SEPTEMBER 4 - 6, 2019
Third Party Antenna Mounting on Lattice Steel and Monopole Towers
Sergio Arambula – Southern California EdisonJeffery Collins, P.E. – Southern California Edison
SEPTEMBER 4 - 6, 2019
AgendaIntroductionAntenna TechnologySCE Assets and InfrastructureAntenna Project OverviewStructural AnalysisSite ConstructionIndustry Practices ConclusionQuestions
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Antenna Technology Created in 1997 Wireless Carriers
T-Mobile (MetroPCS/Cingular) AT&T Verizon Clearwire Sprint (Nextel)
Macro Site Equipment Antennas Radios (RRUs) Surge Protectors Diplexers/Combiners
1997
2019
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Antenna Technology 850 total macro sites 1997-2010
60 macro sites per year 2013-Present
170 macro sites per year 90% MODS, 10% new builds
2018 280 total macro sites 400 macro sites for 2019
Future Forecast Growth and expansion New Technologies, New
Communities
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Southern California Edison’s Assets
SCE services the following: 15 million people 5,000 large businesses 280,000 small businesses 180 incorporated cities 15 counties 50,000 square miles
SCE Assets: 12,600 miles of transmission lines
91,300 miles of distribution lines
20,000 bulk power structures
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Antenna Project Overview
Edison Carrier Solutions (ECS) Site Walks Scheduled Zoning Drawings Published and Presented Responsible Engineer Analyzes Rejection, Approval, or Approval with MOD Steel Order Ends Project Life Cycle
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Structural Analysis – Manuals/Software
ASCE MOP 74 – Guidelines for Electrical Transmission Line Structural Loading – latest version
General Order 95 – Overhead Electrical Line Construction – latest version
ANSI/TIA-222 – Structural Standard for Antenna Supporting Structures and Antennas – latest version
SCE Wind Maps – SCE created wind loading zones
Power Line Systems software: PLS-CADD, PLS-Tower, and PLS-Pole –latest release
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Structural Analysis: PLS-CADD LiDar data for all major bulk 220kV and 500kV T/L In-situ Loads Used LiDar data vs. PLS-CADD Lite vs. Google Earth Data
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Structural Analysis: PLS-CADD
Weather Condition Wire Temp (°F)
Wind Prss./Vel. (psf)/(MPH)
Radial Ice (in.)
Ice Den. (lbs./ft3)
Wire Wind Ht. Adjust Model
Wire Gust Response Factor
GO-95 Light 25 8.0/55.9017 0 0 None None
GO- 95 Heavy 0 6.0/48.4258 0.5 57 None None
NESC Extreme Wind (CA)* 60 18.496/85 0 0 NESC 2012 NESC 2012
ASCE-74 Extreme Wind* 45 18.496/85 0 0 ASCE 74-2009 ASCE 74-2009
Insulator Swing** 25 8.0/55.9017 0 0 None None
*: Or, SCE line specific criteria based on meteorological study.**: Weather case for insulator swing check (compare swing before (creep) and after (initial).
Weather Criteria
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Structural Analysis: PLS-CADD
Weather Condition Over Load Factors
Tower Wind Area Factor
Structure Wind Model
GO-95 Light 1.5 1.5 Wind on FaceGO- 95 Heavy 1.5 1.5 Wind on FaceNESC Extreme Wind (CA)*
1.0 1.0 NESC 2012
ASCE-74 Extreme Wind* 1.0*** 1.0 ASCE 74-2009FGO-95 Grade A Crossing**
1.0 1.5 Wind on Face
Lattice Tower Loading Criteria
*: Or, SCE line specific criteria based on meteorological study.**: For crossing of limited access highways, exclude this criteria for tower not originallydesigned for GO 95 crossing. Use 1/3 total conductor phases broken.***: Towers less than 25 years services use OLF = 1.25
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Structural Analysis: TIA-222 Calculations
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Structural Analysis: PLS-Tower
Advance Tower Analysis and Design System (ATADS) previously used
Most common towers used on SCE’s bulk power system are designed using PLS-Tower
Responsible engineer checks model for modifications, adds clip angles
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Structural Analysis: A-Frame/Monopoles
Antennas mounted on both monopoles and A-Frames are not welded to the structure itself but are chained by mounting kits provided and specially designed by our vendors.
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Site Construction
One to Three Weeks to Complete for MODsUp to 5 Months to Construct New Sites 4 to 6 Weeks to Receive Steel Material Certified Electrical Workers Install Reinforcements Field Crews Install Cell Sites Final Project Approval Granted By RF Engineers Final Site Approval Granted by City Engineers
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A B C D
E F G H
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Industry Practices SCE mounts directly onto towers Antenna installations are always below
energized conductors SCE standards requires a certified
electrical worker if mounts are near or above the conductors
SCE requires workers to work from safe distances based on voltage levels
Installations are done from cranes Some utilities will mount antennas above
the conductors with the use of a steel mast
Outages must be taken for the installation to occur
Lineman and certified workers will climb the tower itself and hoist equipment
Some utilities have eliminated installation of antennas on higher voltages
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Conclusion
Antenna Technology SCE Infrastructure Antenna Project Process Structural Analysis Site Construction Industry Practices
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Questions?
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Thank you !
Sergio Arambula – Southern California EdisonJeffery Collins, P.E. – Southern California Edison