Deerfield Substation Project

In the Fall of 2009, PSNH will install a new transformer at the Deerfield Substation on Cate Road in Deerfield.

The Deerfield Substation is a transmission substation that interconnects three 345kV (345,000 volts) lines, which extend to Derry/Londonderry, Newington and Buxton, ME. The substation currently has one 345/115-kV autotransformer to supply the four 115 kV lines that leave the substation, and extend to Bow, Rochester, Hooksett and Madbury.

As demand for power in New Hampshire’s Seacoast and Merrimack regions continues to grow over time, the existing autotransformer at Deerfield will reach its capacity. Therefore, additional transformation is required to meet that demand and to increase overall system reliability. An additional transformer will also serve as a backup in the event that the existing transformer fails.

New circuit breakers will also be installed to minimize service interruptions, and selected sections of transmission lines that connect with Deerfield Substation will be upgraded. The new transformer will be delivered by rail into the City of Manchester and then be transported to Deerfield by Heavy Hauler through Hooksett and Candia. The work is expected to take place during the end of August - early September.

This page will be updated as the Deerfield Substation Project develops.

To learn more about PSNH's Deerfield Substation Project, please browse through the following documents:

• Schedule - 115kV Breakers (PDF File Format 43KB)
• Schedule - Auto Transformer & 345kV Breakers (PDF File Format 74KB)
• Information for Deerfield Selectman, 07/13/09 (PDF File Format 103KB)
• Deerfield Aerial Additions 1 (PDF File Format 461KB)
• Deerfield Aerial Additions 2 (PDF File Format 467KB)
• GoldHAttachment 3 (PDF File Format 1.99MB)
• T1023C Deerfield Town Gantt (PDF File Format 86KB)

Please direct all comments to:

Note: To view these PDF files, Adobe Reader is required.