Contact Voltageat

Toronto Hydro

Detection, Mitigation, Prevention

Presented by:

Ben La Pianta , P.Eng., MBAVice PresidentDistribution Grid Management

2009 Jodie Lane National ConferenceStray Voltage Detection, Mitigation & Prevention

Agenda

• Toronto Hydro-Electric System – Company Overview

• Contact Voltage at Toronto Hydro – A Historical Perspective

• Contact Voltage - Emergency Declaration Level III

• Technical Summary - Assessment, Diagnosis, Challenges

• Moving Forward – Our Asset Management Plan

• Summary

• Closing

• Q&A

Company Overview

Toronto Hydro service territory: • Approximately 688,000 customers

Transmission

Generation

Distribution

HydroOne

Ontario Power

Generation & Others

TorontoHydro

Local Distribution Companies (LDCs) such as Toronto Hydro manage their local infrastructure and

have the direct relationship with customers

Electricity in Ontario:Where we fit in

About Toronto Hydro-Electric System

• Largest municipal utility in Canada 

• 688,000 Business and Residential Customers in the City of Toronto

• Distributes 18% of electricity in the Province of Ontario

• Summer‐peaking utility (System Peak 5000 MW)

• Designs and delivers Conservation and Demand Management programs that support a provincial call to create a “Culture of Conservation”

Toronto Hydro CorporationCorporate Structure

Board of Directors

Board of Directors

97% of revenueElectricity Distribution Conservation & Demand ManagementRenewable Generation(Green Energy Act)

3% of revenue Energy Services to the CityStreet LightingCity of Toronto Renewable Generation

Toronto Hydro-Electric System Toronto Hydro Energy Services

Board of Directors

Toronto Hydro Corporation

Strategic Focus

Customer Service Customer Service

Contact Voltage at Toronto Hydro A Historical Perspective

Historical Perspective

Prior to fatal shock incident in NYC (2004)

Frequency & impact of shocks very, very lowNo preventative maintenance to address CV Shocks were treated as isolated incidentsNot perceived to be a systemic concernStill the case in many situations and jurisdictions

Historical Perspective

Post fatal shock incident in NYC (2004)

Increase legislative burden, proof of ‘due diligence’Increase in regulatory intervention/awarenessTriggered wide scale media attentionErosion of public trustCreated industry focus on the issue of CVTriggered formation of Working Groups (IEEE, EPRI)

Genesis for the creation of “Jodie Lane Conference”

Historical Perspective

January 29/09 – Five School children shocked

January 13/09 – 2nd Dog fatally shockedNovember 20/08 – 1st Dog fatally shocked

January 30/09Declared Level III Emergency

January 29/09 – Engage Ontario Regulator

January 09 – Engaged PSC to scan for CV

2007 – Dog sustains shock from handwell2007 – Pedestrian shocked by bridge handrail

2006 & prior – no known records of CV incidents

Contact Voltage Emergency Response Level III

Mobilization

Declared highest level of emergency (Level III – Jan 30/09)

Activated Incident Command Centre(s)

Seized control of affiliate assets (street light system)

Labour Relations – clarify expectations i.e. "all hands on deck”

Suspended all ‘non-emergency’ work

Communication – Shareholder, Agencies, Customers, Ratepayers, Media

Increased scanning resources

Jan 30/31 – Begin mobilization of people, materials, equipment

Feb 1–28 – Inspected/repaired/replaced handwells/ SL poles

Emergency Response Objectives

Ensure worker and public safety (“make safe”)Fast & Visible Mobilization (within 3 days)Simple 3 step field execution process

Identify & remediate

unsafe equipment

1Define defective equipment for follow-up work

2

+ + Collect condition data and test

new standards

3

Scan entire City of TorontoManage expectations (regulator and public) Complete effort within 30 daysIndentify immediate follow-up work (define next steps)

What Was Accomplished

Handwells Inspected 11,765

Poles Inspected 39,821

# of calls reporting contact voltage 268

Individual Pieces of Material/Equipment

Purchased160,000

Number of Maps Used 1,543

People Involved >1,200

Total Hours Spent 98,401 Cost > $14 M

CV Events by Asset Owner

Customer reported events where TH or the Contractor have found no CV

Total CV events approximately 1600 (1350 from scan, 250 from inspection)

Contact Voltage Histogram

1074

198106

40 42 17 18 7 2 0 3 7 5 180

200

400

600

800

1000

1200

70% of CV were in 1-5 volt range

13% of CV were in 5.1-10 volt range

7% of CV were in 10.1-15 volt range

Full Line potential !

