For Gary Hammond, cutting electricity use by 10 percent at the McCrory's variety store he manages meant a few less customers yesterday.

"People look in and see some of the lights off and think we're closed," he said. "I guess they'll get used to it in a couple of days."

It was like that all over western Maryland and adjacent corners of Virginia and West Virginia yesterday, where a mandatory 10 per cent power cut went into effect for business and industrial customers of Potomac Edison Co. The small utility, which serves 240,000 rate-payers in the three-state area, is down to what utility regulators call "potentially dangerous" levels of coal reserves -- in fact only enough to power it generators for another 25 days.

With no end in sight to the long coal strike, public service commissioners ordered 10 per cent reductions in use beginning yesterday for Potomac Edison customers. In Frederick, there was little change since the utility has been pleading for conservation in radio and newspaper ads for the last two weeks.

Meanwhile, officials and industries have begun planning to implement the next steps ordered in Maryland for March 2: a 20 per cent cut in power use by local governments and commercial users and a 30 per cent reduction in industrial use.

Virginia and West Virginia businesses and industries will both be required to make the 30 per cent cut on March 2, while more drastic cuts -- to "plant protection levels that will merely keep equipment from freezing --states.

That could mean school closings, doused street lights and an increased crime rate, according to officials of several jurisdictions. It would certainly mean layoffs in the region's industries, they said, although the full extent of the impact is still uncertain.

"Even though our lights are low, our merchandise is bright as sunshine," reads the hand-lettered sign on the corner door of Allen's, a gift shop here. Owner Sanford Blum, head of the Downtown Retail Merchants' Association, said the 60 stores and banks in the group had been cutting electricity use by 25 to 50 per cent for the past two weeks, but are worried about the aftermath.

We're stuck with a power shortage while the rest of the state is fairly well secure," he said. "We worry about the prospect of the bills we'll be paying. Are we going to be cut back (in power use) by 20 per cent and still pay the same as we did at full power?"

There's a good chance that they will, according to Potomac Edison president John M. McCardell. "There'll be substantial increases in the rates, and I doubt if there'll be any big reductions in the bills," he said. Rates will have to rise to pay for the 42 per cent of its output that Potomac Edison is now buying from other utilities, which produced it on oilburning plants that are more costly than coal-burning ones.

The Frederick School Board met yesterday to discuss limiting classes to either half days or three days a week beginning March 15, with full shutdown a possibility March 20 for the area's 20,000 schoolchildren.

Police Chief Richard Ashton said he would beef up night shifts when the 30 percent power cutbacks occur, and sooner if necessary. "At this low (10 percent reduction) level we're in pretty good shape, but there's a great possibility of an upsurge in criminal activity later on," he said.

Mayor Ronald N. Young said many people seem to be ignoring the whole thing. "Theres a certain amount of skepticism on the severity of the situation," he said.

At Frederick Towne Mall, where work has begun to open the roof for a skylight, some storekeepers liked the softer lights. "To tell you the truth, it's kind of peaceful this way," said Hickory Farms store manager Diane King. "I could get used to it."