Crews from ElecComm Corp., an electric- and communications-line construction company based in Wil­mington, are running new copper power lines through the existing manhole and duct system in Beverly, Manchester-by-the-Sea, and Gloucester, along Route 127 and also some side streets.

The work is part of a nine-month, 15-mile, $11 million project that also will improve National Grid’s electrical infrastructure in Essex, Hamilton, Rockport, and Wenham, according to utility officials.