Topic:"Infrastructure Planning" in M03715

Why do this project this way? Purchasing a spare transformer will increase the capacity of the Kempt Road Substation along with providing an energized and tested spare unit in the event of a transformer failure. The remaining unit has been...

AI summary The project involves purchasing a spare transformer for the Kempt Road Substation to increase capacity and mitigate risks from potential transformer failure. The existing unit faces similar conditions, increasing its failure risk. NSPI will execute this work.

NON-CONFIDENTIAL 1 Response IR-4: (cont'd) 2 3  transfer 23 MVA from T63 onto 1H Water St, 4  transfer 13 MVA from T63 onto T62: 5 6 Based on these considerations, the revised load would be served as follows: 7 8 Kempt Road 9 104H-T61 =...

AI summary NSPI proposes transferring 23 MVA from T63 to 1H Water St and 13 MVA from T63 to T62, adjusting load distribution across substations. If all three transformers at Kempt Road fail, NSPI's plan would face capacity limitations due to feeder and substation constraints, requiring additional offloading.

CONFIDENTIAL (Attachment Only) 1 Request IR-16: 2 3 With reference to the response to IR-3 (b), it is stated that a transformer was taken from 4 another location and placed in-service at Kempt Road: 5 6 (a) Where was this transformer taken...

AI summary NSPI's response to IR-16 details that a transformer was moved from the non-operational Dartmouth Crossing Substation (expected to be in-service by December 2011) and specifies its voltage and MVA rating. The response does not address future relocation plans or energized spares criteria.

CONFIDENTIAL (Attachment Only) 1 Response IR-17: (cont'd) 2 - 3 (d) The unit located at Onslow is the only system spare capable of being connected to 138-25 - 4 kV. Date Filed: March 29, 2011 NSPI (UARB) IR-17 Page 2 of 2

AI summary The document states that the Onslow unit is the only system spare capable of connecting to 138-25 kV. Filed by NSPI (UARB) on March 29, 2011, as part of IR-17, this technical detail highlights infrastructure limitations relevant to regulatory proceedings.

NON-CONFIDENTIAL 1 Request IR-18: 2 3 With reference to the response to IR-5: 4 5 (a) When were the investigations noted in IR-5 (a) completed? 6 7 (b) When did NSPI start to use the procedure described in IR-5 (b)? 8 9 (c) Please describe...

AI summary The text discusses responses to regulatory inquiries regarding transformer failures and fault current limitations. NSPI provided details on past investigations, the timeline for implementing procedures, and design limitations related to fault current. It also addresses options for mitigating fault current and the status of a third transformer.

CI # 40425 Kempt Road Transformer $1,093,699 Board staff issued Information Requests ("IRs") on December 24, 2010 and February 21, 2011, to which responses were received by the Board on January 27 and March 29, 2011, respectively. The Boar...

AI summary The Board approved NSPI's request for funding to purchase a fourth transformer for the Kempt Road Substation to improve power supply reliability in downtown Halifax. The Board expressed concerns about insufficient project details and the outdated status of the spare transformer report, but accepted the request due to urgency and alignment with Hydro One guidelines.

IR-1: On page 4 of 20, under "Why do this project now?", NSPI states this project is being advanced at this time to reduce the probability of loss of load due to a transformer failure. Please provide specific information to support the abo...

AI summary NSPI's project aims to reduce transformer failure risks by advancing the work now. The Board requests justification for submitting this as a U&U work order instead of the 2011 ACE Plan and details on the 2010-2011 work schedule. Additional queries focus on substation configurations and contingency capacity.

- b) Which corrective measures and/or procedures have been developed by NSPI to decrease the probability of future transformer failures at this substation? 1 IR-6: 2 On page 4 of 20, under "Why do this project", NSPI states: 3 4 It is expe...

AI summary The document outlines a series of inquiries regarding corrective measures and procedures developed by NSPI to reduce the likelihood of future transformer failures at the Kempt Road substation, including requests for documentation, transformer age and life expectancy, spare transformer availability, cost breakdowns, and alternative solutions.

IR-16: With reference to the response to IR-3 (b), it is stated that a transformer was taken from another location and placed in-service at Kempt Road: - a) Where was this transformer taken from? - b) What is the rating of this transformer...

AI summary The IR-16 inquiry seeks details about a transformer's relocation, its specifications, future placement, single line diagrams, and NSPI's policies on energized spares and planning criteria.

IR-17: With reference to the response to IR-4: - a) As it relates to the hypothetical loss of all three transformers at the Kempt Road Substation, how much of the stated 54 MVA could not be transferred to the Armdale and Water Street subst...

AI summary IR-17 requests detailed technical information about transformer capacity limitations, substation diagrams, mobile transformer capacity, and spare equipment availability following a hypothetical loss at Kempt Road Substation. Questions focus on transfer capacity constraints, documentation requirements, and equipment specifications.

IR-19: With reference to the response to IR-6: - a) Describe any test results regarding the integrity of this third transformer. - b) On page 4 of 20 of the submission NSPI states: liThe remaining unit has been exposed to similar condition...

AI summary IR-19 queries NSPI on test results for a third transformer's integrity, risk assessment of a unit post-procedure, reinforcement measures for transformer integrity, and cost comparison between enhancements and replacement.

IR-26: With reference to the response to IR-14: - a) Please explain why 5 additional circuits are needed to provide sufficient transfer capability for the Kempt Road Substation load. - b) Provide a copy of NSPl's long range planning study...

AI summary IR-26 requests NSPI to explain the need for 5 additional circuits at Kempt Road Substation and to provide their long-range planning study for the Halifax Peninsula, including next steps for addressing increased load growth. This follows the response to IR-14.