Transcript Power In America

Electrical Power
Distribution in America
49.9 % Coal
20.3% Natural Gas
6% Hydro Electric
20.4% Nuclear
3.4% Other
http://www.eia.doe.gov/emeu/mer/pdf/pages/sec7_4.pdf
Power Plant Generation

Turbines

Output 11KV to 22KV
Generated Power Distribution

Power Plant Turbine
Output Voltage
Transformed to
Higher Voltage


155,000 volts to
765,000 Volts
Higher voltage, lower
current = less line
loss
End User


High Distribution Voltage
Transformed Down
Common Commercial
Substation Voltage


12,000 Volts
Residential

7,200 Volts
Commercial End User

Transformed From 12,000 Volts, 3 Phase


480/277 Volts Three Phase
208/120 Volts Three Phase
480/277 Volt Rules of Thumb

Phase Conductors Marked




Brown, Orange, Yellow
Neutral – White
Ground – Green
Voltage reading between
phases (Brown to Orange, Yellow to
Orange, or Yellow to Brown)


480 volts
Voltage reading phase to
neutral (Brown to White, Orange to
White, or Yellow to White)

277 volts
208/120 Volt Rules of Thumb

Phase Conductors Marked




Black, Red, Blue
White - Neutral
Green – Ground
Voltage Reading Between
Phases (Black to Red, or Red to Blue
or Black to Blue)


208 Volts
Voltage Reading Phase to
Neutral (Black to White, Red to White,
Blue to White)

120 Volts
Residential End User

Transformed From 7,200 Volts

240/120 Volts Single Phase
Residential Single Phase

3 Wire’s coming into your
home



Voltage between the two hot
wires (Black to Red)


Black and Red Wires are Hot
1 White is Neutral
240 volts
Voltage between hot and
neutral (Either the Black to White or the
Red to White)

120 volts