“How long is it going to take?” Those are familiar words to all who work in the electric industry. It’s the first thing people think when the lights go out. It doesn’t take long sitting in the dark to realize how dependent we are on electricity. How much it makes our lives better and easier.
The electricity you use travels a great distance and goes through several steps to get to your home. It starts with a power plant. Power plants use fuel to produce power. That fuel could be natural gas, diesel, coal, hydro, wind, solar or nuclear. A power plant typically produces voltages of less than 30,000 volts. That voltage needs to be “stepped up” so it can travel long distances. That process starts next door in the power plant’s substation and switchyard. In the substation, a transformer will step the voltage up to 345,000 volts, or sometimes higher, and send it out on transmission lines to another substation.
At the next substation, electricity starts to get closer to its destination. Here we start stepping the voltage down. In this second substation, a transformer will step the voltage down to 69,000 volts and send it out to smaller local substations.
These local substations are the final substation before the electricity reaches your home. Here it is stepped down, again with a transformer, to the 7,200 or 14,400 volts that can then be delivered to the poles outside your home. Once it arrives outside your home, it is stepped down a final time, yes, by another transformer. This final transformer will step the voltage down to 120/240 volts that operate all the devices that power your life.
What I just described is hundreds of miles of line and thousands of poles. That’s a lot of exposure for something to happen and cause an outage. Just like your home, our system has breakers. Our breakers (also called reclosers) help us reduce the exposure of the line and allow us to split our system into sections. Doing so helps limit the size of the outages and allows us to keep as many people on as possible. Breakers also help to protect equipment on the line. Ever wonder why your lights blink a few times before going off? That’s the breaker. They operate a few times trying to give the fault a chance to clear the line before they open for good.
Now that the lights have blinked, your breaker has opened, and the power is off. So what happens?
6:35 p.m.: Your local lineworker gets a phone call.
When I answer the phone, I’m told that we have an outage. My first question is, “Is this an individual or a line outage?” A line outage will be a large section of line and several people. An individual will be just a single transformer or pole. As I get ready to head out the door, I take a look at all of the information available to me through our mapping software. Caller comments, GPS coordinates, a list of members affected by the outage—all of this is right at my fingertips. I look for the closest breaker to the outage, because if I know what breaker has opened, I have a good idea of where to start looking for issues.
7 p.m. The drive
An after-hours outage requires your lineworker to respond from home. Heartland’s service area stretches north and south from just outside Paola to the Oklahoma border, and east and west from outside Yates Center to the Missouri border. Depending on where the outage is, the drive alone can sometimes take an hour.
7:45 p.m. Arrival and line inspection
I often see people outside when their power is off, sitting on their porch or working in the yard. Sometimes I drive by several times. I often wonder what they are thinking when they see me driving by multiple times. The first time you see me I’m most likely driving to the breaker. I need to go to the breaker to verify that it’s open. The second time you see me drive by I’m visually checking the line for what may have caused the outage. Checking the line can take some time. It’s one of the more time-consuming steps we take, but also one of the most important parts of restoring an outage. We can’t just simply flip a switch and restore the power. That can be dangerous for many reasons. The outage could be a line down in someone’s yard, or it could have been caused by equipment failure. Re-energizing the line under those two examples would be very dangerous to the public and could cause more damage and just extend the outage longer. A few examples of things I’m looking for are fallen trees, tree limbs, old line repairs that have failed, car accidents, lightning, animals and equipment failure.
Another factor that can add time to inspecting the line is terrain. We try to put poles along the road, but that can’t always be accomplished. Electric co-op lines go where they are needed, and that might be in extremely remote places. If it’s not along the road, the line must be checked on foot. If it’s dark that can make this job even more difficult and time consuming regardless of where it’s located.
8:30 p.m. Outage cause located, but first safety.
Once we find the cause of the outage, there are safety steps that must be taken before we can start the work. These safety procedures add time, but they are vital. The most important thing we have to do is isolate and ground the line. This is an important step for many reasons. One reason is to protect from back feed. Lineworkers always try to be aware of their surroundings. An important thing to listen for and to be aware of are home generators. The transformer on your pole that drops the voltage down can also work in reverse. Your home generator, if installed wrong, could back feed through your transformer and put primary voltage back on the line. To protect lineworkers, we install grounds as close to the work location as we can on both sides of the work. These grounds connect the neutral wire to all primary wires making them all the same ‘grounded potential’ and safe to work on. The final safety step is the briefing. During the safety briefing, the job plan is discussed and explained and hazards are identified.
9 p.m. All safety procedures are in place. We can begin the work.
Let’s say for this outage it was a tree. A 50-foot-tall oak tree fell through the line. It’s off the road, but we got lucky—it broke a crossarm, but the pole is good. The wire isn’t broken either but is currently under the oak tree. We’ve got to chop the tree and free the wire. This will take some time. Anyone who has cut up a downed tree will understand the danger. You have to be careful and pay attention to the tree and how it’s sitting on the ground. Downed trees can shift, and roll while being cut. And here you also have power lines under tension, pinned down by the tree adding an extra layer of danger. Special care and awareness must be used to remove this tree. Sometimes the power lines must be tied down, so that they can be let up in a more controlled manner once the tree is cut. While we work to clear the tree from the line, new material is on the way. We are going to need a crossarm, crossarm braces, new insulators, bolts and ties to tie in the wire.
10:30 p.m. The tree has been cleared and the material has arrived.
As I mentioned, the pole is off the road, so that means we can’t get a bucket truck to it. We will have to climb the pole. One of our lineworkers will put on his belt and hooks and climb to the top of the pole. One thing he will take with him is a handline. It’s a rope in a pulley that’s long enough to go from the top of the pole to the ground in a loop. This will be used to lift material and other objects to the lineworker that were too heavy or awkward to take up in his belt. Once he gets to the top of the pole, he will get to work. He’ll start by removing all the broken material. He’ll also inspect the top of the pole for damage we couldn’t see from the ground. Once he has it cleaned up, we will start sending up material on the handline. He should have taken the crossarm bolt with him when he climbed and installed that in the pole. The lineworker on the ground should have already put everything on the crossarm. Next, the lineworker on the ground will tie the crossarm onto the handline in a way that will allow the lineworker on the pole to just guide the arm onto the bolt as it’s being lifted up. Once the new crossarm is on the pole and all the bolts are tightened the wire will be lifted up, also with the handline, and placed on the arm. The wire ties will be sent up, again on the handline, and the lineworker will tie in the wire. After completing all the work in the air, the lineworker will send down the handline and climb down. We’ll all carry the tools that we used back to the truck and get them packed away. Lastly, we will remove our grounds.
11:45 p.m. Repairs complete
Now if you still happen to be on your porch, you will see me drive by a third time. This is good news because you are about to get your power restored. I’m heading for the breaker. Since I’m dealing with an outage in one particular place, I will go ahead and close it in and restore your power, notifying dispatch afterward. Had this been part of a larger outage, I would have called dispatch to get clearance to re-energize, because there might have been others working on another outage on the same line. In some cases, dispatch can even close in breakers remotely using our SCADA system.
12:05 a.m. Power restored. Outage over
Keep in mind this is just one scenario; not every outage is the same. Each outage varies in time for restoration. This example outage took around five and a half hours to restore. If the tree had broken a pole, it would have been even longer.