NEMA PRP 5-2015 Installation Guidelines for Surface Nonmetallic Raceway.pdf

1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA PRP 5-2015Installation Guidelinesfor Surface NonmetallicRacewayNEMA Standards Publication PRP 5-2015 Installation Guidelines for Surface Nonmetallic Raceway Published by National Electrical Manufacturers Association 1300 Nor

2、th 17th Street, Suite 900 Rosslyn, VA 22209 www.nema.org 2015 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 Artistic Works, and the Inte

3、rnational and Pan American copyright conventions. 2015 National Electrical Manufacturers Association 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 devel

4、oped. Consensus does not necessarily mean that there is unanimous agreement among every person participating in the development of this document. NEMA standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards developmen

5、t 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 administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it

6、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 publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether spe

7、cial, indirect, consequential, 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, an

8、d 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 performance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and ma

9、king 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 any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judg

10、ment or, as appropriate, 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 additio

11、nal 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 does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other

12、 statement of compliance 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. NEMA PRP 5-2015 Page i 2015 National Electrical Manufacturers Association Foreword The purpose of th

13、ese guidelines is to describe the procedures and recommended practices for properly installing surface nonmetallic raceway (SNR) and SNR fittings. These guidelines are in no way intended to assume or replace any responsibilities of engineers, customer representatives, owners, or other persons in est

14、ablishing engineering design practices and procedures best suited to individual job conditions. The NEMA Polymer Raceway Products Section, through its members, works closely with such organizations as the National Electrical Contractors Association and others in the periodic review and revision of i

15、ts standards for any changes necessary to keep them up to date with evolving technology. Proposed or recommended revisions should be submitted to: Vice President, Industry Operations National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, Virginia 22209 These guideli

16、nes were developed and approved by the NEMA Polymer Raceway Section. At the time of approval, the Polymer Raceway Section consisted of the following members: Anamet Electrical, Inc http:/ Mattoon, IL AFC Cable Systems, a part of Atkore International New Bedford, MA Allied Tube and Conduit, a part of

17、 Atkore International Harvey, IL Champion Fiberglass, Inc. Spring, TX FRE Composites (2005) I St. Andre-dArgenteuil, PQ, Canada Hubbell Incorporated Shelton, CT IPEX Management Inc. Mississauga, ON, Canada Legrand North Americawww.legrand.us West Hartford, CT Panduit Corporation Tinley Park, IL Roya

18、l Building Products ShelbyTownship, MI Southern Pipe, Inc. www.southern-New London, NC Thomas it is recommended that the work described be performed by qualified persons familiar with standard electrical construction practices, electrical equipment, and safety of electrical wiring systems. 6.2 CUTTI

19、NG RACEWAY AND COVER SNRs insulative nature slows the dissipation of heat built up at the cutting interface. This can lead to localized melting or warping if excessive heat develops. Care must be taken to balance the feed rate with the cutting speed to avoid localized melting. Clearance in the cutti

20、ng area is also helpful in reducing heat NEMA PRP 5-2015 Page 3 2015 National Electrical Manufacturers Association build-up. The use of carbide-tipped blades is recommended because they last longer and produce more uniform cuts. For larger raceway sizes and large quantities of cuts, the following me

21、thods are suggested: a) Band saws: use a 0.020-0.025 inchthick blade having 14 teeth per inch (V-tooth edge). The blade material should be a hardened or tempered material. The saw should be operated at 4000-4500 feet per minute. The feed rate must compensate for the blade speed to avoid overheating.

22、 If localized melting occurs, either feed faster or slow the blade speed, if possible. Watch for dulling of the blade teeth. b) Table and circular saws: a blade with a diameter of 10-14 inches with a thickness of 0.110-0.120 inches is convenient for straight cuts. The blade should have 80-100 teeth

23、and a kerf of 0.125 in. For smaller raceway sizes, a hand-held cutting tool is recommended that typically can be obtained through a raceway manufacturer. A fine-tooth handsaw can also be used. 6.3 BENDING RACEWAY 1) Slide an 18-30inch section of the appropriate profile size raceway into a pipe heati

24、ng blanket (not offered by the raceway manufacturer) as shown in Figure 1. A recommended blanket size is one that is designed for bending a Trade Size -1 conduit. 2) Allow the raceway section to heat approximately 2-3 minutes, as shown in Figure 2. The raceway will be become soft and pliable but sho

25、uld not stretch. The heating time will vary with blanket temperature and raceway size. 3) Remove the raceway section from the blanket and hold it in the desired position until the raceway cools, as shown in Figure 3. Install mounting straps immediately. Figure 1 Raceway Insertion into Heat Blanket F

26、igure 2 Raceway Section in Heat Blanket Figure 3 Raceway Held in Mounting Position after Removal from Heat BlanketNEMA PRP 5-2015 Page 4 2015 National Electrical Manufacturers Association 6.4 SECURING AND SUPPORTING Surface nonmetallic raceway is intended to be mounted to the surface of a structure

27、and supported at intervals in accordance with the manufacturers installation instructions. A typical procedure is as follows: 1) Mount the raceway base to a wall using appropriate screws. Pan head screws or equivalent fasteners are recommended. For mounting a typical raceway base, snap a chalk line

28、on the wall that indicates the top of the raceway. Line up the top of one end of the raceway base, then screw it down to the wall. 2) Progressively install screws at the recommended minimum interval, starting from the screwed-down end while lining up the top of the raceway base with the chalkline. A

29、 level can be used instead of a chalkline to ensure that the raceway is straight. 3) Ensure that the raceway cover and raceway base seams do not line up. The cover should overlap the base seam by a minimum of 6 in. Consult the manufacturer for the appropriate securing method for the substrate to whi

