《NEMA-OS-2-2003.pdf》由会员分享，可在线阅读，更多相关《NEMA-OS-2-2003.pdf（44页珍藏版）》请在三一文库上搜索。
1、 ANSI/NEMA OS 2 ANSI/NEMA OS 2 NONMETALLIC OUTLET BOXES, DEVICE BOXES, COVERS, AND BOX SUPPORTS Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permit
2、ted without license from IHS -,-,- Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permitted without license from IHS -,-,- Approved as an American Na
3、tional Standard ANSI Approval Date: July 23, 2003 NEMA Standards Publication OS 2-2003 Nonmetallic Outlet Boxes, Device Boxes, Covers, and Box Supports Published by National Electrical Manufacturers Association 1300 North 17th Street, Suite 1847 Rosslyn, VA 22209 www.nema.org Copyright 2003 by the N
4、ational Electrical Manufacturers AssociationAll rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention or the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions. Copyright Nationa
5、l Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permitted without license from IHS -,-,- NOTICE AND DISCLAIMER The information in this publication was considered techn
6、ically 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 agreement among every person participating in the development of this document. The National Electrical Manufactu
7、rers Association (NEMA) standards and guideline 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 cove
8、red 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 independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgme
9、nts 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, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or
10、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 makes no warranty that the information in this document will fulfill any of your particular purposes or needs.
11、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 available, NEMA is not undertaking to render professional or other services for or on behalf of any person o
12、r 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 appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any give
13、n 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 information not covered by this publication. NEMA has no power, nor does it undertake to police or enforce complia
14、nce 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 compliance with any health or safety related information in this document shall not be attributable to NEMA and i
15、s solely the responsibility of the certifier or maker of the statement. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permitted without license from
16、 IHS -,-,- OS 2-2003 Page i Copyright 2003 by the National Electrical Manufacturers Association. CONTENTS Page Foreword .iv Section 1 GENERAL 1.1 Scope.1 1.2 Normative References.1 1.3 Definitions1 Section 2 GENERAL STANDARDS 2.1 Material4 2.2 Corrosion Protection4 2.3 Screws.4 2.4 Openings .4 2.4.1
17、 Cable-Size Knockouts4 2.4.2 Knockouts for Conduit or Tubing5 2.4.3 Clamps .5 2.5 Supports 5 2.6 Boxes for Supporting Equipment or Accessories5 2.6.1 Boxes for Luminaire Support6 2.6.2 Boxes for Ceiling-Suspended Fan Support6 2.7 Device Boxes.6 2.8 Boxes and Mounts for Other Devices and Accessories6
18、 2.9 Boxes for High and Low Voltage Circuits6 2.10 Marking6 2.10.1 General.6 2.10.2 Boxes for Supporting Equipment and Accessories6 2.10.3 Cable Clamps.6 2.11 Grounding6 Section 3 SPECIFIC REQUIREMENTS 3.1 General7 3.2 Index to Figures.7 Tables Table 2-1 SCREWS COMMONLY USED IN CONJUNCTION WITH OUTL
19、ET BOXES, DEVICE BOXES, AND COVERS4 Table 2-2 DIAMETER OF KNOCKOUTS5 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permitted without license from IH
20、S -,-,- OS 2-2003 Page ii Copyright 2003 by the National Electrical Manufacturers Association. Foreword The purpose of this Standards Publication is to provide a guide for the types and sizes of nonmetallic boxes and supports that are in general use. The standards present dimensional data needed for
21、 the safety and convenience of interchangeability with associated equipment. All items, when properly installed and properly used, contribute to safety. Properly manufactured boxes and covers are, however, only one factor in minimizing the hazards, which may be associated with the use of electricity
22、. The reduction of hazards involves the joint efforts of various equipment manufacturers, the system designer, the installer, and the user. Information is provided herein to assist users and others in the proper selection of boxes and covers. The manufacturer has limited or no control over the follo
23、wing factors, which are vital to a safe installation: a. Environmental conditions b. System design c. Equipment selection and application d. Installation e. Operating practices f. Maintenance This publication is not intended to instruct the user of the boxes and covers with regard to these factors,
24、except insofar as suitable equipment to meet needs can be recognized in this publication. These standards are necessarily limited to defining the construction requirements for the products covered herein. The publication has been promulgated with a view towards reducing the hazard to persons and pro
25、perty when boxes and covers conforming with these standards are properly selected and installed in accordance with the National Electrical Code. This Standards Publication has been reviewed with input obtained from independent testing laboratories and major consumer representatives. The publication
26、will be reviewed periodically by the Outlet and Switch Box Section of NEMA so that it will be kept up to date with advancing technology. Comments are welcomed and should be sent to: Vice President, Engineering National Electrical Manufacturers Association 1300 North 17th Street, Suite 1847 Rosslyn,
27、VA 22209 OS 2-2003 revises and supersedes OS 2-1998. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permitted without license from IHS -,-,- OS 2-200
