You wake up early in the morning and flip on the light switch as you get out of bed. You bump into walls like a pinball walking down the hall to the kitchen to turn on the coffee pot. With one eye open and the other shut, you make it back to the bathroom and start a hot shower before work. Sound familiar?
Have you ever got out of bed thinking about how the light comes on? How does the shower get hot? Electric is like the air we breathe; we don’t think about it until we don't have it. We only realize how important power really is during a power failure, sitting in a dark room, instinctively hitting the useless light switch.
Power comes from the power plant to your house through a system we’ve come to know as “The Grid." The power plant consists of a spinning electrical generator. The spin is created by a water wheel in a dam, diesel engine, gas turbine, but most of the time it is a steam turbine created by burning coal, oil, or natural gas. No matter what is used to spin the generator what is produced is called 3-phase AC power. Three phase power is simply three single phases synchronized and offset by 120 degrees. Think of a cooling fan with three blades.
The wires from the generator then enter a transmission substation at the power plant. The substation uses large transformers to convert the voltage, approximately 155,000 to 765,000 volts, to travel long distances, 300 miles, on the transmission grid. In order to distribute the power to your home the voltage must be stepped down from the 155,000 to 765,000 volts to a more usable voltage, typically less than 10,000 volts per one phase. This reduction or stepping down of the higher voltage takes place at local distribution substations you see around town. Ocala has over 20 distribution substations to ensure the reliability of your service.
Residential customers typically only need a single phase for their electrical needs. There is a transformer (the large drum on the pole) which reduces the 7,200 volts down to the 120/240 volts which make up your household electrical services. The 120/240 volts then enters your home through a watt-hour meter, which allows the electric company to measure your usage.
The circuit breakers and fuses inside your home are safety devices. All of the outlets and lights within your home have different wires connected separately to a circuit breaker or fuse. When the circuit breaker is on, power flows through the wire in the wall and to the outlet.
That is a lot of equipment and downsizing of electricity to get power from the power plant to the lights in your bedroom. Now as you go to flip that switch you will have a better understanding of the incredible process that takes place before your lights come on.