SOUTH BEND -- American Electric Power Co. is scheduled to replace four more underground transformers this week as it continues to upgrade the downtown power grid.

Electricity to the four transformers will be turned off about 3 a.m. each morning this week until Thursday. Power is expected to be restored by 6 a.m. each day. No businesses or residences are expected to lose power.

The four locations are:

Lafayette Boulevard just north of Colfax Avenue on the west side of the street.

The southwest corner of St. Joseph Street and Jefferson Boulevard in front of KeyBank.

The southwest corner of Washington Street and Lafayette.

The northeast corner of St. Joseph and Wayne streets.

Since it takes two to three hours to replace a transformer, a section of street at each location may be blocked for a short time.

All the transformers will be hooked to the new Studebaker substation, which was recently constructed on Main Street just north of Sample Street.

The work is part of an $18 million project to replace the 34,500- volt underground South Bend electrical system that serves downtown businesses.

The aging system came under fire during the last year after several transformer explosions downtown left some customers without electricity on several occasions. Fires resulted from some of the explosions.

Since April 1 last year, AEP has installed more than 9,000 feet of new duct work and more than 38,000 feet of new wire. There have been 23 transformers replaced, all powered by the new substation.