Nelson Hydro Downtown Conversion July 26, 2010 Project Overview

Introduction –This project consists of upgrading the electrical distribution system in the City of Nelson downtown core, –The existing lane structures have overhead primary and secondary lines, and transformation mounted on poles and overhead platforms, –These will be replaced with a system having overhead secondary lines, underground primary lines, and pad mounted transformers, –The primary supply voltage will be changed from 4 kV to 25 kV.

Hydro T&D Upgrades The Downtown Conversion is part of the Long Term Hydro T&D Upgrade plan: Transmission line upgrades (nearly complete), Voltage conversions (Front St. 2009, Downtown 2010/11, Uphill 2012), Rosemont Sub rebuild (2010/12), We are about mid way through this plan: Completion of the Downtown Conversion and the Rosemont substation upgrade will move us close to completion.

Project Need –The Downtown distribution needs to be upgraded for several reasons: 1.The pole structures are at the end of their service life, 2.Upgrading the distribution voltage will improve logistics, and help move towards retiring the City Substation at Victoria and Josephine Streets, 3.Due to age and damage the structures are concerns for safety, 4.Moving to 25 kV distribution will result in a reduction of distribution losses.

Project Need

Scope of Project

Scope of Project Pole Replacement

Other Benefits The new design will have fewer conductors running down the Lanes. This will allow: Single pole structures instead of two pole structures – provides more free space at ground level, and easier access to parking areas, Fewer wires and no transformers in the air will have a tidier appearance, Improved electrical service reliability in the downtown area, Improved lane way lighting, The upgraded distribution voltage provides better ability to serve new / changing loads downtown.

Design Details New structures will be a single pole line with wire arranged vertically. (Existing arrangement uses two pole structures with a combination of horizontal and vertical wire configurations), Secondary circuits (customer voltage) will run overhead down the lanes. (Existing design also does this), Primary circuits (distribution system) will be in underground ducts running beneath the streets. (Existing system has these primary circuits overhead in the lanes), Transformers will be located on ground level islands where each island will feed roughly 1 block. (Existing system has multiple overhead transformer banks mounted on poles and platforms).

Design Details – Pad Mount Transformers Before 400 Block Kootenay Street After 400 Block Kootenay Street

Design Details – Lane Lines Existing Structures New Structures

Cultural & Decorative The CDC has proposed that they be tasked with decorating the transformer island with a cultural theme. This will include placing the history of Nelson Hydro on several of the transformers, and keeping several transformers for other cultural themes. We would like to install new lighting in the lanes with a historic theme. Costs for the lamp fixtures similar to the style used on Baker street are exorbitant. We are continuing to look for an option that has a more historical theme than the existing fixtures but has reasonable cost.

Customer Impacts Construction in lanes and streets. This will mean inconveniences due to restricted parking, some limited access for deliveries, and typical construction site hazards and delays, Power outages during the switch over to the new system in These outages will be kept to a minimum, and will be of short duration, There will be a time where two sets of poles will obstruct the lanes. Both the existing and new structures must be in place in order to keep the conversion outage time to a minimum, Street paving and sidewalk repair will occur after the civil construction.

Project Schedule 2009 /10: Acquire Materials Aug 2010: Install New Poles in Lanes Sep 2010: Commence Civil Works (ducts, transformer pads) Spring 2011: Electrical Installation (underground and overhead lines) Summer 2011: Move customers over to new system Fall 2011: Telus and Shaw transfer to new poles 2011/12: Remove old infrastructure (two pole structures, & wire)

Nelson Hydro Downtown Conversion