We have come to expect that if we lose electric
service it will be restored within a few hours at most. But when a devastating
event, like a tornado, ice or snow storm causes major damage to a co-op's
system, longer outages cannot be helped. Crews work long, hard hours restoring
service, but it's a task that needs to be done methodically to be done
safely.
Every electric cooperative follows a basic principle when it comes to
restoring power - priority goes to the lines that will get the most people back
in service the quickest. This usually begins with main lines from the
substations that can affect 200-600 members, and continues out to tap lines,
which may affect 30-200 members, and then to individual service lines affecting
just 1-5 members. |
A major storm has just hit the cooperative. Here's a simplified look at
how the co-op typically goes about the task of restoring electric service.
Step 1: The substation is energized
but a main distribution line is damaged near the substation, leaving most
members without power. All repairs start with the main line.
A large number of members (shown with |
orange arrows) will have power
returned once the main line is fixed. All other repairs would be pointless
until this line is restored as it feeds all the other lines. |
|
Step 2: With the main line
restored (now shown in red), the line crew can isolate other damage and
prioritize repairs. Though a couple of repairs were closer, fixing the line
that serves this subdivision down the road will get a larger number of
consumers on more quickly.
Step 4: A smaller
tap line serving a number of homes and the farm on the hill is next on the list
for the line crew. The move probably doesn't make the folks in the blue house
too happy. They've seen the crew driving by their home and working right across
the road. They see lights on in homes of all their neighbors but they don't
have power!
Step 5: Only after the tap
lines are repaired does the crew start work on individual service lines. The
crew has been past the blue home three times and could have stopped to restore
power anytime after the first main line was repaired and electricity was
flowing to the pole nearby. But it's not fair to other members for a crew to
spend hours fixing one outage, when the crew can move down the road and restore
power to dozens of homes in the same amount of time.