Topic:"Unplanned Outage" in M12619

REDACTED REDACTED (CONFIDENTIAL INFORMATION REMOVED) 2026 ACE Plan CONFIDENTIAL (Attachments Only) 1 Distribution Upgrades and Replacements 2 3 Figure 44: Distribution Upgrades and Replacements 2026 ACE Plan Forecast D005 Unplanned Replace...

AI summary The 2026 ACE Plan outlines forecasts for distribution upgrades and replacements, including unplanned equipment replacement, regulatory replacements, and provincial storm-related expenditures. These forecasts are based on historical spending averages, adjusted for inflation, and may vary depending on annual decisions and storm activity.

1 2 The forecast for D005 for 2026 was developed based on the previous 5-year average for spend 3 from 2021-2025 plus an annual inflation of 1.80 percent. This forecast resulted in an estimated 4 8,446 person days of work at a unit cost of...

AI summary The forecast for D005 in 2026 is based on the previous 5-year average of spend from 2021-2025, factoring in 1.80% annual inflation. The forecast includes overtime labour costs due to unplanned asset failures occurring at any time, including outside normal business hours. Historical data on equipment failures is referenced, with more details to be provided in future ATO filings.

Major Extreme 2 3 4 Figure 75 below provides detail on outage causes for the three event days experienced so far in 5 2025. 6 7 Figure 75: Detail on Outage Causes for identified Event Days Significant Major Extreme CEA Hours of Hours of Ho...

AI summary The document provides an analysis of outage causes for three event days in 2025, highlighting that the majority of outages were due to loss of supply and tree contacts, with scheduled outages and unknown causes contributing smaller proportions.

9 Foreign Interference 10,087 0 0 4.03% Total 250,026 0 0 1 2 Over 20 percent of all identified event day outage hours in 2025 have been caused by tree contacts. 3 Furthermore, a significant portion of events coded as adverse weather are l...

AI summary The text highlights that over 20% of event day outage hours in 2025 were caused by tree contacts, emphasizing the need for continued investment in vegetation management and right-of-way widening. Several capital projects are identified to address these issues in 2026.

2026 ACE Plan C0080206 Page 2 of 5 JUSTIFICATION: Justification Criteria: Thermal Sub Criteria: Equipment Replacement/ Refurbishment Why do this project? NS Power conducts condition and risk assessment and analysis based on the annual boil...

AI summary NS Power is proposing the replacement of boiler components such as tubes, tube shielding, and tube locks to enhance system reliability, mitigate the risk of unplanned outages, and ensure safe and cost-effective operation. The project is necessary due to the increased risk of failures from degraded components and the potential for higher costs from emergency repairs.

ment 2026 Start Date: 2026/08 In-Service Date: 2026/10 Final Cost Date: 2027/04 Function: Steam Forecast Amount: $1,024,385 DESCRIPTION: This project will replace refractory components in the Point Aconi boiler system, following inspection...

AI summary This project involves replacing refractory components in the Point Aconi boiler system to ensure safe and efficient operation, reduce thermal losses, and prevent unplanned outages. The work includes key areas such as cyclones, combustor-to-cyclone crossover ducts, and lower combustor sections, with a forecasted cost of $1,024,385.

onfirm this was done in its applications to the Board. In accordance with the Board’s directive, NS Power provided notice of this investment to participants in the DDA proceeding on December 3, 2025. Summary of Related CIs +/- 2 years: Pur...

AI summary NS Power is replacing refractory components in the Steam Production Plant at Point Aconi to ensure boiler reliability and prevent unplanned outages. The project is justified under the Thermal Equipment Replacement/Refurbishment criteria and aligns with the Board’s directive to notify participants in the DDA proceeding.

black start capability, 10-minute reserve, Volt-Ampere Reactive support and additional firm energy capacity to the NS Power electrical system. The unit was originally commissioned by NS Power in 1976 Summary of Related CIs +/- 2 years: Pur...

AI summary The document discusses the refurbishment of a gas turbine at Burnside to maintain essential ancillary services, citing wear and damage identified in a 2025 borescope inspection. The project is justified based on thermal criteria and equipment replacement needs to prevent unplanned outages and ensure system reliability.

ting investment. These units offer valuable operational flexibility and enhance system security through black start capability, rapid response, and improved system stability. Why do this project now? Completing the refurbishment of this en...

