Download Electricity - Glen Rose FFA

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 138,000-765,000 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 _______________.