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Bridgewater Substation

Bridgewater Substation, Bridgewater, MA

Multiple Substation Upgrades

This project included (2) separate project scopes:
• The Bridgewater Upgrades Project
• The Bifurcation of the E1 Line at Bridgewater Substation

Associated projects included Somerset and Belmont Substation work. Remote ends relay upgrade work to match the relay upgrades at Bridgewater.

Overall Project Summary:

This project includes the installation of a new 345/115kV control house. Upgrade work in the 115kV yard includes replacing (4) breakers and upgrading terminal bus work for (2) lines. A new 115kV line, originating from Bridgewater Substation, is also included and requires the installation of (2) new 115kV gas circuit breakers. This will allow the splitting of the E1 line into two segments (E1 and a new A24 line). A new line exit and line construction is required to intercept and separate the E1 line. Upgrade work in the 345kV yard includes replacing (2) breakers.

Engineering, Design, and Construction Support Services Includes:
Foundations:
• 345kV Yard: Removal of the existing breaker foundations and installation of (2) new foundations.
• 115kV Yard: Re-use (4) 115kV OCB foundations for (4) new gas circuit breakers; and provide (3) CCVT support structure foundations for (3) 115kV line exit positions.
• Foundation for new control house is approximately 84’ x 64’.
• 115kV Yard: (3) new single phase support structures for CCVTs; (3) 115kV surge arrestors on the North Bus; (3) 115kV surge arrestors on the South Bus; (3) 115kV surge arrestors on the transformer bus.
• 115kV Yard A24 Line Extension: Addition of a new bay to serve as the line exit location, which includes foundations for (5) 115kV disconnect switches; (2) A-frame pull-off structures with LA & CCVTs; and (9) single phase bus supports.

Electrical Work:
• New 345/115kV prefabricated control house designed and installed with HVAC, auxiliary AC distribution system, P&C systems, and 125V DC systems.
• (4) 115kV breakers to be replaced.
• Upgrade G18 and F19 line traps and terminal bus work.
• Install a new 115kV bay to supply the new A24 line.
• Install (2) new 115 kV GCB’s with disconnect switches and new CCVT.
• (2) New 345kV, 3000A, 50kA gas circuit breakers.
• (5) New motor operated disconnect switches.
• (4) New 3000A, 63kA gas circuit breakers.
• (2) New 3000A, 63kA gas circuit breakers for the new A24 line.
• (5) New 3000A disconnect switches.
• (8) New 3000A disconnect switches.
• New line trap on G18 and F19.
• Conductors will be upgraded for line exits F19 & G18.
• Addition of new 115kV bay extension for the new A24 line, which includes (3) new CCVTs; (3) bushing potential devices will be retired; (1) CCVT .

Secondary Electrical Work:
• New relay and control switchboard panels, AC station service, DC station service, DFR, communications equipment, and control cables.
• New pad-mounted transformer and back-up generator will be located external to the new control house. New automatic transfer switch and distribution panels.

Removals and Retirements:
• Remove and scrap (2) 345kV ACGs, (4) 345kV disconnect switches, (1) 345kV circuit switcher, (4) 115kV OCBs, and (9) 115kV surge arrestors.
• Remove the E1 line bifurcation 115kV structure and (7) ground 115kV switches.