INCREMENTAL CAPITAL ELIGIBLE PROJECTS DETAILS Capital Expenditure $3,931,290 ($3,530,841 in 2013) Background:

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1 EB IRM Application Filed: September, 0 Page of INCREMENTAL CAPITAL ELIGIBLE PROJECTS DETAILS Program Title: Switching Units and Transformers Capital Expenditure $,,0 ($,0, in 0) Background: PowerStream owns over,000 underground switching units and transformers. Underground switching units (padmount switchgear and Mini-rupter switches) and transformers (padmount, vault and submersible) are critical components of PowerStream s Electrical Distribution System ( EDS ). As these units age and their functional abilities deteriorate, the need for replacement increases in order to maintain the integrity and safety of the EDS. Switchgear Padmounted switchgear units are used in distribution cable feeder loops supplying residential subdivisions and commercial/industrial customers. Switchgear units are utilized to isolate/control other equipment, and to reconfigure the distribution cable feeder loops for maintenance, restoration or other operating requirements. Each year, PowerStream inspects padmount switchgear according to the inspection requirements established by the OEB Distribution System Code and ESA Regulation /0. candidates are selected based on a combination of inspection results ( physical condition) and a calculated asset health index. The following factors are used to calculate the switchgear asset health index: Equipment age Structural integrity Presence of hotspots Condition of mechanical mechanism Condition of bus insulation Switchgear units that have been classified to have a poor health index condition are proposed to be replaced in 0. 0 Electricity Distribution Rates Application

2 EB IRM Application Filed: September, 0 Page of 0 0 Mini-rupter Switches Mini-rupter switches are used in distribution feeder loops supplying industrial commercial/industrial customers. Mini-rupter units are three pole-gang operated interrupter switches that are used for switching on underground distribution circuits and are typically installed in vault rooms (i.e. a confined space). There have been several flashover failures of Mini-rupter switches and the risk of confined space injury to personnel has reached a point where restrictions on switching of these units (not to be switched energized) have been put in place. Similar to switchgear, PowerStream inspects Mini-rupter installations according to the inspection requirements established by the OEB Distribution System Code and ESA Regulation /0. candidates are selected based on a combination of inspection results ( physical condition), confined space safety risk assessment to personnel and a calculated asset health index. The following factors are used to calculate the Mini-rupter asset health index: Equipment age Structural integrity Presence of hotspots Physical condition of arc interrupter. Condition of quick-make and quick-break mechanism Mini-rupter units that have been classified to have a poor health index condition are proposed to be replaced in 0. Submersible Transformers Transformers are used to step down the primary voltage to a lower secondary voltage that supplies customers. A number of submersible transformers are installed at the bottom of street light poles. These are old and unique installations that include a submersible transformer in a small congested ground access pit, open air fusing in a metalclad streetlight fixture and fixed primary connections. They are obsolete, no longer manufactured and spare parts are nonexistent. The fixed primary connection does not allow for switching resulting in considerable 0 Electricity Distribution Rates Application

3 EB IRM Application Filed: September, 0 Page of 0 0 outage disruptions to customers whenever work is required to be performed on the units or in the general vicinity. Submersible transformers have been classified to have a poor condition health index and are proposed to be replaced in 0. Padmount Transformers Padmount transformers may be single-phase or three-phase depending on the customer and type of load. The pad mount transformers in PowerStream s distribution system consist of transformer as low as 0kVA typically supplying residential customers and as high as,000 kva supplying industrial customers. These transformers are oil filled and employ sealed tank construction. Distribution transformers feeding residential customers, typically have minimal reliability impact upon failure. As such, utilities (including PowerStream) generally operate residential distribution transformers to failure due to the small per unit residential impact. For severely degraded units, there can be safety and environmental consequences, which may necessitate replacement before failure. For larger distribution transformers supplying commercial or industrial customers, where reduction in reliability impacts may be high, transformers may be replaced as they near the end of life. Similar to switchgear, PowerStream inspects padmount transformer installations according to the inspection requirements established by the OEB Distribution System Code and ESA Regulation /0. candidates are selected based on safety or environmental concern identified through the inspection program. Visual inspections provide considerable information on transformer asset condition. Leaks, cracked bushings, and rusting of tanks can all be established by visual inspections. Inspected transformers will be classified in one of three categories: Code A = Corrective measures/follow-up are required at the earliest possible opportunity, i.e. immediate; Code B = Assessment required for corrective action in the next budget cycle; and Code C = No specific time frame for corrective measures are required. Follow the regular maintenance cycle. 0 Electricity Distribution Rates Application