AI summary This text discusses the need to refurbish an engine in 2026 to prevent unplanned failures. Inspection in 2025 revealed damage to blades in the low-pressure and high-pressure compressor stages, indicating hidden wear that can only be confirmed through depot-level disassembly. The project is necessary due to the risk of failure and the need for compliance with OEM procedures.

f Retirement: Accounting Policy 6420 – Retirement and disposal of Capital Assets • Percentage of Asset Pool: 0.23% JUSTIFICATION: Justification Criteria: Transmission Plant Why do this project? The installation of the new switches will ena...

AI summary The project involves replacing two end-of-life switches (22N-603 and 22N-604) to enable live-line operation, reducing outages and improving reliability. The current switches are difficult to operate and their failure could lead to unplanned outages. A new ground grid and switches will allow more efficient operations and mitigate risks.

ng Station to the transmission grid, enabling the delivery of renewable hydroelectric energy. Its continued degradation poses operational, financial, and environmental risks. Why do this project now? The 96H-T1 transformer is consistently...

AI summary The document discusses the need to replace a transformer due to oil leaks and its location near a river, which poses environmental risks. Replacement is deemed necessary due to the transformer's degraded condition, lack of OEM support, and the cost-effectiveness of replacement over refurbishment.

timated August 2026); therefore, the Final Cost Date (June 2029) is six months after the last circuit breaker is expected to be replaced on this project (December 2028). Why do this project this way? Proactively replacing Pennsylvania circ...

AI summary NS Power is proactively replacing Pennsylvania circuit breakers on the transmission system due to the unavailability of replacement parts and manufacturer support. The project is being staged to reduce risk and ensure achievable annual scopes without excessive outages. A 10% contingency has been allocated for potential overtime and cost increases.

Retirement and Disposal of Capital Assets • Percentage of Asset Pool: 0.01% JUSTIFICATION: Justification Criteria: Distribution System Sub Criteria: Deteriorated Conductor Why do this project? This project is designed to mitigate the circu...

AI summary This project aims to replace a severely deteriorated conductor and associated overhead components on a distribution line to mitigate circuit risk, improve reliability, and prevent unplanned outages. The conductor has reached the end of its service life and poses increased operational risks.

d past outage performance has confirmed that conductor replacement is necessary. Delaying this project increases the likelihood of additional unplanned interruptions for customers served by this line. This project is deemed in service when...

AI summary The document discusses a conductor replacement project necessary to prevent additional unplanned outages. The project is phased, with the first distribution transformer replacement expected in August 2026 and the final cost date set for July 2027. The approach focuses on replacing the most deteriorated sections of the line. A 10% contingency has been applied to cover potential risks such as additional equipment replacement and tree trimming.

oles and Fixtures Distribution Plant – Overhead Conductors and Devices Distribution Plant – Line Transformers Estimated Life of the Asset: 45 years Retirement Information: • Categorization of Retirement: Accounting Policy 6420 - Retirement...

AI summary The document discusses a project to replace deteriorated poles and conductors on feeder 57C-426H to improve outage performance and enable future customer connections. The project is part of a broader effort to enhance the reliability of the distribution feeder, which has historically had poor performance due to an off-road section.

REDACTED (CONFIDENTIAL INFORMATION REMOVED) 2026 ACE Plan C0080612 Page 5 of 5 Legend: Inclusions: Date: December 12, 2025 Page 430 of 782 REDACTED REDACTED (CONFIDENTIAL INFORMATION REMOVED) 2026 ACE Plan C0080111 Page 1 of 5 CI Number: C...

AI summary This document outlines the 2026 RTU Deployment project, which involves installing 21 Remote Terminal Units (RTUs) in Nova Scotia substations to improve grid operation and emergency response times. The project is part of General Plant function and has a forecasted cost of $8,322,655.

2026 ACE Plan Appendix D Page 61 of 179 Nova ScoƟa Power Inc. Capital Planning & Capital Expenditure JusƟficaƟon Criteria Summary Document Forced Outage Rate Unplanned outages result in replacement genera on, o en at a higher cost than the...

AI summary Nova Scotia Power Inc. outlines capital expenditure justification criteria, emphasizing unplanned outages' cost impacts via probabilistic production models. System design adheres to NPCC and NERC standards, with NERC requirements enforced through NSEB regulatory approval. Transmission criteria combine protection performance and system dynamics, ensuring compliance with single contingency design principles.

