1、 Guide for Selecting Aerial Cable Messengers and Lashing Wires Publication # ICEA P-79-561-2013 2013 by INSULATED CABLE ENGINEERS ASSOCIATION, Inc. ANSI/ICEA P-79-561-2013 ANSI/ICEA P-79-561-2013 ICEA P-79-561 Guide for Selecting Aerial Cable Messengers and Lashing Wires Published by Insulated Cable
2、 Engineers Association, Inc. Post Office Box 1568 Carrollton, Georgia 30112, USA Approved by Insulated Cable Engineers Association, Inc.: 04/01/2013 Approved by ANSI: 10/14/2013 Copyright 2013 by the Insulated Cable Engineers Association, Inc. All rights including translation into other languages, r
3、eserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the international and Pan American Copyright Conventions. ICEA P-79-561-2013 NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the
4、 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 Insulated Cable Engineers Association, Inc. (ICE
5、A) 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 persons who have an interest in the topic covered by this publication. While ICEA administers the process an
6、d establishes rules to promote fairness in the development of consensus, 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 publications. ICEA disclaims liability for personal
7、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 reliance on this document. ICEA disclaims and makes no guaranty or warranty, expressed or implied, as
8、 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. ICEA does not undertake to guarantee the performance of any individual manufacturer or sellers produc
9、ts or services by virtue of this standard or guide. In publishing and making this document available, ICEA is not undertaking to render professional or other services for or on behalf of any person or entity, nor is ICEA undertaking to perform any duty owed by any person or entity to someone else. A
10、nyone using this document should rely on his or her own independent judgement 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 ava
11、ilable from other sources, which the user may wish to consult for additional views or information not covered by this publication. ICEA has no power, nor does it undertake to police or enforce compliance with the contents of this document. ICEA does not certify, test, or inspect products, designs, o
12、r 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 ICEA and is solely the responsibility of the certifier or maker of the statement. ICEA P-79-561-2013 i FOREWOR
13、D This guide publication for selecting aerial cable messengers, ICEA P-79-561, was developed by the Insulated Cable Engineers Association (ICEA). ICEA standards and guides are adopted in the public interest and are designed to eliminate misunderstanding between the manufacturer and the user and to a
14、ssist the user in selecting and obtaining the proper product for his particular need. Existence of an ICEA/NEMA Standard does not in any respect preclude the manufacture or use of products not conforming to the standard. The user of this Standard is cautioned to observe any health or safety regulati
15、ons and rules relative to the manufacture and use of cable made in conformity with this Standard. Requests for interpretation of this Standard must be submitted in writing to: Insulated Cable Engineers Association Post Office Box 1568 Carrollton, Georgia 30112 An official written interpretation will
16、 be provided once approved by ICEA. Suggestions for improvements gained in the use of this Standard will be welcomed by the Association. Page 16 (Figure 250-1 & Table 250-1) reprinted with permission from IEEE Std C2 2012 National Electrical Safety Code, Copyright 2011, by IEEE. The IEEE disclaims a
17、ny responsibility or liability resulting from the placement and use in the described manner. Pages 21, 22 and 23 (Chart A-2, Chart B-2 & Sag Tables) reprinted with permission from Copperweld Bimetallics, LLC.ICEA P-79-561-2013 ii CONTENTS Page FOREWORD i Section 1 GENERAL 1 1.1 SCOPE . 1 1.2 UNITS.
