EB-00-0 Exhibit D Schedule Page of EMERGING REQUIREMENTS 0 EQUIPMENT STANDARDIZATION THESL plans, designs and constructs distribution system assets in accordance with approved standards. The standards are developed by THESL to achieve the objectives of public and employee safety in compliance with the requirements of the Electrical Safety Authority ( ESA ). There are some assets in service that were installed prior to the development and adoption of the standards currently in use. These legacy installations are left over from the amalgamation of the former utilities of Toronto Hydro, Etobicoke Hydro, North York Hydro, Scarborough PUC, East York Hydro and York Hydro into the current single utility. 0 THESL upgrades non-compliant assets as part of its standard design rebuild to bring them into compliance with current standards and modernize the distribution system. Assets requiring upgrade to the current standards are selected and prioritized by taking into consideration the levels of risk they pose to public and employee safety and power system reliability. The standardization portfolio includes funds for upgrading or replacing non-compliant distribution system components and legacy assets that were installed prior to amalgamation and are identified as obsolete. The major standardization initiatives for 00 are outlined in Table.
EB-00-0 Exhibit D Schedule Page of Table : Equipment Standardization Portfolio Fund Allocation Breakdown ($millions) Portfolio Project Description(s) Total Investment Handwell Standardization Contact voltage remediation program. Switch and Feeder Lateral Standardization Cable Standardization TX Standardization PMH high voltage switchgear installations. SCADAMATE remote control switch installations. Overhead fuse installations. Upgrading of streetlighting cable. Replacement of non-standard transformers.. 0 HANDWELL STANDARDIZATION The handwell standardization portfolio involves work resulting from the level III emergency response that THESL declared in February of 00. This emergency response was initiated after two separate incidents of dogs being fatally shocked in the vicinity of energized metallic handwell covers. These incidents occurred between November 00 and January 00. Over a one month period, all handwells in the City were inspected and made safe to protect the public from contact voltage hazards. The inspection revealed an additional 0 metallic handwell covers that had become energized from to 0 volts. Funds allocated to this portfolio are required to upgrade all the THESL-owned handwells currently installed. The upgrades are necessary to reduce the possibility of inadvertent energization and therefore reduce the risk to public safety.
EB-00-0 Exhibit D Schedule Page of Figure : An open handwell photographed during the Level III inspections. Harsh conditions increase the risk of insulation failure on the cable which can lead to energization of the metallic frame. Figure : A handwell in the process of being made safe during the Level III emergency. New connectors have been installed on two splices.
EB-00-0 Exhibit D Schedule Page of 0 Figure : Current handwell standard. The frame and cover are made of cast iron. In the field there are,, and diameter legacy installations. This investment will be used to develop and execute a program to bridge the gap between the immediate make safe repairs completed during 00 to when all locations are fully repaired. This will be accomplished by either excavating the entire assembly from the sidewalk and installing a new standard non-conductive polymer concrete handwell, or by removing the existing metallic cover and replacing it with a non-conductive cover. The cover incorporates a shroud which extends into the handwell and prevents an exposed conductor from contacting the metallic frame. The $. million dollar estimate is based on the costs to address all 000 handwells accordingly: ) Excavate and completely replace 000 handwells deemed to be high risk, ) Replace 000 handwell covers only with non-conductive covers, and ) Ground 000 handwell frames, which is seen as a last resort for locations where neither cover replacements nor excavation, is feasible.
