1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA RV 1-2014 Application andInstallation Guidelinesfor Armored Cable andMetal-Clad CableNEMA Standards Publication RV 1-2014 Application and Installation Guidelines for Armored Cable and Metal-Clad Cable Published by: National
2、Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, Virginia 22209 Approved August 13, 2014 www.nema.org 2014 National Electrical Manufacturers Association. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Bern
3、e Convention for the Protection of Literary and Artistic Works, and the International and Pan American copyright conventions. 2014 National Electrical Manufacturers Association NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons enga
4、ged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreement among every person participating in the development of this document. The National Electrical Manufacturers Association (NEMA) standards and guideli
5、ne publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers and/or seeks out the views of persons who have an interest in the topic covered by this publication. While NEMA administe
6、rs the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in its standards and guideline
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8、 makes no guaranty or warranty, expressed or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA does not undertake to guarantee the perf
9、ormance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to render professional or other services for or on behalf of any person or entity, nor is NEMA undertaking to perform
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11、rds on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power, nor does it undertake to police or enforce compliance with the contents of this document. NEMA
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13、 or maker of the statement. NEMA RV 1-2014 Page i 2014 National Electrical Manufacturers Association Foreword These application and installation guidelines offer practical information on correct usage and industry-recommended practices for the installation of Type AC and Type MC cables in accordance
14、 with the National Electrical Code. These guidelines were developed by the NEMA Building Wire and Cable section, which has committed to periodically reviewing them for any revisions necessary to address changing conditions, product listing and installation requirements, and technical progress. Comme
15、nts for proposed revisions are welcome and should be submitted to: Senior Vice President, Operations National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, VA 22209 At the time of approval, the members of the NEMA Building Wire and Cable Group that contributed to th
16、e development of NEMA RV 1-2014 were as follows: AFC Cable Systems, Inc., part of Atkore International New Bedford, MA Cerro Wire LLC Hartselle, AL Colonial Wire they provide guidance on only where and how the cable may be used. The following provides additional guidance on the uses of Type AC cable
17、: General A key provision of the permitted uses of Type AC is that Type AC cable is required to comply with all applicable NEC sections. While section 320.10 permits Type AC to be used as branch circuits and feeders, other NEC articles that apply to the particular installation must be reviewed to de
18、termine if additional requirements or restrictions apply. For example, section 517.13(A) permits Type AC cable for use in patient care areas of health care facilities. In accordance with 517.13(B), however, the cable must contain an insulated equipment grounding conductor. Where not subject to physi
19、cal damage Type AC cable must be protected from physical damage. This includes installing the cable at heights and locations where the cable will not be exposed to damage. It also includes providing mechanical protection for the cable from nails and screws, in accordance with section 300.4(D), by ma
20、intaining a 1-1/4 inch (32 mm) distance from the edge of a framing member or by providing a metal plate where the distance cannot be maintained from the edge of a framing member or a furring strip. In exposed and concealed installations Type AC cable is permitted for installation in both exposed and
21、 concealed work; however, the cable must be protected from physical damage. Exposed work includes installations above suspended ceilings where installed behind panels designed to allow access. Section 300.11 should be consulted for requirements for securing and supporting the cable where installed a
22、bove suspended ceilings. In cable tray All UL-listed Type AC cable is acceptable for use in cable tray. There is no marking on the cable that indicates that the cable is identified for such use because the metallic armor enables the cable to meet the flame requirements for cables installed in cable
23、tray. If documentation is required to show that Type AC is identified for use in cable trays, ULs General Information for Electrical Equipment Directory (White Book) contains the necessary information. NEC article 392 should be consulted for cable tray installation requirements. NEMA RV 1-2014 Page
24、4 2014 National Electrical Manufacturers Association In dry locations Type AC cable is rated for only dry locations. The insulation used is not suitable for wet locations. The cable is permitted a limited exposure during building construction as defined in article 100 under dry locations: Dry Locati
25、onA location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction. In addition to permitted uses covered in section 320.10, Type AC is permitted for installation as follows: 1) In
26、other spaces used for environmental air in accordance with section 300.22(C); 2) Under raised floors of computer rooms in accordance with section 645.5(E); 3) In patient care areas of health care facilities, hospitals, and nursing homes in accordance with section 517.13(A) where an insulated equipme
27、nt grounding conductor is used; 4) In essential electrical systems for hospitals in accordance with 517.30(C)(3)(3) under the installation conditions described in 517.30(C)(3)(3) a-d. 5) Isolated or dedicated ground circuits where an insulated equipment grounding conductor is used; 6) Lighting whips
28、; and, 7) Motor leads. Based on the limitations of its construction, its limited size range, number of conductors, and absence of an optional outer non-metallic jacket, Type AC cable is typically used as part of branch circuit wiring in multi-family residential/commercial and institutional applicati
