Getting Back On Line

OPPD customers have come to expect that if they lose electric service,  it will be restored within a few hours at most. But when a devastating event like a tornado, ice or snowstorm causes major damage to the electric system, longer outages cannot be helped. Crews work long hours restoring service, but it's a task that needs to be done methodically to be done safely.

Every electric utility follows a basic principle when it comes to restoration: priority goes to the lines that will get the most people back in service the quickest. This usually begins with the main lines from the substations, which can affect 200 to 2,000 customers, and continues out to tap lines, which may affect 30 to 200 customers, and then to service lines affecting one to five customers.

Suppose a major storm has just hit this electric utility's system. Here's a simplified look at how OPPD typically goes about the task of restoring electric service.

Step 1:

The substation is energized, but a main distribution line is damaged nearby, leaving customers without power. Repairs start with this line. A large number of customers (arrows) will have power restored when it is fixed, but other repairs would be pointless until power is restored to this main line. In this storm, a large number of customers did not have power after the main line was restored. 

Step 2:

With the main line restored, the line crew can isolate other damage and prioritize repairs. Though a couple of repairs were closer, fixing the line that serves the subdivision down the road will get a larger number of customers on more quickly. 

Step 3:

Moving back down the road to fix this tap line will restore electricity to the homes marked with arrows.

Step 4:

A smaller tap line serving several homes and the farm on the hill is next on the list for the line crew. The customers in one house may have seen the crew driving by their home and working right across the road. They see lights in homes of all their neighbors, but they still don't have power. That's because even though electricity is coming to their pole (that happened with the repair in Step 1, 2 or 3), the service line from their pole to their meter is damaged. Individual repairs come after all distribution and tap lines are restored.
 

Step 5:

Only after the tap lines are repaired does the crew start work on individual service lines. It's more economical to first repair the lines that will restore power to the most people.
 

Have you ever wondered where OPPD's lines stop and your lines begin? Please read Facts about your Residential Service Connection.