More than 4,000 people working on restoring service to PPL Electric Utilities customers in the aftermath of Hurricane Sandy are making significant progress.

Up to 85 percent of PPL's customers without electricity should have power restored by Friday evening.

The majority of most communities have regained their power, although thousands are expected two be without power for a few more days.

The eastern part of the company's service territory, which includes parts of Bucks and Montgomery counties, the Lehigh Valley and north into northeast Pennsylvania, should have the last of its customers restored by 11 p.m. Sunday, says PPL.

PPL says as of 1 p.m. Thursday, service has been restored to 175,000 customers through a systematic approach that focuses on public health and safety facilities and initially making repairs that restore large numbers of customers to service.

"We made progress on the first full day of restorations Tuesday and we can assure all of our customers that there will be no let up in our determination to get everyone restored as safely and as quickly as possible," said Dave Bonenberger, vice president of Distribution Operations for PPL Electric Utilities. "We are working around the clock to assess and repair damage to equipment across our 10,000-square-mile service territory."

Bonenberger said the company's work plans for today would, if all goes well, restore service to 70,000 customers.

"We expect that between 80 and 85 percent of customers who lost power because of this storm will have service restored by 11 p.m. Friday," Bonenberger said.

Utility officials said the last of the affected customers in the Harrisburg and Lancaster regions should have power restored by 11 p.m. Thursday.

An extra 150 utility workers are expected to arrive today from the Deep South, putting the total at more than 2,700 including PPL Electric Utilities' physical workforce of about 500. Help has arrived from at least a half-dozen states including Kentucky, Florida, Wisconsin, Georgia and Missouri.

PPL Electric Utilities' power restoration strategy has been developed and improved with experience from previous major storms, and mirrors procedures used at other large utilities that also have dealt with substantial outages.

According to PPL, the restoration strategy is as follows:

Ÿ Its first priority is taking care of unsafe situations, such as downed wires, and restoring critical public safety facilities like hospitals.

Ÿ It then focuses on major power lines and substations that serve large numbers of customers. Where it can, PPL uses switches to reroute power to as many customers as possible until repairs can be made.

Ÿ PPL gives higher priority to repairs that will get the largest numbers of customers back in service as quickly as possible.

Ÿ PPL then restores power to smaller neighborhoods and individual homes and businesses.

Many emergency services are utilizing many methods of informing people affected by the power outage. PPL's Facebook page routinely posts updates to area outages and has PPL representatives answering questions online, as people are able to use Facebook on their cell phones. In Hometown, residents were notified via a bullhorn on a fire police vehicle as it drove through the affected areas. In West Penn Township, neighbors with power could be seen knocking on doors and calling those affected.

As of 10 a.m. this morning, PPL's website shows 196,828 of their Eastern Pennsylvania customers still without power. Some of the affected counties include Carbon (with 6,677 customers without power), Schuylkill (4,325 customers), Lehigh (64,703 customers), Monroe (24,434 customers) and Northampton (31,175 customers).

The widest areas affected in Carbon County are Penn Forest Township, 2,152 customers; Towamensing Township, 1,163 customers; Kidder Township, 779 customers; and Mahoning Township, 753 customers.

PPL's website this morning lists the number of customers without power in Rush Township, 5,409 Rush Township customers have been restored. Also listed was West Penn Township, with 594 customers without power, about one fifth of the initial total.

Customers who have not yet reported outages are asked to call 1-800-DIAL-PPL (1-800-342-5775) or report online at www.pplelectric.com. The outage web site is adapted for mobile phones.