29、ons. Industrial installations typically use Type MC cable, which does not have these limitations. 1.4.1.2 USES NOT PERMITTED As with permitted uses, those uses not permitted by the NEC are not all-inclusive. The Code language is intended to provide guidance on where and how the cable may be used. NE
30、C 320.12 specifies the uses of Type AC that are not permitted, which are as follows: 1) Where subject to physical damage 2) In damp or wet locations 3) In air voids of masonry block or tile walls where such walls are exposed or subject to excessive moisture or dampness 4) Where exposed to corrosive
31、conditions 5) Embedded in plaster finish on brick or other masonry in damp or wet locations Review of the uses not permitted shows a central theme that Type AC cable is not permitted where corrosive environments may be present or in wet or damp locations. For installations where a corrosive environm
32、ent exists, a cable with a protective outer covering such as Type MC with an outer nonmetallic jacket should be used. Similarly, in a wet or damp location, Type MC with wet-rated conductors should be used. 1.4.1.3 RELATED NEC ARTICLES The following NEC articles also contain provisions for the use of
33、 Type AC: Chapter 2: Wiring and Protection Article 250 Grounding 250.118(8) Use of the Armor of Type AC as Equipment Grounding Conductor NEMA RV 1-2014 Page 5 2014 National Electrical Manufacturers Association Chapter 3: Wiring Methods and Materials Article 300 Wiring Methods 300.15 Boxes, Conduit B
34、odies, or FittingsWhere Required 300.16 Raceway or Cable to Open or Concealed Wiring 300.22(C)(1) Wiring Methods (in Plenums) Article 310 Conductors for General Wiring 310.15 Ampacities for Conductors Rated 0-2000 Volts 310.120 Marking Article 320 Armored Cable: Type AC Article 392 Cable Trays 392.1
35、0(A) Wiring Methods Chapter 4: Equipment for General Use Article 410 Luminaires, Lampholders, and Lamps 410.24 Connection of Electric-Discharge and LED Luminaires 410.117(C) Tap Conductors Article 430 Motors, Motor Circuits, and Controllers 430.245 Method of Grounding Chapter 5: Special Occupancies
36、Article 517 Health Care Facilities 517.13(A) Wiring Methods (Patient Care Area Grounding) 517.30(C)(3)(3) Mechanical Protection of the Essential Electrical System Article 518 Assembly Occupancies 518.4 Wiring Methods Article 520 Theaters, Audience Areas of Motion Picture and Television Studios, Perf
37、ormance Areas, and Similar Locations 520.5 Wiring Methods Article 530 Motion Picture and Television Studios and Similar Locations 530.11 Permanent Wiring Article 550 Mobile Homes, Manufactured Homes, and Mobile Home Parks 550.16(A)(2) Connections of Ranges and Clothes Dryers Article 551 Recreational
38、 Vehicles and Recreational Vehicle Parks 551.47(G) Wiring MethodsProtected 551.55(C) Interior Equipment Grounding Article 552 Park Trailers 552.48 Wiring Methods 552.56(C)(1) Interior Equipment Grounding Chapter 6: Special Equipment Article 610 Cranes and Hoists 610.11 Wiring Method Article 620 Elev
39、ators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts 620.21 Wiring Methods 620.81 Metal Raceways Attached to Cars Article 645 Information Technology Equipment 645.5 Supply Circuits and Interconnecting Cables Article 668 Electrolytic Cells 668.30(C) Fixed and Portable
40、 Electrical EquipmentWiring Methods Article 680 Swimming Pools, Fountains, and Similar Installations 680.21(A)(4) MotorsWiring Methods NEMA RV 1-2014 Page 6 2014 National Electrical Manufacturers Association 680.23(F)(1) Underwater LuminariesBranch-Circuit Wiring Article 690 Solar Photovoltaic (PV)
41、Systems 690.31(A) Wiring Systems Reprinted with permission from NFPA 70-2014, the National Electrical Code, 2013 National Fire Protection Association, Quincy, MA 02269. This reprinted material is not the referenced subject, which is represented only by the standard in its entirety. 1.4.2 UNDERWRITER
42、S LABORATORIES (UL) STANDARDS AND DIRECTORIES UL publishes a number of standards and directories that provide detailed information on the construction, performance, application, ratings, and installation aspects of Type AC cable. 1.4.2.1 UL STANDARDS The UL standard for the construction and performa
43、nce of Type AC cable is UL 4. According to NEC section 320.104, the insulated conductors for AC cable must be of the types listed in Table 310.104(A) or one identified for use in this cable. Practically all Type AC cable contains Type THHN, a thermoplastic insulated conductor covered in UL 83. Insul
44、ation types, however, could be a thermosetting type, such as Type XHH or RHH conductors covered in UL 44. 1.4.2.2 UL DIRECTORIES UL publishes several directories that contain useful information on the products that it lists, recognizes, and certifies. The directories are frequently used by installer
45、s and inspection authorities to gain a better understanding of how to specify and install products in accordance with their listing. All of this information is readily available at the UL website. These directories are helpful tools for understanding the details of how products, in this case Type AC
46、 cable, are constructed and marked, and provide information on special or optional ratings and terminations. One of the directories covers the UL-approved methods for maintaining the fire resistive rating on walls, floors, and ceilings for fire resistancerated construction when cables must penetrate
47、 them and be fire-stopped. The primary directory used for electrical products is the White Book, some of which is reprinted below. 1. UL Guide Information for Electrical EquipmentWhite Book The following information on Type AC cable is reprinted from the UL Guide Information for Electrical Equipment
48、, with permission from Underwriters Laboratories Inc., 2013 Underwriters Laboratories Inc.: Armored Cable (AWEZ) GENERAL This category covers armored cable in sizes 14-1 AWG copper and 12-1 AWG aluminum or copper-clad aluminum and rated 600 V or less. Aluminum-armored cable is suitable for use in al
49、ternating current circuits only. Armored cable is for use in accordance with Article 320 of ANSI/NFPA 70, NEC. ACTHIndicates armored cable rated 75C employing conductors having thermoplastic insulation. ACTHHIndicates armored cable rated 90C employing conductors having thermoplastic insulation. ACHHIndicates armored cable rated 90C employing conductors having thermosetting insulation. Armored cable connectors (box connectors) other than the direct bearing setscrew type are suitable for use on cable employing aluminum armor. NEMA RV 1-2014 Page 7 2014 Nation
