d1 t09 s01 standardization v09 - toronto hydro · pdf filethe standardization portfolio...

Toronto Hydro-Electric System Limited EB-2009-0139
Exhibit D1 Tab 9
Schedule 1 ORIGINAL Page 1 of 15
EMERGING REQUIREMENTS 1 2
EQUIPMENT STANDARDIZATION 3
THESL plans, designs and constructs distribution system assets in accordance with 4
approved standards. The standards are developed by THESL to achieve the objectives of 5
public and employee safety in compliance with the requirements of the Electrical Safety 6
Authority (ESA). There are some assets in service that were installed prior to the 7
development and adoption of the standards currently in use. These legacy installations 8
are left over from the amalgamation of the former utilities of Toronto Hydro, Etobicoke 9
Hydro, North York Hydro, Scarborough PUC, East York Hydro and York Hydro into the 10
current single utility. 11
12
THESL upgrades non-compliant assets as part of its standard design rebuild to bring 13
them into compliance with current standards and modernize the distribution system. 14
Assets requiring upgrade to the current standards are selected and prioritized by taking 15
into consideration the levels of risk they pose to public and employee safety and power 16
system reliability. The standardization portfolio includes funds for upgrading or 17
replacing non-compliant distribution system components and legacy assets that were 18
installed prior to amalgamation and are identified as obsolete. The major standardization 19
initiatives for 2010 are outlined in Table 1. 20
21

Exhibit D1 Tab 9
Table 1: Equipment Standardization Portfolio Fund Allocation Breakdown 1
($millions) 2
Portfolio Project Description(s) Total Investment
Handwell
Standardization Contact voltage remediation program 9.2
Switch and
Feeder Lateral
Standardization
PMH high voltage switchgear installations 4.6
SCADAMATE remote control switch installations 8.6
Overhead fuse installations 3.2
Cable
Standardization Upgrading of streetlighting cable 5.2
TX
Standardization Replacement of non-standard transformers 1.9
32.7
3
HANDWELL STANDARDIZATION 4
The handwell standardization portfolio involves work resulting from the level III 5
emergency response that THESL declared in February of 2009. This emergency 6
response was initiated after two separate incidents of dogs being fatally shocked in the 7
vicinity of energized metallic handwell covers. These incidents occurred between 8
November 2008 and January 2009. Over a one month period, all handwells in the City 9
were inspected and made safe to protect the public from contact voltage hazards. The 10
inspection revealed an additional 104 metallic handwell covers that had become 11
energized from 1 to 120 volts. Funds allocated to this portfolio are required to upgrade 12
all the THESL-owned handwells currently installed. The upgrades are necessary to 13
reduce the possibility of inadvertent energization and therefore reduce the risk to public 14
safety. 15

Exhibit D1 Tab 9
1 Figure 1: An open handwell photographed during the Level III inspections. Harsh 2
conditions increase the risk of insulation failure on the cable which can lead to 3
energization of the metallic frame. 4
5 Figure 2: A handwell in the process of being made safe during the Level III 6
emergency. New connectors have been installed on two splices. 7

Exhibit D1 Tab 9
1 Figure 3: Current handwell standard. The frame and cover are made of cast iron. 2
In the field there are 8, 11, 12 and 18 diameter legacy installations. 3
4
This investment will be used to develop and execute a program to bridge the gap between 5
the immediate make safe repairs completed during 2009 to when all locations are fully 6
repaired. This will be accomplished by either excavating the entire assembly from the 7
sidewalk and installing a new standard non-conductive polymer concrete handwell, or by 8
removing the existing metallic cover and replacing it with a non-conductive cover. The 9
cover incorporates a shroud which extends into the handwell and prevents an exposed 10
conductor from contacting the metallic frame. The $9.2 million dollar estimate is based 11
on the costs to address all 11000 handwells accordingly: 12
1) Excavate and completely replace 1000 handwells deemed to be high risk, 13
2) Replace 8000 handwell covers only with non-conductive covers, and 14
3) Ground 2000 handwell frames, which is seen as a last resort for locations where 15
neither cover replacements nor excavation, is feasible. 16
17

Exhibit D1 Tab 9
This breakdown includes the assumption that excavation and installation of new units 1
will be more time consuming and will present more installation difficulties than cover 2
replacements only (which do not require any cutting or rebuilding of sidewalks). The go 3
forward estimate of future programs will be adjusted as THESL receives feedback and 4
gains experience working with the new designs. THESLs plan is to effectively mitigate 5
the potential for contact voltage on all its handwells in 2010. 6
7
SWITCH AND FEEDER LATERAL STANDARDIZATION 8
This portfolio involves the standardization of the distribution system in the former district 9
of Etobicoke through the installation of pad-mounted switchgear, overhead fuses and 10
remote operated SCADAMATE switches. In many cases minor failures cause large scale 11
outages in both frequency and duration for customers due to the inflexibility of the 12
system, as illustrated in Table 2 below. 13
14
Table 2: Examples of Outages in Targeted Area 15
Year Description Cause Customers
Interrupted
Duration
(minutes)
2009 Richview TS, 88M45 feeder was
interrupted due to an underground primary
cable fault
Defective
Equipment
6,700 40
2009 Richview TS was interrupted due to loss
of supply from Hydro One
Loss of
Supply
4,632 45
2009 Horner TS, R30M4 feeder was interrupted
due extreme wind. Crews found a tree
branch on the 3-phase primary
Adverse
Weather
4,192 445
2009 Richview TS, 88M17 feeder was
interrupted due to a customer owned
equipment which failed due to the
electrical room flooding
Foreign
Interference
3,690 29

Exhibit D1 Tab 9
From Figure 4 below, the total number of customers interrupted per year in the Etobicoke
district is showing an upward trend.
1 Figure 4: Total number of customer interruptions per year since 2004. 2
3
In the ten years since amalgamation THESLs construction standards have been 4
harmonized and updated and it is becoming more difficult to support legacy installations. 5
While this area will eventually be addressed under THESLs sustaining capital programs, 6
current trends in reliability metrics (as seen above) indicate that work will be required in 7
the short term. This investment will be used to bring the feeders to standard by installing 8
overhead fuses, pad-mounted switchgear and remote controlled SCADAMATE switches 9
in the 27.6 kV and 13.8 kV distribution systems in this area. This equipment will allow 10
system sectionalization, thereby reducing the scale and scope of customers affected 11
during system outages. Tie-points will be provided between feeders which will further 12
reduce the length and frequency of outages. SCADAMATE switches will also facilitate 13

Exhibit D1 Tab 9
future feeder automation and support THESLs smart grid plans. 1
2
Table 3: Planned Installations for Distribution System Standardization 3
Actions 13.8 kV 27.6 kV
Number of overhead fuses to be installed 17 540
Number of PMH switchgear (with Fault
Indicators) to be installed 28 20
Number of SCADAMATE switches to be
installed 47 60
4
CABLE STANDARDIZATION 5
Inspections performed during the 2009 contact voltage emergency indicate that 6
streetlighting cable insulation is breaking down and is in poor condition, increasing the 7
risk of contact voltage re-occurrence. Crews observed brittle and cracked cable jackets 8
and reported instances where voltages were measured on the exterior of the jackets. In 9
total, three hundred ninety-nine work orders for replacement of cable in handwells were 10
created as a direct result of these inspections. It was also observed that water, ice and 11
road salt are accumulating in handwells, which is contributing to the degradation of the 12
cable insulation in addition to normal degradation due to aging. This investment, 13
estimat

d1 t09 s01 standardization v09 - toronto hydro · pdf filethe standardization portfolio...

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