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1、 ANSI/NEMA FB 1 ANSI/NEMA FB 1 FITTINGS, CAST METAL BOXES, AND CONDUIT BODIES FOR CONDUIT, ELECTRICAL METALLIC TUBING, AND CABLE Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08
2、:32:46 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:32:46 MDTNo reproduction or networking permitte
3、d without license from IHS -,-,- Approved as an American National Standard ANSI Approval Date: June 4, 2003 NEMA Standards Publication FB 1-2003 Fittings, Cast Metal Boxes, and Conduit Bodies for Conduit, Electrical Metallic Tubing, and Cable Published by National Electrical Manufacturers Associatio
4、n 1300 North 17th Street, Suite 1847 Rosslyn, VA 22209 www.nema.org Copyright 2003 by the National Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal copyright Convention, the Berne Convention for the Protection of Literary and A
5、rtistic Works, and the International and Pan American Copyright Conventions. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:32:46 MDTNo reproduction or networking permitted wi
6、thout license from IHS -,-,- NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreem
7、ent among every person participating in the development of this document. The National Electrical Manufacturers Association (NEMA) standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This proc
8、ess brings together volunteers and/or seeks out the views of persons who have an interest in the topic covered by this publication. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independent
9、ly test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in its standards and guideline publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, cons
10、equential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA disclaims and makes no guaranty or warranty, expressed or implied, as to the accuracy or completeness of any information published herein, and disclaims and make
11、s no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA does not undertake to guarantee the performance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document a
12、vailable, 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 any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropri
13、ate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or informa
14、tion 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 does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compli
15、ance with any health or safety related information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical St
16、andards 1/9972545001 Not for Resale, 04/19/2007 08:32:46 MDTNo reproduction or networking permitted without license from IHS -,-,- FB 1-2003 Page i Copyright 2003 by the National Electrical Manufacturers Association. CONTENTS Page Forewordv Section 1 GENERAL 1.1 Scope1 1.2 Normative References1 1.3
17、Units of Measurement 2 1.4 Definitions .3 Section 2 GENERAL REQUIREMENTS 2.1 General .5 2.1.1 Applicability.5 2.1.2 Assembly and Mechanical Protection .5 2.1.3 Materials.5 2.1.4 Thread Form and Dimensions.6 2.1.5 Resistance to Corrosion.6 2.1.6 Electrical Protection .6 2.1.7 Environmental Classifica
18、tions6 2.1.8 Marking.7 2.2 FittingsGeneral .7 2.2.1 Functionality .7 2.2.2 Wall Thickness.7 2.2.3 Connectors.7 2.2.4 Couplings8 2.2.5 Thread Form and Dimensions.8 2.3 Cast Metal Boxes, Junction Boxes, Pull Boxes, and Conduit BodiesGeneral.8 2.3.1 Openings8 2.3.2 Conduit Bodies Used as Fittings .8 2.
19、3.3 Conduit Bodies Used as Boxes.8 2.3.4 Conduit Entries.8 2.3.5 Wall Thickness.9 2.3.6 Thread Form and Dimensions.9 2.3.7 Resistance to Corrosion.9 Section 3 SPECIFIC REQUIREMENTS 3.1 General .13 3.1.1 Applicability.13 3.1.2 Functionality .13 3.1.3 Offset and Angle Fittings13 3.2 Fittings-Specific.
20、13 3.2.1 Fittings for Threaded and Unthreaded Non-flexible Metal Circular Raceways13 3.2.2 Fittings for Use with Flexible Metal Conduit13 3.2.3 Fittings for Use with Armored Cable13 3.2.4 Fittings for Use with Metal-Clad Cable15 3.2.5 Fittings for Use with Mineral-Insulated Cable15 3.2.6 Fittings fo
21、r Use with Liquidtight Flexible Metal Conduit15 3.2.7 Fittings for Use with Liquidtight Flexible Nonmetallic Conduit16 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:32:46 MDT
22、No reproduction or networking permitted without license from IHS -,-,- FB 1-2003 Page ii Copyright 2003 by the National Electrical Manufacturers Association. Page 3.2.8 Locknuts Provided with Fittings.16 3.2.9 Conduit Locknuts .16 3.2.10 Bushings.17 3.2.11 Marking.17 3.2.12 Ground Clamps17 3.2.13 Pu
23、lling, Strain Relief, and Support Grips.17 3.2.14 Reducing Washers.17 3.2.15 Service-Entrance Heads, Caps.17 3.2.16 Sill Plates18 3.2.17 Bushings for Use in Metal Studs .18 3.2.18 Closure Plugs and Plates.18 3.3 Outlet Boxes, Conduit Bodies, Junction Boxes, Pull Boxes, and CoversSpecific .19 3.3.1 M
24、arking.19 3.3.2 Cast Metal Outlet Boxes19 3.3.3 Conduit Bodies.20 3.3.4 Dimensions.20 Section 4 DESIGN TESTS 4.1 General .29 4.1.1 Design Tests 29 4.1.2 Test Sampling 29 4.1.3 Nonmetallic Materials.29 4.2 Mechanical Protection29 4.2.1 Assembly Test (2.1.2.2).29 4.2.2 Rod Entry Test (2.2.3.6).29 4.2.
