Item 18: Rule Change re Overhead Distribution Line Clearance — original pdf

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Overhead Distribution Line Clearance Rule Change Item 18 Briefing to the Electric Utility Commission Scott Bayer, P.E., Director Transmission & Distribution Engineering Electric System Engineering & Technical Services 21th of June 2021 © 2018 Austin Energy Agenda • New & Previous Clearance Requirements • Drivers of Change & Examples • Benchmarked Clearances • Rule Making & Appeal Processes 2 Previous Clearance Envelope Compared to Current Previous Current 3 Minimum Industry Standards • NESC provides “minimum” clearance distances • 7.5’ horizontal for 750V to 22kV • 12.5’ to 18.5’ vertical (depending on accessibility by pedestrians, vehicles, trucks) • OSHA 1910.333 provides minimum radial distance for unqualified workers (non electric utility workers) to perform work adjacent to energized conductors • 10’ for 12.5 kV 4 Drivers of Clearance Change • Buildings built 7.5’ from 12,470 volts do not allow for unqualified workers to perform the construction or maintenance of that building • After developer/contractor completes construction, electrical hazard may exist to (un- informed) owner when performing maintenance • Austin Energy’s new 15’ Radial Clearance Rule was developed from: • 10’ OSHA Unqualified Worker Clearance • This includes the 7.5’ NESC Minimum Distance • 5’ Allowance for Scaffolding, Material Handling • Past history of non-compliant construction including fatality of non-qualified worker • >70 Notice of Electrical Hazard issued since 2017 • Zoning changes have led to a proliferation of ADUs which have significantly reduced workspace and access to lines & poles for Austin Energy linemen 5 Overhead Electric Distribution Clearance Violations Building meets 7.5’ AE clearance requirement but scaffolding erected within 10’ OSHA clearance & 5’ from energized primary 6 Overhead Electric Distribution Clearance Violations New structure built within the 7’6” horizontal clearance of primary and neutral conductors. 7 Overhead Electric Distribution Clearance Violations Encroachment into the 10’ radial clearance during construction. 8 Overhead Electric Distribution Clearance Violations Scaffolding erected by contractors using 2x4’s to push the primary out of the way. Customer’s contractors worked within the minimum approach distance which resulted in an electrocution fatality. 9 Other Utility Clearance Requirements (Clearance from buildings @ 750V to 22kV) Austin Energy (City Owned) CPS (City Owned) Bluebonnet (Cooperative) PEC (Cooperative) 7.5’ horizontal (NESC 234) 10.5’ horizontal from conductor 15’ from pole (no buildings or other sky to ground) 10’ horizontal for 1 phase line, 15’ horizontal for 3 phase lines No building within 7.5’ vertical (sky to ground) 13.5 to 19.5 vertical (depending on accessibility by pedestrians, vehicles, trucks) May require 20’ from pole for 3 phase 15’ radius around primary and neutral 20’ easement on 3ph lines No published clearance tables 20’ easement on 1phase lines (no building within easement) 30’ easement (No building within easement) 30’ easement on 3phase lines (No building within easement) 10 AE Development & Stakeholder Notices Other City Departments Review 30 day public comment period 30 day public appeal period Rules Adoption Timeline Stakeholder Outreach for 2Q Process: • • • • 1/12/21 - Customers notified and invited to DCM proposed changes meeting 1/22/21 - Customer meeting and discussion of DCM proposed changes 2/8/21 - AGC Meeting – presented upcoming clearance update to attendees 5/3/21 - Received and replied to customer review comments 11 Appeal Process • Appeal made in writing within 30 days of posting • City Clerk provides appeal to: • City Manager • Director of the Department adopting the rule • Each City Council member • Appealed rule may not be enforced until City Manager’s decision • City Manager may affirm, amend or withdraw the appealed rule • City Manager has 60 days for decision; if no decision, then the rule is withdrawn 12 Confidential & Proprietary ©2018 Austin Energy. All rights reserved. Austin Energy and the Austin Energy logo and combinations thereof are trademarks of Austin Energy, the electric department of the City of Austin, Texas. Other names are for informational purposes only and may be trademarks of their respective owners.