18、1 1.3 REFERENCES . 1 Section 2 MESSENGERS AND LASHING WIRES . 2 2.1 MESSENGER SELECTION . 2 2.2 MESSENGER CHARACTERISTICS . 2 2.3 MESSENGER AND LASHING WIRE SIZES . 2 2.4 LASHING WIRE LAY LENGTHS . 2 Section 3 SPAN LENGTHS . 3 3.1 RECOMMENDED MAXIMUM SPAN LENGTHS . 3 Section 4 SAG AND TENSION CALCUL
19、ATIONS 15 4.1 SAG AND TENSION CALCULATIONS FOR AERIAL CABLES . 15 4.2 ICE AND WIND LOADINGS 15 4.3 LOADING DISTRICT . 15 4.4 EXAMPLE SAG AND TENSION CALCULATIONS FOR FACTORY-ASSEMBLIED CABLE . 17 4.5 EXAMPLE SAG AND TENSION CALCULATIONS FOR FIELD-ASSEMBLED CABLE . 20 APPENDICES . 24 APPENDIX A 24 IC
20、EA P-79-561-2013 1 Section 1 GENERAL 1.1 SCOPE This guide has been prepared to facilitate the selection of messengers and lashing wires for both field- and factory-assembled, self-supporting aerial cables. The cables used for attachment to the messenger shall be suitable for the service and shall be
21、 manufactured and tested in accordance with the applicable ICEA Standards and installed in accordance with the applicable provisions of the National Electrical Code (NFPA-70) and/or the National Electrical Safety Code/ANSI Standards Publication No. C2. This guide does not cover all possible messenge
22、r configurations. Reference should be made to other publications for service drop and neutral supported applications. 1.2 UNITS In this guide, units are expressed in the English system. To convert from an English unit to the appropriate metric unit, multiply the value of the English unit by the appr
23、opriate number from the following table: From To Multipler inches (in) millimeters (mm) 25.4 ohms per 1000 feet (/1000) milliohms per meter (m/m) 3.28 square inch (sq in) square millimeter (mm2) 645thousand circular mils (kcmil) square millimeter (mm2) 0.5067 pounds per square inch (psi) kilopascals
24、 (kPa) 6.89 pounds per foot newtons per meter 14.61.3 REFERENCES See Appendix A for a complete list of referenced standards by title and date. ICEA P-79-561-2013 2 Section 2 MESSENGERS AND LASHING WIRES 2.1 MESSENGER SELECTION The type of messenger chosen for a particular installation normally depen
25、ds upon three major factors: a. Adequate tensile strength. b. Chemical and mechanical stability. c. Electrical characteristics. As the strength member of the aerial cable assembly, the messenger supports the conductors and may act as a shield against falling tree limbs. In some installations, the me
26、ssenger may also serve as a neutral or grounded conductor. Operating as a system neutral, a properly selected messenger can offer good conductivity for protection against lightning and surge currents. Special applications such as installations near chemical or paper manufacturing plants, oil refiner
27、ies or seacoast locations may require messengers and lashing wires of more corrosion resistant metals such as Class C coated galvanized steel or stainless steel. Lashing wires may also be covered for additional physical protection. 2.2 MESSENGER CHARACTERISTICS In accordance with the referenced ASTM
28、 Standards, the physical and electrical properties of six widely used messenger types and constructions are detailed in Tables 3-1 through 3-4. 2.3 MESSENGER AND LASHING WIRE SIZES Tables 3-5 and 3-6 present suggested messenger and lashing wire sizes based upon the total weight of the completed cabl
29、e assembly. 2.4 LASHING WIRE LAY LENGTHS The maximum recommended lashing wire lay lengths are listed below: Lay Length (inches) Multiplexed and Parallel Assemblies 10.0* Reverse Twist Cable 10.0* Binder tape or lashing wire. * Lashing wire only suggest a maximum of 5.0 0.5” if a binder tape is used.
