Sending power to your home is a lot like driving to a neighboring state. You wouldn’t consider taking a two-lane secondary road to travel to a city hundreds of miles away, would you? Of course not: You would find the nearest interstate so you could drive faster and arrive at your destination in less time.
Just like you, your electricity has an interstate that allows it to travel long distances, and a secondary system that winds through back roads and neighborhoods to direct it to its final destination, your home.
Transmission lines that deliver power from a power plant to substations are the fast-moving interstate highways of the electric industry. These lines carry from 44,000 to 100,000 volts of electricity into the local distribution substation. They are located on structures ranging from large metal towers more than 100 feet tall to a single pole standing 70 to 90 feet in the air.
And just like a car leaving the interstate, the electricity leaving the substation has to slow down when it enters the distribution lines serving YEC’s service area. Transformers in the substation provide the braking system for lowering the voltage of the electricity so it can continue safely along its journey.
So, how does it work? Higher-voltage electricity passes through a system of coiled wires located in the substation transformer. The electricity enters a primary side of the transformer, which has metal coil windings surrounding that side of the transformer, and then passes to a secondary side, which has fewer coil windings. Traveling through the reduced number of windings lowers the voltage as it leaves the secondary side and continues the journey along the distribution lines.
The electricity moving along YEC’s distribution lines is cruising between 7,200 to 14,400 volts or 12,470 and 24,900 volts depending on whether or not they are traveling along a single-phase or a three-phase line. Consider these lines the secondary roads of the electric system. They make the journey through the local co-op’s service area.
Distribution lines carry the electricity shorter distances than transmission lines. They transport electricity to the businesses, schools and homes served by your co-op. These are the lines you see YEC’s crews repairing after a storm.
Your electricity has one more stop before making its way into your home. Just as you slow down to pull into your final destination, the voltage is lowered one more time. It takes a turn off the distribution line and into another transformer that’s located outside of your home. This transformer may be a canister hanging on a pole or a box in your yard if you have underground electric service. Transformers are protected by fuses that will disconnect them from the electric line if there is a fault caused by current surges or overloads.
After the current leaves the transformer, it makes its way through a service line, into the meter base and to its final stop on the electric highway—your home, where it powers the appliances and electronics of our modern world.
Off like a shot
It sounds like a shotgun going off or, as many people think, “a transformer blowing,” but the blast you sometimes hear just before an outage is usually a protective device for electric circuits called a fuse. A fuse located inside the barrel-shaped enclosure is what normally blows. For example, a tree limb falls on a line; the device does its job by opening the circuit to limit the outage. Fuses are also installed atop co-op transformers to reduce the likelihood of real (and costly) transformer explosions.
How YEC restores power
South Lancaster substation, transmission lines under construction