28、3 Page iii Copyright 2003 by the National Electrical Manufacturers Association. This Standards Publication was developed by the Outlet and Switch Box Section. Section approval of the standard does not necessarily imply that all section members voted for its approval or participated in its developmen
29、t. At the time it was approved, the Outlet and Switch Box Section was composed of the following members: Allied Moulded Products, Inc.Bryan, OH Arlington Industries, Inc.Scranton, PA Bowers, A Subsidiary of Thomas cabinets or cutout boxes; floor boxes; flush device cover plates; boxes, plates, and c
30、overs designed for use with surface metal or surface nonmetallic raceway systems only; and boxes larger than 1650 cm (100 cu. in.) in volume, except multiple gang device boxes. 1.2 NORMATIVE REFERENCES The following publications are adopted in part, by reference in this publication, and are availabl
31、e from the organizations below. Unless otherwise noted, references are to the most recent edition. National Electrical Manufacturers Association 1300 North 17th Street, Suite 1867 Rosslyn, VA 22209 NEMA OS 3 Selection and Installation Guidelines for Electrical Outlet Boxes National Fire Protection A
32、ssociation Batterymarch Park Quincy, MA 00269 ANSI/NFPA 70 National Electrical Code Underwriters Laboratories, Inc. 333 Pfingsten Road Northbrook, IL 60062 ANSI/UL 514C Standard for Nonmetallic Outlet Boxes, Flush Device Boxes and Covers 1.3 DEFINITIONS blank cover: An outlet box cover having no kno
33、ckouts or openings, other than those used to mount to a box. These covers complete the enclosure. blank/knockout cover: An outlet box cover that contains a knockout which can be removed to accommodate a fitting for a pendant cord, etc. When left in place it may serve as a blank cover. box (electrica
34、l): Part of an enclosure provided with means for mounting a cover, cover-plate, accessory, etc. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permit
35、ted without license from IHS -,-,- OS 2-2003 Page 2 Copyright 2003 by the National Electrical Manufacturers Association. box extender: An accessory installed in or on a box that is mounted in a finished structure. The box extender rests on the edge of the existing box (fixed depth) or extends into t
36、he box (adjustable depth). It is not mechanically secured to the box. The flange of the box extender, if provided, rests on the finished surface. box support: A means (e.g. bracket) for securing an outlet or device box to the building structure or finished surface. Supports can be an integral part o
37、f the box, attached to the box, or entirely separate. bracket: A box support for securing an outlet box or device box in place in walls or ceilings, or to wall studs, building structures, or structural members. cable box: An outlet box typically provided with clamps for use with metallic or nonmetal
38、lic cables or flexible nonmetallic tubing, or any combination of said cables and tubing. (See outlet box.) clamp: A part of or an accessory to a cable box to secure flexible nonmetallic tubing (Loom) or cable to the box. concrete box: An outlet box especially intended for support in concrete, typica
39、lly constructed to allow end-to-end extension and the application of covers on two sides. This box is not intended for floor installation. conduit box: An outlet box designed with circular knockouts for conduits or fittings. device box: A box which is designed to receive and support switches, recept
40、acles, and similar devices. The term “device box” includes the following specific types: a. Single gangfixed sides, accommodates a single device b. Two gangfixed sides, accommodates up to two devices c. Three gangfixed sides, accommodates up to three devices d. Four gangfixed sides, accommodates up
41、to four devices e. Gangablepermits the removal of one or both sides of the box to join (or gang) as many sections as required device mounting covers: A device box cover that provides a mounting platform for a wiring device. The device is mounted on top of the cover. The cover may be raised. These co
42、vers are also sometimes referred to as mud rings. A wallplate is required to complete the enclosure. exposed work cover: A device box cover that is typically raised having cutouts to accept and support wiring devices. The devices are mounted to the underside of the cover. These covers also complete
43、the enclosure. flush-mounted box: A box that is so designed as to have a minimal front projection from the surface surrounding the box opening. hung-ceiling box: A box that consists of a ring and a back plate with supporting bars for use with rigid nonmetallic conduit, electrical nonmetallic tubing,
44、 flexible nonmetallic tubing, or nonmetallic sheathed cable above suspended ceilings. junction box: A junction box with a volume of 100 cu. in. or less is considered an outlet box. knockout: A portion of the wall of a box that can be removed readily in order to provide an opening for the entry of tu
45、bing, conduit, or cable. listed: Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or ma
46、terials or periodic evaluation of services, and Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 05:32:25 MDTNo reproduction or networking permitted without license from IHS -,-,- OS 2-2003 Pag
47、e 3 Copyright 2003 by the National Electrical Manufacturers Association. whose listing states that the equipment, material, or services either meets appropriate designated standards or has been tested and found suitable for a specified purpose. outlet box: a box used in an electrical wiring system f
48、or containing wire, taps, splices, or devices. It has provisions for the entry of conduit, tubing, or cable assemblies and for the attachment of a separate cover, which is used to close the box or provide support for the devices or fixtures. NOTEThe function of an outlet box, when completely closed by a cover or part of a wiring device acting as a cover, is to guard live parts against outside incidental contact, to protect the surrounding environment from faults occurring within the outlet box, to permit inspection of the wiri