30、 ICEA P-79-561-2013 3 Section 3 SPAN LENGTHS 3.1 RECOMMENDED MAXIMUM SPAN LENGTHS Tables 3-7 through 3-12 present the recommended maximum permissible span lengths allowed based on the aerial cable assembly weight. These data presume: a. A heavy loading district. b. A maximum sag at 60F of 1.667% of
31、the span length. c. A maximum tension at 60F of not more than 30% of the messenger minimum breaking strength. d. A maximum tension under loading at 0F of not more than 50% of the messenger breaking strength. Note: Span lengths shown in Tables 3-7 through 3-12 are for the specific installation condit
32、ions listed above. Other installation conditions will result in different span lengths.ICEA P-79-561-2013 4 Table 3-1 MESSENGER CHARACTERISTICS - PHYSICAL AND ELECTRICAL Messenger Size* & Number of Aluminum/Aluminum-Clad Strands Aluminum Conductors, Aluminum-Clad Steel Reinforced (ACSR/AW) Per ASTM
33、B549 Linear Density (lb/ft) DC Resistance 20C (ohms/1000) Rated Breaking Strength (lb) Area x Modulus (ae) x 106No. 4 AWG 3/4 No. 3 AWG 2/5 No. 1 AWG 2/5 No. 1/0 AWG 2/5 0.124 0.214 0.340 0.428 0.405 0.321 0.202 0.160 6130 11300 16500 19500 1.004 1.692 2.690 3.392 Aluminum-Clad Steel Per ASTM B416 N
34、umber & Size of Strands Linear Density (lb/ft) DC Resistance 20C (ohms/1000) Minimum Breaking Strength (lb) Area x Modulus (ae) x 1067 x 12 AWG 7 x 10 AWG 7 x 8 AWG 7 x 6 AWG 7 x 5 AWG 19 x 9 AWG 19 x 8 AWG 0.104 0.165 0.262 0.416 0.525 0.566 0.714 1.127 0.709 0.446 0.280 0.226 0.208 0.165 6301 1002
35、0 15930 22730 27030 34290 43240 0.8257 1.313 2.088 3.319 4.186 4.494 5.667 * Sizes are based on equivalent resistance to all aluminum conductors. ICEA P-79-561-2013 5 Table 3-2 MESSENGER CHARACTERISTICS-PHYSICAL Messenger Size & # of Strands 30% EHS Copper Clad Per ASTM B228 40% HS Copper Clad Per A
36、STM B228 Stainless Steel Type 316 (HS) Per ASTM A368 EHS Class A Zinc-Coated Steel Per ASTM A475 Linear Density (lb/ft) Min. Breaking Strength (lb) Area x Modulus (ae) x 106Linear Density (lb/ft) Min. Breaking Strength (lb) Area x Modulus (ae) x 106Linear Density (lb/ft) Min. Breaking Strength (lb)
37、Area x Modulus (ae) x 106Linear Density (lb/ft) Min. Breaking Strength (lb) Area x Modulus (ae) x 1061/4” 7X - - - - - - 0.135 8500 1.060 0.121 6650 0.871 5/16” 7X 0.204 9196 1.313 - - - 0.212 13200 1.665 0.205 11200 1.502 3/8” 7X 0.324 13890 2.088 0.324 10460 2.088 0.282 18000 2.217 0.273 15400 1.8
38、21 7/16” 7X 0.409 16890 2.633 0.409 12670 2.633 0.416 26000 3.234 0.399 20800 2.770 1/2” 7X 0.515 20460 3.319 0.515 15330 3.319 0.535 33700 4.190 0.517 26900 3.442 9/16” 7X 0.650 24650 4.186 0.650 18510 4.186 - - - - - - 9/16” 19X 0.700 30610 4.494 0.700 23390 4.494 0.670 36200 5.24 0.637 33700 4.38
39、3 5/8” 19X - - - - - - 0.855 47000 6.53 0.796 40200 5.36 21/32” 19X 0.883 37690 5.667 0.883 28380 5.667 - - - - - - 23/32” 19X 1.113 45850 7.146 1.113 34390 7.146 - - - - - - 3/4” 19X - - - - - - - - - 1.155 58300 7.72 13/16” 19X - - - - - - - - - - - - ICEA P-79-561-2013 6 Table 3-3 MESSENGER CHARA
