Electricity Transmission and Distribution

Transformer A device that transfers electricity from one circuit to another

Step-up Transformer A type of transformer that increase the voltage of electricity as it passes through

Step Down Transformer A type of transformer that decreases the voltage of electricity as it passes through

Transmission Voltages from Generator to Household 1. Electricity is generated at 12,500-25,000 volts 2. Goes through step up transformer – upped to 138, ,000 volts 3. Carried through transmission lines

Transmission Voltages from Generator to Household 4.Substations – use step down transformers to lower voltage to desired level depending on the usage. 5.Distribution lines serving houses are usually 12,000 volts 6.Transformer on poles beside a house reduce the voltage down to 120 volts

Transmission Voltages from Generator to Household 7. A typical house will have 2 legs of 120 volts for a total voltage in the house of 240

Different Application use different voltages Pubic Transportation (subways, trolley cars) use 600 volts Industrial Plants may use voltage as high as 34,000 (they would have step down transformers inside the plant to further reduce the voltage)

Review Questions Define Transformer Step Up Transformer Step Down Transformer Distribution Line Substation Transmission line

To increase voltage from 12,500 to 138,000 volts you would need a ____________. To decrease voltage from 7,500 to 120, you would need a ____________. The power lines that go cross country and are usually very high off of the ground are referred to as ___________________

The type of line that your house is connected to is a _______________.