25、3 Mechanical Performance Testing Sequence29 4.3 Electrical Protection30 4.3.1 Fault Current Test (Clause 2.1.6.1).30 4.3.2 Electrical Continuity Test (Clause 2.1.6.2)30 4.4 Environmental Classification30 4.4.1 Rain Test (2.1.7.1)30 4.4.2 Concrete Test (2.1.7.2)30 4.4.3 Oil Spray Test (2.1.7.3)30 4.4
26、.4 Type Rated Fittings and Boxes .30 Section 5 MANUFACTURING STANDARDS 5.1 Threads for Fittings, Cast Metal Boxes, and Conduit Bodies.31 5.1.1 Fittings and Conduit Entries with InternalTapered Threads.31 5.1.2 Fittings and Conduit Entries with Internal Straight Threads .31 5.1.3 Fittings and Conduit
27、 Entries with External Straight Threads32 5.1.4 Fittings with External Tapered Threads.32 5.2 Knockout Dimensions.32 5.3 Dimensions of Flat Surfaces Surrounding Knockouts.32 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standar
28、ds 1/9972545001 Not for Resale, 04/19/2007 08:32:46 MDTNo reproduction or networking permitted without license from IHS -,-,- FB 1-2003 Page iii Copyright 2003 by the National Electrical Manufacturers Association. TABLES Table 1-1 TRADE SIZE AND METRIC DESIGNATORS.4 Table 2-1 STANDARD ASSEMBLY TORQU
29、E VALUES FOR CONDUIT AND CABLE FITTINGS .10 Table 2-2 INSIDE DIAMETER OF THROATS AND END STOPS10 Table 2-3 THICKNESS OF ZINC CORROSION PROTECTIVE COATING11 Table 2-4 WALL THICKNESS OF FITTINGS11 Table 2-5 METAL THICKNESS.11 Table 2-6 MINIMUM THREAD PROJECTION OF BOX CONNECTORS.12 Table 2-7 MINIMUM W
30、ALL THICKNESS AT TAPPED HOLES FOR CONDUIT .12 Table 3-1 DIAMETER OF PLUG GO-GAUGE 22 Table 3-2 RADIUS OF BEND OF ANGLE FITTINGS.22 Table 3-3 OUTSIDE DIAMETER OF FLEXIBLE METAL CONDUIT FITTING OF THE SCREW-IN TYPE22 Table 3-4 ARMORED CABLE BUSHING DIMENSIONS23 Table 3-5 DISTANCE FROM REMOVABLE COVER
31、TO OPPOSITE WALL WITH RACEWAY OPENING.23 Table 5-1 NUMBER OF TURNS TO COMPLETELY DISENGAGE THE HAND-TIGHT NPT PLUG GAUGE FROM THE CONDUIT ENTRY.32 Table 5-2 GAGING REQUIREMENTS FOR INTERNAL STRAIGHT PIPE THREADS FOR CONDUIT FITTINGS HAVING SHORT THREADS ON BUSHINGS OR HUBS FOR USE WITH THREADED RIGI
32、D METAL CONDUIT, THREADED INTERMEDIATE METAL CONDUIT, OR OTHER ELECTRICAL FITTINGS HAVING TAPERED OR STRAIGHT EXTERNAL THREADS (CUT THREADSFOR ORDINARY LOCATION APPLICATIONS ONLY) 33 Table 5-3 GAGING REQUIREMENTS FOR EXTERNAL TAPERED THREADS FOR CONDUIT FITTINGS FOR USE WITH THREADED RIGID METAL CON
33、DUIT COUPLINGS, THREADED INTERMEDIATE METAL CONDUIT COUPLINGS, OR OTHER ELECTRICAL FITTINGS HAVING TAPERED OR STRAIGHT EXTERNAL THREADS (CUT THREADSFOR ORDINARY LOCATION APPLICATIONS ONLY)33 Table 5-4 COMPATIBILITY OF KNOCKOUT DIMENSIONS WITH LOCKNUTS, BUSHINGS, AND METAL CONDUIT (IMC OR RIGID) TO A
34、SSURE COORDINATION35 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:32:46 MDTNo reproduction or networking permitted without license from IHS -,-,- FB 1-2003 Page iv Copyright
35、 2003 by the National Electrical Manufacturers Association. FIGURES Figure 3-1 TANGENTIAL TYPE SCREW.24 Figure 3-2 RADIAL TYPE SCREW.24 Figure 3-3 BASIC DIMENSIONS OF INTERNAL STRAIGHT PIPE THREADS FOR LOCKNUTS FOR USE WITH ELECTRICAL CONNECTORS HAVING TYPE NPT SHORT TAPERED EXTERNAL THREADS OR TYPE
36、 NPSM STRAIGHT EXTERNAL THREADS .25 Figure 3-4 BASIC DIMENSIONS AND DIMENSIONS OF INTERNAL STRAIGHT PIPE THREADS FOR CONDUIT LOCKNUTS.26 Figure 3-5 CONFIGURATION OF SINGLE-GANG FS AND FD BOX FACE (also applicable to single-gang box faces on multi-gang boxes).27 Figure 3-6 STRAIGHT PULL TYPE-C28 Figu
37、re 3-7 ANGLE PULL ENTRY OPPOSITE REMOVABLE COVER TYPE-LB28 Figure 5-1 FLAT SURFACES SURROUNDING KNOCKOUTS.34 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:32:46 MDTNo reprodu
