All of Turner and Buckfield and parts of Livermore and Leeds will lose power for up to six hours beginning at 12:01 a.m. Sunday so Central Maine Power Co. can work on upgrades.

In Livermore, power will be cut to Auburn Road (Route 4), Bunker Hill Road, Bear Mountain Road, Route 108 and Norton Road. In Leeds, it will be cut to River Road, North Turner Bridge Road, Fish Street and Sedgley Road.

About 3,400 customers will be without electricity while CMP adjusts the voltage settings on all of the transformers in the area and completes other improvements. The work will be done by 50 line workers, 25 bucket trucks and 10 support personnel, one of the biggest crews CMP has ever assembled for a single improvement project.

The upgrade in Turner is the first of two major projects to enhance reliability in the area. The second will begin next year with the construction of a new substation in Leeds. Sunday’s upgraded lines will connect to the substation, adding flexibility to the system and allowing the company to restore power more quickly after storms or other problems, CMP said.

This weekend’s work is expected to be complete by 6 a.m. Sunday. In case of bad weather, the work will be done Sunday, Sept. 7, during the same hours.