Auburn Street Substation

Auburn Street Substation, Whitman, MA

Substation Upgrade and Line Tap Relocation

Project scope included the install of a second auto-transformer and expansion of the existing 115kV south yard, requiring the temporary relocation of 345kV lines (Line 335 and Line 342), to temporary structures. Relocation of the Utility’s 115kV lines (Line 191 and Line 194) was also required.

In the 345kV Yard:

  • Additional 345kV bus and (8) new 345kV SF6 gas circuit breakers with associated foundations to replace (3) existing 345kV GCBs.
  • (18) New 345kV motorized disconnect switches and removal of (2) existing 345kV disconnect switches.
  • (16) New 345kV CCVT’s with associated foundations and removal of (7) existing CCVT’s.
  • (4) New line traps and wave tuners and removal of (4) existing line traps and wave tuners.
  • (2) H-frame pull off structures and (4) lightning masts, with associated foundations.
  • (9) Surge arrestors.
  • Approximately 1,400 linear feet of new 345kV 3-Phase bus and removal of 700 linear feet of existing 345kV bus.
  • Jumpers, as required, to connect the various pieces of equipment in the 345kV yard.


In the 115kV South Yard:

  • (15) New 115kV SF6 gas breakers with associated foundations to replace (8) existing 115kV GCBs and (4) 115kV OCBs.
  • (39) New 115kV gang operated disconnect switches and (2) new 115kV MOD switches.
  • (25) New 115kV CCVT’s and removal of (5) existing CCVT’s.
  • (4) New line traps and wave tuners and removal of (2) existing line traps and wave tuners.
  • (40) Surge arrestors and removal of (6) existing arrestors.
  • Approximately 1,460 linear feet of new 115kV 3-Phase bus.
  • Jumpers, as required, to connect the various pieces of equipment in the 115kV yard.
  • New foundation and oil containment area for the new auto-transformer.
  • Modular cable trench (30”W x 16”D) from the control house to both 345kV and 115kV yards.
  • Schedule (40) PVC direct buried conduit between the cable trench and equipment to be hard wired.
  • Substation ground grid to augment the existing ground grid.
  • Galvanized steel and aluminum substation structures for the proposed equipment.
  • Pre-engineered steel Control House with general purpose lighting, emergency lighting, general purpose outlets, heating, ventilation, air conditioning, fire alarm system, hydrogen alarm system, and associated wiring.
  • Auxiliary and control equipment in the relay/control building.
  • Transfer switches, AC and DC power panels, and DC power battery units with disconnects and chargers.
  • Relay, control and communication panels, including SCADA, annunciator and DFR panels.
  • (2) Auxiliary power pad mount transformers, sized by the Client’s Engineering.
  • (1) Auxiliary power transformer to be powered from a tertiary winding on the main station power transformer. The second auxiliary power transformer to be fed from a medium voltage circuit provided by the Owner.
  • Diesel emergency generator adjacent to the Control House with an auto transfer switch rated for the full output.
  • Multi conductor power, auxiliary and control cabling, and fiber optic cabling between the yard and control house.
  • Permanent motorized sliding gate, including card readers and cameras.
  • Duct bank containing (6) 6” PVC conduits.
  • Removal of all pre-existing foundations in both the 345kV and 115kV yards.


Transmission Line Interconnect Work Scope:

  • Temporary relocation of 345kV lines (Line 335 and Line 342), to temporary structures in the 345kV yard.
  • Temporary relocation of the Utility’s 115kV, Lines 191, 194 and 451-536, to facilitate work.
  • All necessary switches, CCVTS, and line traps required for the temporary relocation.
  • (9) Concrete caisson foundations to facilitate final re-location of Lines 191, 194, A94, 451-563, C2 and F19.
  • Foundations for terminations of new underground on Lines E20, C3 and S9.


Engineering, Design, and Construction Support Services Includes:

  • Temporary rerouting of overhead transmission lines to minimize outage times.
  • Permanent overhead transmission line rerouting of 115kV lines from North Yard, to newly installed South Yard.
  • Permanent underground transition design for 115kV lines from newly installed South Yard, to existing transmission right of ways.
  • Trenwa trench systems for System 1 and System 2 control cables.
  • (2) Adequately sized (125) VDC batteries and charger systems.
  • (4) 208/120 VAC, (3)-Phase, (4)-wire AC panel boards for heating, lighting, ventilation, and general service; (1) essential service AC panel board.
  • Station service transformers with fused safety switches and auto-transfer switch.
  • 345kV and 115kV P&C Systems, RTU’s, and alarm annunciation.
  • Review of all shop drawings and trade prints.


Engineering, Design, and Construction Support Services con’t.:

  • Permanent transmission line redesign of existing 345kV lines (Lines 335 and 342), from existing series breakers, to newly installed 345kV ring bus.
  • Fencing, gate security, fence signage, interior road paving, and yard stone surfacing.
  • Control House foundation and equipment, support structure, and dead-end structure foundations.
  • Aluminum and steel support structures for electrical equipment, steel dead-end structures.
  • Control and Protection systems for installation in new control house.
  • Underground, concrete encased duct banks for new 115kV line getaways.


Engineering Studies and Design of the Following:

  • Substation safe grounding.
  • Substation lightning protection.
  • Substation switchyard lighting.
  • Substation rigid bus structures.
  • Substation AC station service.
  • Substation DC battery.
  • Outage plan support.
  • Civil/Structural analysis of foundations and support structures.
  • Structural calculations for the steel dead-end structures.


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