1 2.0 RELIABILITY PERFORMANCE ANALYSIS 2 3 NS Power has developed the Plan to deliver a 20 percent improvement in the performance 4 standards overall average duration of outages (SAIDI) and to achieve the Performance Standards 5 SAIFI targ...

AI summary NS Power's Plan aims to improve system reliability by reducing outages caused by tree contacts and equipment failures, targeting a 20% improvement in SAIDI and achieving a SAIFI target of 2.05 by 2029. Grid modernization, including RTUs and remote connectivity, will mitigate outage impacts and enhance fault isolation.

NON-CONFIDENTIAL D005 - Unplanned Replace Deteriorated 2022 Actuals 2023 Actuals 2024 Actuals 2025 Actuals 2026 Budget Total Person Hours 66,136 76,808 82,403 61,742 67,571 Average Person Hour Cost ($) 270 315 320 348 332 Total Net Actuals...

AI summary The table presents actual and budget figures for 'Unplanned Replace Deteriorated' activities from 2022 to 2026, including total person hours, average person hour cost, and total net actuals in dollars. The data shows fluctuations in both hours and costs over the years.

1 1 Request IR-19: 18 explain why? 19 20 Response IR-21: 21 22 (a) NS Power allocates storm costs to both the D008 (Provincial Distribution Storm Routine) 23 and T001 (Unplanned Provincial Transmission Line Replacements) based on the 24 pr...

AI summary NS Power explains that storm costs are allocated between capital and operating expenses based on the nature of the restoration activities. Historical averages plus inflation are used to estimate storm costs, and reliability investments aim to improve overall system reliability and reduce outages, although the exact impact on storm-related outages is difficult to quantify.

2026 Annual Capital Expenditure (ACE) Plan (NSEB M12619) NSPI Responses to NSEB Information Requests 1 Request IR-30: 2 3 D005 - Unplanned Replacement Deteriorated Equipment 4 5 Board staff note that routine capital expenditures have been...

AI summary The document discusses NSPI's response to NSEB's information requests regarding the 2026 Annual Capital Expenditure (ACE) Plan, specifically focusing on unplanned replacement of deteriorated equipment, routine capital expenditures, and outage data for the past five years. NSPI attributes increased capital expenditures to higher-than-expected reactive power outages due to asset failures.

2026 ACE Plan NSEB IR-128 Attachment 1 Page 1 of 2 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Year Adverse Weather 1,417 4,522 727 617 Defective Equipment 1,881 1,899 1,973 1,714 Foreign Interference 1,080 871 995 991 Human Element 11 11...

AI summary The document provides a breakdown of outage causes and their impact on customer interruptions from 2022 to 2025, including percentages of total customer hours of interrupts, customer interruptions, and event counts attributed to factors such as adverse weather, defective equipment, tree contacts, and scheduled outages.

3 1 Request IR-19: 2 3 Please refer to Page 111 of 782, Figure 71: Customer Hours of Interruption and confirm to 4 what the percentage of hours refers (numerator and denominator). 5 6 Response IR-19: 7 8 The percentage of hours shown on Pa...

AI summary The document discusses a request (IR-19) regarding the interpretation of a percentage of hours in Figure 71, which represents customer hours of interruption (CHI) attributed to defective equipment. The response clarifies that the numerator is the CHI for a specific device type, and the denominator is the total CHI for all outage events coded as defective equipment in that year.

- Please refer to the Application Page 115 of 782, Lines 4-5, and Figure 75: Detail on Outage - Causes for Identified Event Days. (a) What are the 3 event days that are being referred to here. (b) Please provide the total number of event d...

AI summary The response clarifies that there was a typographical error in the application, indicating three event days when only two had occurred in 2025. The actual event days were February 17 and July 26, and the data and graphs remained accurate for these two days.

NON-CONFIDENTIAL 1 Request IR-21: 2 3 Please refer to the Application Page 115-116 of 782, Figure 75: Detail on Outage Causes for 4 identified Event Days. 5 6 (a) Please explain how the 11,601 hours of scheduled interruptions breaks down b...

AI summary The document discusses responses to requests regarding outage causes and definitions. It explains that 99% of scheduled interruptions during the February 17 winter storm were due to specific feeders in Middleton and Glace Bay. It also clarifies that approximately 40% of Loss of Supply outages are related to tree contacts on transmission lines.

NON-CONFIDENTIAL 1 Request IR-19: 2 3 With respect to project C0080266 (New Distribution ROW 11), please provide the number 4 of outage events, by year, for each feeder listed in attachment 1. Please provide the number 5 of both total outa...