EB-00-0 Exhibit D Schedule Page of This breakdown includes the assumption that excavation and installation of new units will be more time consuming and will present more installation difficulties than cover replacements only (which do not require any cutting or rebuilding of sidewalks). The go forward estimate of future programs will be adjusted as THESL receives feedback and gains experience working with the new designs. THESL s plan is to effectively mitigate the potential for contact voltage on all its handwells in 00. 0 SWITCH AND FEEDER LATERAL STANDARDIZATION This portfolio involves the standardization of the distribution system in the former district of Etobicoke through the installation of pad-mounted switchgear, overhead fuses and remote operated SCADAMATE switches. In many cases minor failures cause large scale outages in both frequency and duration for customers due to the inflexibility of the system, as illustrated in Table below. Table : Examples of Outages in Targeted Area Year Description Cause 00 Richview TS, M feeder was Defective interrupted due to an underground primary Equipment cable fault 00 Richview TS was interrupted due to loss Loss of of supply from Hydro One Supply 00 Horner TS, R0M feeder was interrupted Adverse due extreme wind. Crews found a tree Weather branch on the -phase primary 00 Richview TS, M feeder was Foreign interrupted due to a customer owned Interference equipment which failed due to the electrical room flooding Customers Interrupted Duration (minutes),00 0,,,0
EB-00-0 Exhibit D Schedule Page of From Figure below, the total number of customers interrupted per year in the Etobicoke district is showing an upward trend. Figure : Total number of customer interruptions per year since 00. 0 In the ten years since amalgamation THESL s construction standards have been harmonized and updated and it is becoming more difficult to support legacy installations. While this area will eventually be addressed under THESL s sustaining capital programs, current trends in reliability metrics (as seen above) indicate that work will be required in the short term. This investment will be used to bring the feeders to standard by installing overhead fuses, pad-mounted switchgear and remote controlled SCADAMATE switches in the. kv and. kv distribution systems in this area. This equipment will allow system sectionalization, thereby reducing the scale and scope of customers affected during system outages. Tie-points will be provided between feeders which will further reduce the length and frequency of outages. SCADAMATE switches will also facilitate
EB-00-0 Exhibit D Schedule Page of future feeder automation and support THESL s smart grid plans. Table : Planned Installations for Distribution System Standardization Actions. kv. kv Number of overhead fuses to be installed 0 Number of PMH switchgear (with Fault Indicators) to be installed Number of SCADAMATE switches to be installed 0 0 0 CABLE STANDARDIZATION Inspections performed during the 00 contact voltage emergency indicate that streetlighting cable insulation is breaking down and is in poor condition, increasing the risk of contact voltage re-occurrence. Crews observed brittle and cracked cable jackets and reported instances where voltages were measured on the exterior of the jackets. In total, three hundred ninety-nine work orders for replacement of cable in handwells were created as a direct result of these inspections. It was also observed that water, ice and road salt are accumulating in handwells, which is contributing to the degradation of the cable insulation in addition to normal degradation due to aging. This investment, estimated at $. million dollars, will be used to initiate a proactive program to identify and replace end of life streetlighting cable. Initially 0 kilometres of cable are planned to be replaced which represents the poorest condition cable assets and approximately percent of the streetlighting cable in Toronto. The program will initially focus on downtown Toronto, where the infrastructure is oldest and in poorest condition and has a high volume of pedestrian traffic which represents the highest risk.
EB-00-0 Exhibit D Schedule Page of TRANSFORMER STANDARDIZATION Funds listed under transformer standardization are allocated to initiate a program to proactively identify and replace numerous non-standard transformers which currently exist in the distribution system. Many of these legacy installations were installed by former utilities prior to amalgamation as evaluation trials or pilot projects. The following items outline three types of legacy installation that will be targeted and the justification for replacing them. Further details are found in project justification for Exhibit D, Tab, Schedule -. 0 Transformer Type: ABB Solid Insulated Dielectric Transformers Area(s) Installed: Scarborough, North York, old Toronto Number of In-service Units: Reason for Proactive Replacement: These solid insulated dielectric transformers were originally designed by Asea Brown Boveri (ABB) and installed as part of a pilot project. Of the seven units installed since 00, two have failed. The cause of the failures is due to manufacturing defects and/or the ingress of moisture into the insulation, a problem experienced by other Canadian utilities who have also installed the same transformers. 0 Figure : Failed ABB solid dielectric insulation transformer.
