASME B120.1.b) Dies must be sharp to produce full, clean threads;worn dies produce ragged, torn threads, or threadswhich are not cut deep enough.c) To adjust dies, loosen the screws or locking collarthat hold the cutting dies in the head. When the4. General Installation Practices5 a73
38、Figure 1 Cutting aluminum RMC with a burr cutter Figure 2 Reaming freshly-cut aluminum RMCscrews or collar are loosened, the dies should movefreely away from the head.d) Screw the die head onto the threaded portion of afactory-threaded nipple or factory-threaded conduituntil the die fits the factory
39、 thread (Figure 3). If thedie head has an adjusting lever, set the head to cut aslightly oversized thread.(NOTE: This is ordinarily one thread short of beingflush with the face of a thread gauge, when the gauge ishand tight. This is within the tolerance limits whichallow the thread to be one thread
40、short or long of beingflush with the gauge face.)e) Tighten the screws or locking collar so that thedies are tightly held in the head.f) Remove the set-up piece of threaded conduit. Thedie is ready for use.4.1.3 Threading Aluminum RMCa) To start a universal die head, press it against theconduit end
41、with one hand and turn the stock withthe other. With a drop head die, the stock remainsstationary and the head rotates. After the dies haveengaged for a thread or two, they will feed along theconduit without pressure.b) Stop the cutting as soon as the die has taken holdand apply thread cutting oil f
42、reely to the dies and thearea to be threaded. Keeping dies flooded with agood grade of cutting oil lubricates the conduit andproduces smoother threads by reducing friction andheat. Using insufficient cutting oil can cause raggedthreads.c) Cut one thread short of the end of the chaser.d) Back the die
43、 head off and clean the chips fromthe thread, using a brass brush (Figure 4). Do notuse brushes with steel bristles on aluminum conduitthreads.4.2 Bending Aluminum RMCWhile many sizes of factory elbows are manufac-tured, the variety of electrical installations makesfield-bending necessary. Make bend
44、s after conduit isthreaded.4.2.1 General Informationa) Follow the bender manufacturers operating andsafety instructions when operating equipment. Thebender, its components, and accessories must bematched to the conduit type and size being bentbecause of the forces being applied. When using aNECA 102
45、 Standard for Installing Aluminum Rigid Metal Conduita73 6Figure 3 Setting up dies to thread aluminum RMCFigure 4 Brushing chips from the threads of aluminumRMCpower bender, make sure that pins are in the properpin holes for the size of conduit being bent.b) Accurately measure and mark the conduit w
46、ith athin line that goes completely around the conduit.This assures the mark is visible if the conduit needsto be rotated.c) Make radius measurements to the centerline ofthe bend.d) Slight overbending may be necessary to compen-sate for springback.e) Trade sizes 1/2, 3/4, and 1 can be bent with ahan
47、d-type bender. Trade sizes 1-1/4 and 1-1/2require a power bender or a mechanical ratchet-typebender. Bend trade sizes 2 and larger on a powerbender. (NOTE: Benders recommended for a largersize range may also be capable of bending some sizesbelow their primary range.)f) Do not place ends of aluminum
48、RMC in the hookor bending shoe of the bender, because thread dam-age and end-flattening will occur.4.2.2 Using Hand Bendersa) Some hand benders do not have degree markings.Degrees of bend must be measured on the inner surfaceof the conduit that fits into the groove of the bender.b) When using a hand
49、 bender, choose a solid, flatsurface. Pin the conduit firmly to the surface withsteady foot pressure sufficient to keep the conduit andbender marks aligned, and the conduit nestled in thegroove, throughout the full arc of the bend (Figure 5).4.2.3 Using EMT BendersAluminum RMC can often be bent using bendersdesigned for electrical metallic tubing (EMT). If themanufacturers instructions do not prohibit using theequipment with aluminum RMC, use an EMT shoeone trade size larger than the conduit to be bent (tobend trade size 3/4 PVC-coated aluminum RMC, usea trade size 1 EMT be