AI summary The document requests data on outage events for specific feeders related to project C0080266, including total and tree contact outages by year. The response refers to NSEB IR-129 and provides a table with outage data from 2020 to 2025 for each feeder.

Q: Does NS Power appear to track person-hours for distribution routines? A: No, except for D005 – Unplanned Replace Deteriorated Equipment.[3](#page-5-2)

AI summary NS Power does not track person-hours for distribution routines, except for D005 – Unplanned Replace Deteriorated Equipment, as noted in the response.

Q: Is the lack of data on regular and overtime person-hours of concern? A: Yes. Several of the distribution routines have substantial overtime labour forecasts, and it is unclear whether NS Power has any internal practices for minimizing t...

AI summary The lack of data on regular and overtime person-hours is a concern, as several distribution routines have high overtime forecasts. NS Power uses an 'overtime-based model' due to the variability of outage calls, but tracking overtime use is essential to identify inefficiencies and opportunities for better scheduling.

2026 ACE Plan U-18 Attachment 1 Page 2 of 2 1 Undertaking U-19: % Total Customer Hours of Interrupts (CHI) Adverse Environment 0.6% 0.4% 0.2% 0.3% 0.1% 7.6% 0.5% 0.0% 1 ( / Adverse Weather 36.3% 57.3% 23.7% 23.6% 47.3% 29.8% 14.6% 10.6% De...

AI summary This table presents the distribution of customer interruptions and events across various causes for the 2026 ACE Plan. It includes percentages for factors such as adverse weather, defective equipment, tree contacts, and loss of supply, providing insights into the primary causes of service interruptions.

2.2.4 C0080111 – 2026 RTU Deployment [28] This project will install 21 new Remote Terminal Units (RTU) in substations throughout Nova Scotia over the next three to four years. The RTU and telecom will be installed at substations that curre...

AI summary This project involves the installation of 21 new Remote Terminal Units (RTU) in Nova Scotia substations over the next three to four years. The RTUs will improve system visibility and remote operability, enabling faster emergency response and outage resolution. The project aligns with NS Power's Advanced Grid Modernization program and its Five-Year Reliability Plan goals.

Request IR-52: - Page 106 discusses outage causes, please provide a table with the proportions of outages due - to tree contacts, the proportion due to failed equipment and the proportion due to other causes - for each of the last five yea...

AI summary The document requests a table detailing the proportions of outages caused by tree contacts, failed equipment, and other causes for each of the last five years.

Request IR-56: - Figure 75: Detail on Outage Causes for identified Event Days on pages 115 to 116. - a) Please update the table for the whole of 2025. - b) Page 116 explains that Loss of Supply events are related to tree contacts with tran...

AI summary Request IR-56 asks for an updated table detailing outage causes for the entire year of 2025 and additional information on transmission line outages caused by tree contacts, including their age, height, and geographic location, as well as details on non-tree contact outages.

Request IR-124: a) Please provide the number and duration of outages associated with routine switching activities or other work activities involving manual switches over the past 10 years. Please confirm the percentage of these outages tha...

AI summary Request IR-124 seeks information on outage statistics related to manual switching activities and confirmation of pricing obtained through competitive procurement. The request focuses on data from the past 10 years and the impact of live-line switch installation on reducing outages.

1 C0062043 IT Sharepoint Technical Migration Section 10.0 Routine Capital Program pages 59 to 86 In reference to Figure 34 – Routine Capital Spending Project Breakdown Yr/Yr on page 59 to 60. Please describe the reasons for the significant...

AI summary The document requests explanations for increased 2026 spending on transmission line replacements, distribution upgrades, and work vehicles. It notes that routine capital expenditures remain high despite being labeled as 'like for like' replacements, and questions whether NS Power has achieved efficiency gains. The increase is attributed to higher-than-expected reactive outages due to asset failures.

25 Request IR-10: 26 27 With respect to Section 11.1.4: 28 29 (a) Please provide tables with the data for Figures 59 and 60. Please provide columns for 30 Atlantic Utilities both with and without NS Power included, 31 32 (b) Please explain...

AI summary The request asks for data tables, explanations of reliability statistics calculations, 2024 reliability outcomes, developments influencing those outcomes, and the final terms of reference for CEATI's Grid Resiliency Working Group.