EB-00-0 Exhibit D Schedule Page of These two failures occurred out of warranty and resulted in prolonged outages due to the non-standard aspect of the original installation. Because the manufacturer does not support this product and no spare units are available, additional failures will require a prolonged retrofit and outage. A proactive replacement program to retrofit and upgrade the vault to THESL s standard submersible transformer will avoid such an outage. Figure : Drawing of a standard submersible transformer in an underground vault (from THESL Construction Standard -00). 0 Transformer Type: Single phase. kv and. kv submersible transformers Area(s) Installed: Scarborough, North York Number of In-service Units:,000 Reason for Proactive Replacement: These legacy installations do not incorporate load break switches as specified in the current standard. As a result, when there is a fault, which is a common occurrence with the direct buried cables in the area, the entire chain of submersible transformers and the customers supplied by those transformers must be Number of in-service units is approximate
EB-00-0 Exhibit D Schedule Page 0 of de-energized, or the crew must remove the energized transformer elbows so that repairs can proceed. Standard transformers with load break switches will be placed at normally open points on the chain to reduce the number of customers affected by an outage and improve safety by eliminating the need for crews to work on energized elbows. See Figure and Table for an example of the reliability improvements to the system. Figure : Failed legacy submersible transformer, without line isolation switches. 0 Figure : THESL s current standard submersible transformer with isolation. Switches S and S allow for isolation without de-energizing downstream.
EB-00-0 Exhibit D Schedule Page of Figure : Example of system improvements resulting from transformer standardization. This figure shows the reliability improvement from replacing one transformer in a chain of legacy installations with THESL s standard unit.
EB-00-0 Exhibit D Schedule Page of Table : Summary of Reliability Improvements (from example in Figure ) Measure Legacy Installations Standard Installations Improvement from Standardization Customer Minutes Out Customers Interrupted,000,00 0 % 0 0 % 0 Transformer Type: Single phase, low-height submersible transformers Area(s) Installed: Etobicoke Number of In-service Units: 00 Reason for Proactive Replacement: A number of non-standard low height submersible transformers are installed in the Etobicoke area. These -inch high units are housed in non-standard steel vault enclosures. Many of the existing legacy installations do not incorporate line isolation switches and due to their non-standard size they cannot be directly substituted with a standard submersible transformer without a prolonged outage to retrofit the vault. THESL s approach is to eliminate this non-standard situation and replace the low-height submersible transformer with THESL s current standard installation. This will provide the reliability and safety benefits outlined in the previous section on transformers without line isolation switches (see Table ), and eliminate the need to purchase and stock small quantities of these unique units.
EB-00-0 Exhibit D Schedule Page of Figure 0: Low-height submersible transformer. 0 Transformer Type: Singe phase, pole mounted, completely self-protected ( CSP ) transformers Area(s) Installed: North York, York Number of In-service Units:,00 Reason for Proactive Replacement: These legacy transformers contain built-in circuit protection / fuses. The fuse on standard installations is located outside of the transformer tank, as can be seen in Figure.
EB-00-0 Exhibit D Schedule Page of Figure : Standard pole-mounted transformer installation with external fuse Figure : A recovered CSP transformer
EB-00-0 Exhibit D Schedule Page of With THESL s current standard, the external fuse can be replaced without replacing the transformer. When a fuse blows, standard practice is to replace the fuse once, which generally takes fifteen minutes. If it blows again (which occurs roughly 0 percent of the time) it is assumed that there is a problem with the transformer and it will then be replaced. With a CSP transformer, the crew does not have the option of replacing the fuse because it is contained in the tank. Instead, the entire transformer must be replaced. This generally takes one and a half hours. As a result, THESL s current standard installation offers operational advantages which improve the average reliability of the system. This is summarized in Table. 0 Table : Reliability of Standard Installation vs. CSP Installation CSP Installation Standard Installation Minutes Out Due To 0 minutes (replace minutes (replace Blown Fuse transformer) = 0 fuse) x 0% + (Typical) minutes (replace fuse and replace transformer) x 0% = 0 Improvement from Standardization % This investment will be used to initiate a program to replace CSP transformers where they are installed on poles of sufficient size to accommodate a standard transformer.