LEWISTON — Years ago, powering on a $57 million, 345,000-volt electrical transformer might have involved engineers pulling a big switch, Central Maine Power President and CEO Sara Burns said.

Thursday morning, it just took a couple of pushes on a computer touchscreen. Burns did the honor and, with an audible hum like an air conditioner turning on, Maine’s electrical grid became more reliable, she said.

“As easy as that,” Burns said.

Burns and CMP officials powered the massive 750,000-pound Lewiston autotransformer for the first time Thursday morning. The new Larrabee Road substation is one of the linchpins in CMP’s $1.4 billion Maine Power Reliability Program. Thursday’s move was significant for one big reason, Burns said.

“When we energize today, we make the system more reliable,” Burns said. “Up until this point, we’ve just been building — doing construction. But this is the turning point in reliability, and from this day forward, the project will continue to strengthen the system in Maine.”

With the push of a button, motors rotated three T-shaped connectors into place, linking the new autotransformer to the rest of the 345,000-volt system. With a second push, Burns powered up the transformer.

Outside in the CMP yard, the machine made a clank like the tailgate on a truck closing. Inside the substation’s control center, a barely perceptible hum could be heard.

Burns said the new operation shouldn’t be any more noticeable to Lewiston residents or to anyone else in Maine.

“It’s not going to change things today in a way people will notice,” Burns said. “It’s about investment in the system. This is built to support the future of development in Maine, of jobs and growth.”

The autotransformer will reduce the voltage along CMP’s network from 345,000 volts to 115,000 volts, making it suitable for delivery to the central Maine region.

Through its Maine Power Reliability Program, CMP is upgrading a swath of power lines through central Maine to connect to lines from Canada. They pass through Litchfield, Monmouth, Leeds, Greene, Lewiston and a corner of Auburn at the Durham line.

Work in Lewiston should be finished this summer, Burns said. Elsewhere in Maine, quite a bit of work remains to be done, she said.

“Lewiston is really a strategic spot,” said Bill Sawyer, project manager for the Maine Power Reliability Program. “It’s the point where a lot of the existing lines are already in place. There are 115-kilovolt lines that head west to the Oxford-Norway area, one that heads east to the Augusta area, two that head south to Lewiston and one that heads north to Livermore Falls-Rumford.”

Two more 115,000-volt lines are to be built this summer, including a second line to Livermore Falls-Rumford and another line to Lewiston that is still being reviewed by the Maine Public Utilities Commission.

The program involves four years’ worth of construction, erecting 442 miles of transmission lines across 75 Maine cities and towns. The entire program should be finished by 2015, with work in Lewiston wrapping in 2014.

Once CMP’s work is done this summer, most of the activity at the Larrabee Road site will end. It will be closed and ringed with a security fence.

The system is designed to be fully automatic, Sawyer said. Crews will come by to inspect it occasionally, but there should be little need for regular staffing.

staylor@sunjournal.com

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