Electrical power was cut off for short periods yesterday for some Georgetown residents and businesses, and may be cut off temporarily again today, because of a construction accident in which a pile was driven through one of two electrical feeder lines, according to an official of the Potomac Electric Power Co.

The spokesman said because of the accident, only one line was available to service the Georgetown area, and that during peak demand power was cut off for about 800 customers at a time for up to two hours. The accident occurred in the 1000 block of 33rd Street NW.

Service was resumed for the entire Georgetown area at 4:30 p.m. yesterday, the spokesman said. But power may have to be shut off in sections of the area again today until another line is placed in operation.

The area affected includes Columbia and George Washington University hospitals, the Kennedy Center, the Watergate complex, and extends westward from Washington Circle to the area of Georgetown University. The university was not affected, however. The outage extended to the Potomac River and north to Reservoir Road,it was reported.

The spokesman said the hospitals and the Kennedy Center did not lose power during the outrage, but that building officials were asked to reduce the amount of electrical energy being use there.

"We will have to keep monitoring the lines and we may have to reinstitute the procedure (of shutting offpower for certain areas) if we have too much demand," said Pepco spokesman Doris Newcomb.

A second line is expected to be operation by 6 o'clock tonight, Newcomb said.*