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Rochester Substation

Rochester Substation, Rochester, NH

Modifications to Existing 115kV Substation

A new 115kV switchyard adjacent to Rochester Substation was under construction and (2) existing 115kV lines were to be re-routed from Rochester, to a new switchyard, called Eastport.  The scope of the Rochester project included the electrical and P&C removals and additions required in Rochester, the cut-over of the (2) lines, and the design of the strain buses connecting Eastport Substation to the transformers at Rochester Substation.  Remote work required at the Deerfield and Madbury Substation terminals was also part of this project.

Engineering, Design, and Procurement and Construction Support Services Included:

  • Design of the strain buses between the yards, including the dead-ends and line work
  • Coordination of re-routing the (2) incoming 115kV lines from Rochester to Eastport
  • Removal of the bus tie, breakers, and disconnect switches at Rochester
  • Removal of the line protection and control schemes at Rochester, and transfer of the systems to the new Eastport protection schemes
  • Modification of the existing 115kV bus in Rochester to the (2) transformers, and the design of bus support structures, as required
  • Addition of the new circuit switcher and CT on the high side of the 115/34.5kV transformer
  • Addition of the circuit switcher failure relays and a cabinet to house the new P&C relays and devices
  • Procurement of the new circuit switcher, circuit switcher failure and lockout relays, test switches, permissive switches, aux relays, new Hoffman Cabinet and lamps, terminal blocks, and fuse blocks, as required.

Realtime’s responsibilities included the design and engineering of the re-routed line terminals; strain bus between the yards; design of the dead-end structures and foundations; re-design/check of the ground grid and lightning protection systems; and design on the conduits and/or trench systems between the yards for routing cables.  Engineering provided studies and analysis, as required, for the lightning protection and ground grid design, and civil/structural analysis of the new steel structures and foundations.

Engineering also provided miscellaneous procurement services, as listed above, and construction support services, including review of all shop drawings and trade prints.  Realtime assisted with bid packages, bid evaluations and procurement activities, vendor RFIs, field construction issues and RFIs, and preparation of as-built drawings and documentation for project closeout.