Electricity is generated in what is called a power plant. Power is generated by many forms. Power can be generated by steam, coal, oil, natural gas, Hydroelectric, Hydrogen, Solar and Nuclear. Electricity is harvested by using the power to turn a generator creating electricity. Power cannot be created nor destroyed; it can only change forms. When the power created by one of these is used, the energy is transformed into electricity.

After the power plant has turned their source into electricity it is sent to what is called the power grid. The first leg of the power grid is the transmission lines, these are large power lines that stretch hundreds of thousands of miles. Typically carrying 345,000 volts, these lines make their way to what is called a substation.

The Substation is the first stop after the power plant. The substation performs many different functions such as power line monitoring, power line safety and step down power. Step down power is where the transmission voltage is stepped down to what is called primary voltage. Primary voltages range from 4 Kilovolts (kV) to 35 Kilovolts (kV). This Primary Voltage is then sent to Distribution power lines.

If Transmission power lines are the interstate of electricity delivery, distribution power lines are the highway. These power lines carry electricity in what are called phases, A phase, B phase and C Phase. These phases are sent through either overhead, underground or both styles of power lines.

Overhead power lines are what commonly comes to mind when we think about power lines. They are the wires running across the top of a power pole all around town.

Sometimes you might see overhead power lines just stop, then you will see them change over to a different looking wire that runs down the pole in a conduit and underground. This is just a modern way of running power lines. With overhead the power lines are exposed to many hazards such as fallen trees, strong winds, vehicular accidents, animals and just old age. Underground power lines offer protection from many of these factors because they are underground typically 6 feet or more. The down sides to underground power lines is that they are very expensive to install, require earth moving equipment to dig a 6 foot or deep trench, and can easily be unearthed if anyone is digging without calling 811 to have the area marked.

No matter underground or overhead their main objective is to feed a transformer.

Everyone has seen a transformer at one point in their lives. The large battery looking thing with two robotic rabbit ears or those big metal green square boxes in people’s yards. These step down transformers commonly known as transformers are what transforms the primary voltage to an end user appropriate voltage called secondary voltage or “secondary” for short.

Secondary voltage is what feeds the house or building electricity. Your common voltages on secondary are:

• 120 volts single phase

• 120/240 (most common)

• 120/208 (most common for apartment buildings)

• 277/480 (most common for commercial/industrial buildings)

The secondary voltage has already been determined by the electrical engineer who designed the structure and the utility engineer. Once the power has been stepped down to secondary it then travels to the structure on what is called the “service feed” or just service. This can be overhead or underground as well. The service is brought to the structure and feeds the structure by either a weather head (overhead) or an underground service feed.

• Weather head is where overhead service connects to the structure. The secondary service from the utility is terminated to the structure's main entry to feed the structure. When it comes to overhead services the weather head can be a meter technicians' best friend. With your eyes you can follow the line to the weather head, and you will find your electric meter typically.

• Underground service is underground so not as obvious as to where the meter is located. You will learn more on how to locate meters with underground service during your field training.

• From the service, before the structure is fed electricity, an electric meter is installed to monitor the usage.