40、CTERISTICS DC RESISTANCE AT 20C, OHMS/1000 Messenger Size & # of Strands 30% EHS Copper Clad(1) 40% HS Copper Clad(1) Type 316 Stainless Steel(2) EHS Class A Zinc-Coated Steel 1/4” 7X 5/16” 7X 3/8” 7X 7/16” 7X 1/2” 7X 9/16” 7X - 0.490 0.308 0.244 0.194 0.154 - 0.368 0.231 0.183 0.145 0.115 * - - - -
41、 - * - - - - - 9/16” 19X 5/8” 19X 21/32” 19X 23/32” 19X 3/4” 19X 13/16” 19X 0.144 - 0.114 0.090 - 0.072 0.108 - 0.086 0.068 - 0.054 - - - - - - - - - - - - *Data Unavailable. (1) Per ASTM B228. See Reference Number 5 in Appendix A. (2) Per ASTM A368. See Reference Number 3 in Appendix A. Table 3-4 C
42、OEFFICIENT OF LINEAR EXPANSION, X10-6PER DEGREE F Aluminum-Clad Steel ACSR/AW Copper-Clad Stainless SteelZinc-Coated Steel 7.2 8.0 7.2 8.8 6.4 ICEA P-79-561-2013 7 Table 3-5 MESSENGER & LASHING WIRE SIZES FOR MULTIPLE CONDUCTOR CABLE BASIS 150 FT. SPANS & SUPPORTS AT EQUAL ELEVATION* Linear Density
43、of Completed Cable Assembly Including Messenger & Lashing Wire (lb/1000 ft) Messenger Lashing Wire Size (inches) Size (inches) Number & Size of Wires Nominal Minimum Breaking Strength (lb) Diameter (inches) Linear Density (lb/1000 ft) Grade 30% EHS Copper-Clad Steel per ASTM B228 Copper 1670 or less
44、 1671 2450 2451 3700 3701 4500 4501 5450 5451 6560 6561 8150 8151 10030 10031 12200 - 5/16 3/8 7/16 1/2 9/16 9/16 21/32 23/32 3 x 8 AWG 7 x 10 7 x 8 7 x 7 7 x 6 7 x 5 19 x 9 19 x 8 19 x 7 0.277 0.306 0.385 0.433 0.486 0.546 0.572 0.642 0.721 139 204 324 409 515 650 700 883 1113 6282 9196 13890 16890
45、 20460 24650 30610 37690 45850 0.375 x 0.030 “ “ “ “ 0.500 x 0.040 “ “ “ Grade 40% HS Copper-Clad Steel Per ASTM B228 Copper 1845 or less 1846 2785 2786 3370 3371 4075 4076 4925 4926 6220 6221 7550 7551 9145 9146 11065 - 3/8 7/16 1/2 9/16 9/16 21/32 23/32 13/16 3 x 6 AWG 7 x 8 7 x 7 7 x 6 7 x 5 19 x
46、 9 19 x 8 19 x 7 19 x 6 0.349 0.385 0.433 0.486 0.546 0.572 0.642 0.721 0.810 220 324 408 515 649 700 883 1113 1403 6934 10460 12670 15330 18510 23390 28380 34390 41600 0.375 x 0.030 “ “ “ 0.500 x 0.040 “ “ “ “ Type 316 Stainless Steel Per ASTM B368 Stainless Steel 2040 or less 2041 3170 3171 4310 4
47、311 6230 6231 8040 8041 8620 8621 11180 1/4 5/16 3/8 7/16 1/2 9/16 5/8 7 x 0.083 in. 7 x 0.104 in. 7 x 0.120 in. 7 x 0.145 in. 7 x 0.165 in. 19 x 0.112 in. 19 x 0.125 in. 0.249 0.312 0.360 0.435 0.495 0.560 0.625 135 212 282 416 535 670 855 8500 13200 18000 26000 33700 36200 47000 0.375 x 0.025 “ “
48、“ 0.500 x 0.030 “ “ *Note - For Heavy Loading conditions, the messenger size must be checked using the procedure given under sag and tension calculations (See Section 4). ICEA P-79-561-2013 8 Table 3-6 MESSENGER & LASHING WIRE SIZES FOR MULTIPLE CONDUCTOR CABLE BASIS 150 FT. SPANS & SUPPORTS AT EQUA
49、L ELEVATION* Linear Density of Completed Cable Assembly Including Messenger & Lashing Wire (lb/1000 ft) Messenger Lashing Wire Size (inches) Size (inches) Number & Size of Wires Nominal Minimum Breaking Strength* (lb) Diameter(inches) Linear Density (lb/1000 ft) Aluminum Conductors, Aluminum-Clad Steel Reinforced (ACSR/AW) per ASTM B549 Aluminum 1630 or less 1631 3005 3006 4390 4391 5185 - - - - #4 AWG-3/4 #3 AWG-2/5 #1 AWG-2/5 #1/0 AWG-2/5 0.307 0.382 0.482 0.541 124 214 340 428 6130* 11300* 1