38、ction or networking permitted without license from IHS -,-,- FB 1-2003 Page v Copyright 2003 by the National Electrical Manufacturers Association. Foreword This Standards Publication provides practical information concerning construction, test, performance, and manufacture of fittings, cast metal bo
39、xes, and conduit bodies for conduit, tubing, and cable assemblies. This standard is intended for use by the electrical industry to provide guidelines for the manufacture and proper application of these products, and to promote the benefits of repetitive manufacture and widespread product availabilit
40、y. One of the primary purposes of this Standards Publication is to encourage the manufacture and utilization of products, which, in themselves function in accordance with this standard. While some sections of this publication are intended to eliminate misunderstandings between manufacturers and user
41、s, all sections when applied properly, contribute to safety in one way or another. The proper manufacture of fittings, cast metal boxes, and conduit bodies is however, only one consideration in promoting the safe use of electricity. Other safety considerations involve the joint efforts of the system
42、 designer, the various equipment manufacturers, the installer, and the user. Information is provided in this standard and in NEMA Standards Publications FB 2.10 and FB 2.20 to assist in proper selection and use. The following factors are vital in a safe electrical system and should be considered by
43、the user in the selection and application of equipment covered by the publication: a. Environmental conditions b. System design c. Equipment selection and application d. Installation e. Operating practices f. Maintenance This Standards Publication has been promulgated with a view of promoting safety
44、 to persons and property when products conforming with it are selected, installed, and maintained in accordance with the National Electrical Code. NEMA Standards Publications are periodically reviewed to meet changing conditions and technical progress, and the latest edition shall be utilized. Comme
45、nts from the users of this Standards Publication are welcome, and should be sent to: Vice President, Engineering National Electrical Manufacturers Association 1300 North 17th Street, Suite 1847 Rosslyn, VA 22209 At the time of publication, the member companies of the Conduit Fittings Section are as
46、follows: Adalet, A Scott and cast metal Junction Boxes, Pull Boxes, and covers. This standard does not include standard conduit couplings of the type provided with lengths of Rigid and Intermediate Metal Conduit, or threaded conduit nipples, or threaded or unthreaded factory made bends derived from
47、Rigid and Intermediate Metal Conduit or Electrical Metallic Tubing. This standard does not apply to boxes or enclosures or explosion-proof and dust-ignition proof fittings specifically designed for use in hazardous (classified) locations. Exceptions are those ordinary location fittings and enclosure
48、s which are specifically permitted by the National Electrical Code in Class I, Division 2, and Class II and III Hazardous (classified) locations. 1.2 NORMATIVE REFERENCES Unless otherwise stated, references are to the latest edition of the standard. American National Standards Institute (ANSI) 11 West 42nd Street, 13th Floor New York, NY 10036 ANSI C80.1 Specification for Zinc Coated Rigid Steel Conduit ANSI C80.3 Steel Electrical Metallic Tubing ANSI C80.5 Electrical Rigid Aluminum Conduit ANSI C80.6 Electrical Int