1 Request IR-25: 2 3 With respect to Appendix G, Figures 3 and 4: 4 5 (a) Please explain how and why the outage event count has been reduced by more than 50% 6 since 2022 for tree contacts and by nearly 50% for failure of equipment, but th...

AI summary The text requests an explanation for the reduction in outage event counts since 2022 and how the five-year reliability plan is expected to further reduce outages and customer hours of interruption.

CONTINUED DATE UND# DESCRIPTION REQUESTED OF FOR DUE DATE N-1 or the numbers in Exhibit N-6(i) response to NSEB IR-3 April 22, 2026 U-18 To review the IR response to the revised CA IR-19 (Exhibit N-8) and provide number of outage events by...

AI summary The document outlines several requests directed to Nova Scotia Power Inc. (NSPI) by the Nova Scotia Energy Board (NSEB) related to outage events, cost per kilometre for vegetation management work, and customer interruptions. These requests aim to gather detailed data for review and analysis.

- are a main cause of outages, both as standalone events and under the cause code of 'adverse - weather', and that vegetation management is the best way to address this issue. - 3 In the hearing, Charlene MacMullin (Ms. MacMullin), on beha...

AI summary The document discusses the relationship between vegetation management and power outages, with NS Power clarifying how its data on tree contacts and outages is interpreted. The SBA argues that NS Power's system should be resilient to storms less severe than Major Event Days (MEDs).

2.2.4 C0080111 – 2026 RTU Deployment [28] This project will install 21 new Remote Terminal Units (RTU) in substations throughout Nova Scotia over the next three to four years. The RTU and telecom will be installed at substations that curre...

AI summary This section discusses the 2026 RTU Deployment project by NS Power, which involves installing 21 new Remote Terminal Units (RTU) in Nova Scotia substations to improve grid visibility and emergency response times. The project supports the Advanced Grid Modernization program and aims to enhance grid resilience and reliability by enabling faster fault detection and outage resolution.

NS POWER PANEL 99 Cr-ex, (Murphy) outages that were coded as a cause due to a tree. Q. Caused due to a tree, but it includes adverse weather. I guess A. (MacMullin) Yeah, I hear you. Q. Yeah. A. (MacMullin) So there's the way we look at ou...

AI summary The discussion revolves around outage coding practices, specifically how outages caused by trees are distinguished from those caused by adverse weather. The witness explains that outages are categorized based on cause codes, and while some are due to tree contact, others may be due to weather or other factors, and these are tracked separately.

1 that's correct. Forty (40) percent of outages that would 2 have been coded as adverse weather would have been 3 subsequently updated to be shown to be reflecting a tree 4 contact cost code. 5 Q. So the adverse weather line would 6 be wit...

AI summary The discussion addresses the reclassification of outage causes, specifically moving 40% of adverse weather outages to tree contact causes. It also covers Nova Scotia Power's evaluation of a pooling arrangement for spare transformers, with the last assessment conducted in 2024.

NS POWER PANEL 149 Cr-ex, (Powell) 1 So, again, stats are valuable for 2 understanding, but when we're looking at the overall 3 results of the program, we are absolutely seeing a 4 significant improvement in the reduction of outages due to...

AI summary The discussion highlights improvements in reducing outages due to trees as a result of investments in the Vegetation Management Program. However, the speaker notes that the data reflects a subset of feeders targeted for vegetation work, which are those with a history of outages. The timing of work completion also affects the realization of benefits in the same calendar year.

NS POWER PANEL 443 Questions, (Murphy) 1 So I do want to take that away. 18 outages caused by tree contacts, customer hours of 19 interruption by tree contacts, and customer interruptions INTERNATIONAL REPORTING INC. CERTIFIED COURT REPORT...

AI summary The text discusses a regulatory proceeding involving Nova Scotia Power, focusing on outage data related to tree contacts and MEDs/EEDs from 2020 to 2024. The discussion includes confirmation that certain years (2021 and 2024) had no MEDs or EEDs, and the use of a table to summarize responses from International Reporting (IR) documents.

NS POWER PANEL 517 Questions, (Chair) 1 Q. If we can is there sort of a 2 reflexivity between D005, which is the planned, and the 3 D055 which is planned and D005, which is the unplanned? 4 Is there reflexivity between the two? In other wo...

AI summary The discussion focuses on the relationship between planned (D005) and unplanned outages, noting that increasing planned replacements could reduce unplanned ones over time. It also highlights potential increased operational costs from reactive responses to unplanned outages, such as overtime labor.