A $29 million distribution system upgrade project for Greenwich, Connecticut, by Connecticut Light & Power (CL&P) provides redundant electric service to the North Greenwich distribution substation, thereby improving reliability to the customers it serves.

A new overhead feeder circuit at 35 kV is being installed between a substation in Cos Cob, CT, and the North Greenwich substation about 7 mi away. The new circuit consists of a fully insulated aerial cable approximately 5 inches in diameter having a copper jacket. John Siclari, project manager, Greenwich Infrastructure Upgrade, said, “With time the jacket will turn green and blend right into the background.”

To install the new cable, all the wood poles along the route must be replaced with taller, bigger poles in order to gain the necessary safety clearances above the public right-of-way and communication circuits installed on the same poles. Currently, the existing poles support a 13.2-kV distribution circuit on crossarms at the top with cable TV and telephone circuits below. In all, 315 poles are being replaced.

The aerial cable is being installed between the distribution circuit and the communication circuits. Once CL&P has completed the installation of the new cable and moved the existing power facilities to the new poles, the communication utilities will move their equipment to the new poles.

Commenting on the rationale for the work, Siclari said, “Currently, we have underground feeders to the North Greenwich substation. Should these fail, the new aerial cable will improve reliability by providing a back-up supply to this substation.”

He added that the project, which began in September 2011, is within budget and on schedule for completion around June 1, 2012.