Libro de tranmision y distribucion

UNITED STATES DEPARTMENT OF AGRICULTURE Rural Utilities Service

BULLETIN 1724E-153

SUBJECT: Electric Distribution Line Guys and Anchors TO: RUS Electric Borrowers and RUS Electric Staff EFFECTIVE DATE: Date of Approval OFFICE OF PRIMARY INTEREST: Distribution Branch, Electric Staff Division FILING INSTRUCTIONS: This bulletin replaces REA Bulletin 61-5, “Guide for the Design of Guys andAnchors for Grade C Distribution Construction,” and Chapter V-5 of REA Bulletin 160-2, “Mechanical Design Manual for Overhead Distribution Lines.” Discard Bulletin 61-5. File this new bulletin with 7 CFR 1724. AVAILABILITY: This bulletin is available on the Rural Utilities Service website at page at http://www.usda.gov/rus/electric/index.htm. PURPOSE: This guide bulletin provides informationneeded to properly design guying for conductors attached to wood distribution poles. To this end, the bulletin contains data, equations, and sample calculations. The bulletin also contains information regarding standard RUS anchor and guying assemblies and their component parts to assist the user in the proper selection and installation of these assemblies.

April 25, 2001________________________
Blaine D. Stockton Assistant Administrator Electric Program

___________
Date

Bulletin 1724E-153 Page 2 TABLE OF CONTENTS
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Introduction ...................................................................................................................... 4 Anchors, Anchoring, and Soils........................................................................................ 5 Guy Wires ......................................................................................................................... 7 RUS Guy Assemblies and Hardware.............................................................................. 7 Loading on Poles and Guy Assemblies........................................................................... 9 NESC (1997 Edition) Guying Requirements ............................................................... 11 Determine Weakest Component Part........................................................................... 11 Installation of Guy and Anchor Assemblies................................................................. 11 Equations for Loading Moments onPole..................................................................... 13 Calculation of Horizontal Loads on Guy Assemblies.................................................. 14 Calculation of Permitted Loads on Guy Assemblies ................................................... 15 Calculation of Minimum Guy Lead.............................................................................. 17 Methodology for MultipleGuys .................................................................................... 18 Example Guy Assembly Calculation ............................................................................ 18 Determination of Pole Class to Support Vertical Loads ............................................. 22

Exhibit A: Conductor Loadings (1997NESC)......................................................................... 27 Exhibit B: Extreme Wind Loadings (1997 NESC) ................................................................. 28 Exhibit C: Contributors............................................................................................................. 29

TABLE OF TABLES Table 2-1: RUS Standard Distribution Anchor Assemblies .........................................5 Table 2-2: Soil Classifications .......................................................................................... 6 Table 3-1: Guy Wire Strength Data ................................................................................ 7 Table 4-1: RUS Guying Assembly Units......................................................................... 8 Table 4-2: Standard Washers – Loads...