4 EB IRM Application Filed: September, 0 Page of 0 0 Padmount transformers that have been classified as Code B are proposed to be replaced in 0. Program Description The Switching Unit and Transformer program therefore includes replacing end of life units for: Pad- Mounted Switchgear Mini-rupter Switches Pad- Mounted Transformers Submersible Transformers Switchgear Switchgears have shown an increasing failure trend over the past five years. Figure : Switchgear Failures 00-0 (,00 V) 0 Electricity Distribution Rates Application

5 EB IRM Application Filed: September, 0 Page of 0 0 Maintaining focus on proactive replacement will over time begin to reduce the rate of failures to a point where a balance is achieved between annual asset health degradation and annual replacement programs. PowerStream proposes that 0 switchgears be replaced in 0. The majority of the switchgear will be replaced with industry standard SF insulated switchgear units. SF switchgear units are sealed units and all internal live parts are encapsulated. The inherent design of SF switchgear enables these units to be relatively free from contamination and moisture issues, as compared to the switchgear they are replacing. SF switchgear are dead front units which means that the cables are connected to the switchgear through insulated connectors thus eliminating exposure of any live component to dirt and moisture. SF switchgear require minimal maintenance as all the compartments are sealed. Mini-rupter switches PowerStream proposes that Mini-rupter switches are to be replaced in 0. They will be replaced with industry standard solid dielectric switches. Solid dielectric switches utilize a submersible epoxy polymer insulation system to fully encapsulate the internal switch components. The inherent design of solid dielectric switches enables these units to be free from contamination and moisture issues, as compared to the open air insulated Mini-rupters they are replacing. Solid dielectric switches are dead front unit which means that the cables are connected to the switches through insulated connectors thus eliminating exposure of any live component to dirt and moisture. Solid dielectric switches require minimal maintenance. Submersible Transformers PowerStream proposes that obsolete submersible transformers are to be replaced in 0. They will be replaced with industry standard padmount transformers. Padmount transformers are oil filled dead front units with separable primary terminations. Padmount Transformers The intent of this project is to address the transformers which pose near term safety or environmental risk. PowerStream proposes that 0 padmount transformers, identified as Code B through the 0 inspection program, are to be replaced in 0. They will be replaced with industry standard padmount transformers. 0 Electricity Distribution Rates Application

6 EB IRM Application Filed: September, 0 Page of Details The total cost of the 0 Switching Unit and Transformer replacement program is estimated at $.M, and PowerStream forecasts that the replacements will be complete by the end of 0, such that the new assets will be in service during that year. See Table below for the category of assets and the quantities that will be replaced in 0 under the Switching Unit and Transformer program. Project Title Pad- Mounted Switchgear Mini-rupter Switches Submersible Transformer Pad-Mount Transformer Risk Assessment Table : Total of 0 Switching Unit and Transformer Units Design Labour Contract Material Total 0 $, $,0 $ 0,0 $,, $,, $,0 $, $ 0 $,0 $, $, $, $ 0, $, $, 0 $, $,0 $ 0,0 $,00 $, $,,0 As equipment gets older and the health condition deteriorates, it will eventually fail. This has a direct impact the utility goal to deliver power to customers in a safe and reliable manner. This degrades customer service metrics. The risk of not addressing equipment at end-of-life status can also have consequences that can impact operating efficiency and the environment. Lack of a proactive replacement program will result in equipment being replaced only under emergency response situations with associated increases in annual capital and operating costs. 0 Electricity Distribution Rates Application

7 EB IRM Application Filed: September, 0 Page of Switchgear failure can be catastrophic (i.e. oil fire) in certain conditions and can pose a safety risk to workers and the public and have a negative impact on the local environment (oil spill). Failures will also negatively impact system reliability. Mini-rupter failures, especially those in a confined space, pose a safety risk to workers. Failures will also negatively impact system reliability. Submersible transformers are obsolete and as per existing configuration, pose a safety risk to workers and negatively impact system reliability. Padmount transformer failure, similar to switchgear, can be catastrophic in certain conditions and can pose a safety risk to workers and the public and have a negative impact on the local environment. Failures will also negatively impact system reliability. Reliability Benefit PowerStream staff has calculated that proactively addressing the pieces of equipment in the 0 Underground Equipment program will save: approximately failures; 0,000 Customer Minutes of Interruption ( CMI ) due to switchgear 0 approximately 00 CMI due to Mini-rupter failure; approximately,000 CMI due to submersible transformer failures; approximately,00 CMI due to padmount transformer failures; versus a do nothing approach. The CMI saved is expected to provide an equivalent customer monetary value (outage avoidance) in the order of $.M to the combined residential and commercial/industrial customer sectors. 0 Electricity Distribution Rates Application