30、ch the raceway is being secured. 6.5 FITTINGS AND BOXES An example of a complete range of fittings would include flat, internal and external elbows, tees, entrance fittings, cover clips and end caps. These overlap the cover and base to hide any uneven cuts. All fittings include a base, where applica

31、ble to eliminate mitering. A complete line of full-capacity corner elbows is needed to maintain a controlled cable bend radius meeting the specifications of TIA/EIA 569. Transition or reducer fittings are also available to adapt to other sizes and types of raceway. Device mounting brackets are insta

32、lled for mounting standard devices in-line or offset from the raceway. Device brackets typically can provide up to four single-gang openings at one location. Faceplates should fit flush in the device plate. Similarly, device boxes are also available for mounting standard devices and faceplates and a

33、re available in single- and two-gang configurations. Adhesive on the back of the device box is intended to be used as an installation aid for positioning the product, not as a means of permanent support. For applications with power wire, appropriate screw fasteners must be used in addition to the ad

34、hesive. For applications with only communication cable, screw fasteners are recommended in addition to the adhesive. NEMA PRP 5-2015 Page 5 2015 National Electrical Manufacturers Association A typical installation procedure is as follows: 1) Notch the proper knockout-breakout tab in the base and cov

35、er using a knife (see figures 4 and 5). Use pliers to remove knockout-breakout tabs inward for a cleaner edge. Trimming might be necessary. 2) Fasten the device box base to the wall using fasteners appropriate for the substrate (consult the manufacturer for recommended fasteners, if not provided). 3

36、) Attach the box cover onto the box base. 4) Mount the device (receptacle) and the faceplate (see Figure 6 for complete assembly pertaining to installation steps 2-4). Figure 4 Removal of Box Cover Breakout Tabs Figure 5 Removal of Box Base Breakout Tabs Figure 6 Assembly of Box Base, Cover, Recepta

37、cle, and Faceplate NEMA PRP 5-2015 Page 6 2015 National Electrical Manufacturers Association 6.6 ELBOWS 6.6.1 Cover Only For elbows consisting of a cover only, install as follows (see figures 7-9): 1) Cut the SNR base 45 with a miter cutting saw. 2) Snap the elbow fitting into place over the miter c

38、ut raceway base. Figure 7 Flat Elbow CoverRaceway Base Miter Cut Figure 8 Internal Elbow CoverRaceway Base Miter Cut Figure 9 External Elbow CoverRaceway Base Miter Cut NEMA PRP 5-2015 Page 7 2015 National Electrical Manufacturers Association 6.6.2 Base and Cover For elbows consisting of a base and

39、cover, install as follows (see figures 10-12): 1) Cut the raceway base and cover straight across. 2) Align the elbow base with adjacent raceway base sections. 3) Drill and fasten the elbow base to the wall. 4) Ensure that the fitting covers are positioned according to the manufacturers instructions.

40、 Figure 10 Flat Elbow Base and Cover Figure 11 Internal Elbow Base and Cover Figure 12 External Elbow Base and Cover NEMA PRP 5-2015 Page 8 2015 National Electrical Manufacturers Association For a tee fitting, install as follows (see Figure 13): 1) Remove the knockouts and appropriate openings from

41、the tee base, as necessary, to make room for the raceway base. As required by the NEC and the CE Code, Part I, data and communication circuits must be separated from lighting and power circuits. 2) Snap the tee base to the raceway base, and fasten with fasteners as described in the manufacturers ins

42、tructions. 3) Align and fasten the raceway to the adjacent end of the tee base. 4) Snap on the raceway covers, then snap on the tee cover. 5) For disassembly, insert a screwdriver or appropriate tool in the location shown, or refer to the manufacturers instructions. Figure 13 Tee FittingBase and Cov

43、er NEMA PRP 5-2015 Page 9 2015 National Electrical Manufacturers Association 6.7 INLINE DEVICE BOX BASE AND COVER For an inline device box, install as follows (see Figure 14): 1) Align the device box base with adjacent raceway base sections. 2) Fasten the device box base with four fasteners, or as d

44、escribed in the manufacturers instructions. As required by the NEC and the CE Code, Part I, data and communication circuits must be separated from lighting and power circuits. Therefore, channel barriers must be installed in the device box base unless the base contains circuits allowed together in a

45、ccordance with the NEC and the CE Code, Part I. 3) Fasten the device to the base posts in the device box base. 4) Fit the raceway cover to the device box fitting base. 5) Snap the device box fitting cover to the device box fitting base. 6) Fasten the faceplates. Figure 14 Inline Device Box FittingBa

46、se and Cover NEMA PRP 5-2015 Page 10 2015 National Electrical Manufacturers Association 6.8 RAISED DEVICE BOX BASE AND COVER For a raised device box, install as follows (see Figure 15): 1) Remove knockouts on the base as required for device wiring. 2) Snap the device box fitting base onto the racewa

47、y base. 3) Fasten the device to the base posts. 4) Fit the raceway cover to the device box fitting base. 5) Snap the box fitting cover onto the device box fitting base. 6) Fasten the faceplates. Figure 15 Raised Device BoxBase and Cover NEMA PRP 5-2015 Page 11 2015 National Electrical Manufacturers

48、Association 6.9 TRANSITION FITTINGS 6.9.1 Conduit TransitionBase and Cover For transitioning from conduit to surface raceway, install as follows (see Figure 16): 1) Remove knockouts and openings, as required, for back feed or end feed. 2) Remove appropriate openings for raceway or a suspended ceilin

49、g grid, as required. 3) Fasten the adapter base using appropriate fasteners for the surface material. 4) Fasten the raceway base to the adapter base. NOTEThe removable channel divider must be installed into the adapter base, unless the channels contain circuits that are not required to be separated, in accordance with the NEC. 5) Snap o