What happens when the lights go out?

Many Washingtonians have asked that question since a severe thunderstorm tore through the area two weeks ago, knocking out electrical power to more than 130,000 residences or other customers of local utility firms.

The summer storm of June 27 carried with it winds of up to 80 miles an hour and lightning that tore into electrical transformers.

Although about 30,000 customers of Virginia Electric & Power Co. in Northern Virginia suffered power blackouts as the storm passed through the metropolitan area, all but 800 had their lights back on within 24 hours.

On the Washington and Maryland side of the Potomac River, a larger region served by Potomac Electric Power Co., the storm was more severe and more customers suffered blackouts and for longer periods of time.

It was hot and humid here on June 27 and in the days threafter, as Pepco struggled to restore service. About 100,000 Pepco customers had some power failure; 1,500 customers had no power 30 hours after the storm and some had no lights for three days.

Now, a hot controversy has been stirred by allegations that Pepco discriminated against some neighborhoods in restoring service and in taking so long to do it. The D.C. Public Service Commission has scheduled hearings on Pepco's handling of the crisis and there have been suggestions that the utility should be responsible for damaged caused by the absence of power - such as spoiled food.

The storm did provide an unusual glimpse into how a private business responds to critical situations, and Pepco officials, at the request of The Washington Post, have detailed a thronological record of company actions since employes first were notified of power failures.

Although individual customers suffered losses from the absence of power, the cost of Pepco of restoring lines and repairing transformers will be some $750,000, according to Walter Johnson, manager of electric systems operations.

Johnson said the storm damage was the most severe suffered by Pepco in 20 years. Restoration of power took so long because the damage was widespread throughout Pepco's service area.

Instead of knocking limbs into power lines, the storm knocked down entire trees throughout the District and parts of Montgomery and Price George's counties. To remove a tree from a power line requires two or three times the manpower needed for just one limb, Johnson said in an interview.

"We had a lot of frustration on the part of many customers," Pepco senior vice president recalled. "We had an embassy call and allege that we discriminated against foreigners. Someone else called and said we don't give a damn about people with plained we discriminated against businesses."

The June 27 storm hit Pepco, as well as the entire area, without warning. And that was one major factor that affected the firm's response. Normally, if a storm is expected, some of Pepco's service personnel are kept on duty, Johnson said. But there was no warning on June 27 from any of Pepco's weather sources - the National Weather Service, a private weather service or neighboring utilities. So when the storm first hit at 7 p.m. in Montgomery County, most Pepco employes had gone home.

Immediately, when the storm hit, phone calls reporting lights out began to pour in to Pepco. At 7:15 p.m., the company called all its service personnel back to work. The next morning, as the process of restoring power dragged on, vacationing employes were asked to return to work.

As the storm passed into the District and out through Prince George's County that Tuesday evening, a deluge of calls swamped the phone circuits at Pepco's building downtown on Pennsylvania Avenue NW. Sixty operators were calls in to handle the deluge. Despite a system which can handle 90 callers (30 on hold), some people got a busy signal. By Friday morning, the operators had handled 51,485 calls related to the storm, Johnson said.

As the operators answered the thousands of complaints, about 500 servicemen - double the normal daily amount - worked to restore electrical circuits knocked out by the storm. Because the damage to Pepco's system was so extensive, the company asked for help from other utilities.

None of the neighboring utilities could spare any manpower at first because they, too, had been hit by the storm. But early Wednesday, Pepco finally got help with about 50 crews (two or three workers each), from utilities in Shenandoah, Va., Salisbury, Md., and Richmond. On Thursday, some crews from Philadelphia arrived.

Pepco repairmen worked 16-hour shifts Wednesday and Thursday. Repair crews were assigned to work throughout Pepco's service area, with a goal of "restoring service to the maximum number of customers in the shortest amount of time," Johnson stated.

The June 27 storm knocked out about 550 of Pepco's 1,200 main distribution lines. Each of those lines, which lead out of a substation, can serve as many as 3,000 customers in a residential area.

Of the 550 main lines knocked out by the storm, 170 had power interrupted along the entire length. The rest were interrupted only partially, as the damage on them was located where a fuse prevented damage to the rest of the line.

Pepco's top priority after the June 27 storm was to repair the 170 lines where the power was totally out, Johnson said. Electrical service along all those lines was at least partially restored within 24 hours.

Once all the main distribution lines had some electricity flowing through them, Pepco crews were assigned to repair those lines serving a lot of customers - an apartment building or many houses. Location or neighborhood played no role in these decisions and this task was accomplished by Thursday evening, Johnson said. Then, a smaller thunderstorm rolled through, doing little damage compared with the Tuesday storm.

By Thursday night, Johnson said, the Pepco repair crews were able to repair isolated trouble areas - places where the damaged wires served only a few customers.

On Friday, Pepco advertised on television and radio stations, asking customers still without power to call the company. About 150 customers called Johnson said. "The last services were restored by midnight Friday, except a few small office buildings," he added.

Even after service had been restored to all customers, Pepco had much work to do, because some of the repairs had been temporary. Permanent repairs were completed in about ten days, hurried by the need to have the power system in top condition during the summer, when air conditioners impose a heavy load on Pepco's system.

In response to complaints from some Pepco customers who were without power for three days after the storm, the D.C. commission has scheduled a hearing next week to air the matter. Commissioners said the hearing was not to quiz Pepco on how it restored power, but to hear from people who suffered extended power interruptions. The hearing will be at 10 a.m. on July 21 in room 314 of the commission's offices, 1625 I St. NW.