CV Events by Asset Owner

TPA = TTC, BIA, Traffic Lights, Bus SheltersOther = Customer owned assets

Post Level III

Contact Voltage Histogram

119

23 11 8 4 2 0 1 1 1 0 0 1 10

200

Post Level III 

Summary of Technical Assessment, Diagnosis, Challenges

Common Locations of CV

Metallic plates and coversDirect contact with exposed conductor or indirectly through another

medium (i.e. salt water)

Concrete/Steel Poles Direct contact with exposed conductor

Concrete Structures (including sidewalks, bridges, etc…)

Conductive salt water saturates concrete and forms a voltage gradient

Signalized IntersectionsIntegrity of the grounding grid is suspect or insufficient

Examples of Inspection Findings

•Split-bolt tape insulation has degraded

120 volts measured

Examples of Inspection Findings

•PVC tape on split-bolt splice improperly applied

Exposed conductor

Examples of Inspection Findings

•Handwell w/ live supply was paved over

Excavated handwell with live conductors

Examples of Inspection Findings

•Damage from civil contractor

Rebar from sidewalk has penetrated the handwell walls

Examples of Inspection Findings

•Damage from civil contractor

Concrete has penetrated handwell

Common Diagnosis

Aging AssetsInsulation degradation, accelerated by harsh environment, including water, ice, salt

Degradation of cable jackets, brittle/cracked, likely due to repeated hot/cold seasonal change

Third party damageHandwells paved over, damaged, rebar penetrating, unauthorized access

Non-compliance with construction standardsSubstandard /unsuitable materials i.e., marrettsPoor workmanship i.e., taped splicesFailure to replace insulation barriers, guards, etc…

Challenges

1. CV detected on 3rd party assetsTransit & traffic polesPrivate infrastructure (advertisements, street furniture, lighting)Other infrastructure (Other Utilities, control cabinets, conduit, etc…)

Need a process for communication/resolutionRegulatory compliance

Cost recovery/allocationAre Service Level Agreements (SLA’s) required?Legislatively, who is responsible?

2. 3rd party accessControl access (via process, design, etc…)Physical barriers (proprietary locking mechanism, special bolts, etc…)Engagement & communication of process, practices, public safety

Challenges . . . cont’d

3. Safety by designHow do you ensure the design is as safe as is reasonably possible?Are you using the correct equipment/materials for the job?Circuit Protection - need to revisit legacy standards?

4. Installation practicesHow do you ensure installations are as per standard?How do you efficiently execute QA/QC?What are acceptable tolerances, margin for error?

5. Data & RecordsDo you know where all your infrastructure is located?Data collection/storage costs $$$. GIS vs. paper vs. electronic?Harmonization of records (Legacy systems, standards, records)

Moving Forward

Our Asset Management Plan

Asset Investment Plan

Level III Emergency Follow Up

Plans to complete follow up actions from Level III emergency contact voltage inspection are in place

Where permanent fixes were not possible during the Level III emergency, our 2010 EDR filing proposes to:

Replace handwell lids with non conductive lidsPrevent unauthorized accessRepair deteriorated wiring in handwells/hand-holesReplace poles that are no longer feasible to repairRevisit “no access possible” locations to verify presence of

unauthorized access/contact voltage

Asset Transition, Maintenance,Data Collection

Acquire street light assets via regulatory processIntegrate SL assets into LDC GIS registryConduct asset condition assessmentInclude asset investment plan into next OEB rate application

Develop appropriate maintenance programsVisual inspectionManual detection (readily available technologies, inexpensive, efficient?) Mobile scanning- Proprietary technology – limited vendors, efficient, effective, comprehensive, fast- Considerably more expensive relative to manual testing, needs regulatory approval

Data collectionUtilize hand-held PDA’s (robust data, pictures, GPS location, etc…)Reduce response time to serious hazards

Hazard Mitigation Strategies

Leverage existing THESL asset condition tools (i.e. Asset Condition Assessment / Health Index Calculator) to prioritize work from highest potential hazard to lowest. Possible recommendations may include:

Replacement of entire handwell with composite materialSpec higher quality electrical wireIncrease electrical insulation of the pole structureExplore new connector technologiesImprove electric circuit protection (i.e., fusing, isolation transformers)

Other technologies i.e. non-conductive lids, insulating paint

Specifically…

•THESL has included in our 2010 EDR filing:

Replacing 1,000 “high risk”handwells with non-conductive ones

Replacement of 8,000 handwell covers with non-conductive covers

Grounding 2,000 handwell frames where replacement is not possible

Summary

• Complete remedial work in 2009 arising from the Level III emergency

• Implement permanent CV Scanning & support processes and systems

• Work with OEB on cost recovery (Level III emergency) & go-forward costing

• Seek regulatory approval to acquire street lighting assets

• Develop short-term 2009/10 street light investment plan

• Develop long-term investment plan (standards, capital, O&M)

• Continue to work collaboratively with agencies, boards, commissions, and private sector to resolve issues (i.e. Electrical Safety Association, City Traffic, Business Improvement Associations, Contractors, other Utilities, etc…

• Enhance community outreach (education, media, etc…)

In Closing . . .

We at Toronto Hydro are dedicated to ensuring our assets do not pose safety risks to the public or employee

We are working together with regulators and safety authority to mitigate any outstanding issues arising from Level III emergency

We are prudently increasing our investment and actively improving our own standards and processes to mitigate sources of contact voltage