Transcript Agricultural Electricity

Agricultural Electricity
What is Electricity?
• Easier to describe what it does than
what it is!
• The flow/movement of electrons through
a material.
Direct Current (DC)
• Flow of electrons in only one direction.
• Produced by:
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DC Generators
Batteries
Solar (PV) Cells
Wind Turbines
Alternating Current (AC)
• Flow of electrons in one direction and
then the other.
• Produced by AC generators.
• Supplied by Modern Power Suppliers.
How do they flow?
• Conductors
• Materials that allow electrons to readily
move from one atom to another.
• Most metals are good conductors. (silver,
copper, gold, aluminum)
• What about water?
• Distilled water?
Copper vs. Aluminum
Copper
-Used Primarily on
the customer side
of the meter.
-A better conductor
than aluminum.
-More expensive.
Aluminum
-Used primarily on
the utility side of
the meter.
-Not as good a
conductor as copper.
-Less expensive.
-Lighter.
Insulators
• Materials that do not allow their
electrons to readily move from atom to
atom.
• Rubber, plastic, glass, porcelain,
ceramics.
Voltage (Volts)
• The pressure/force pushing the
electrons through the material.
• Similar to water pressure in a water
piping system.
• Supplied by the generator.
• Symbol= E or V
Kilovolt (kV)
• 1000 volts
• Used to define the voltages of
transmission lines and higher voltage
distribution lines.
• Examples:
• 345 kV line=345,000 volts
• 12.5 kV line=12,500 volts
Current (Amps)
• The rate of flow of the electrons through the
material.
• Similar to the flow rate (gallons/minute) in a
water pipe.
• One Ampere=6,280,000,000,000,000,000
electrons per second
• Byproducts
• Heat
• Magnetic Fields
•Symbol=I or A
Resistance (Ohms)
• Measure of a materials
impedance/resistance to the flow of
electricity through it.
• Similar to the friction/head loss in a
water piping system.
• Symbol= omega
Resistance Creates Voltage
Drop
• Voltage drops on a circuit the farther
you get from the source.
• Low voltage can cause:
• Dim lights
• Hot motors
• Reduced motor life
Real Power (Wattage..Watts)
• A measure of the power used by an
appliance.
• “The rate or ability to do work”
• Symbol: W
Kilowatts
• 1000 Watts
• Most power suppliers use kilowatts to
quantify how much power
commercial/industrial customers use for
billing purposes.
• Symbol=kW
Megawatts
• 1,000,000 watts
• Commonly used by electrial people to
measure the power a generator is
capable of producing or the power
requirements of large customers or
cities.
• Symbol=MW
Ohm’s Law
• The basic physical law describing how
electricity acts.
• Volts=Amps X Ohms
• Helps us figure out “How big should the
wires be?”
Why can’t I run my coffee
pot, toaster, blender &
microwave without the
breaker tripping?
• How many amps does a circuit with a
1000 watt coffee maker, a 500 watt
toaster, a 200 watt blender and a 700
watt microwave draw when all operate?
Use Watt’s Law
• 700+1000+500+200=2400 Watts
• Watts=Volts X Amps
• 2400 Watts divided by 120 volts=20
amps
Practice
• On a 120 volt system how many amps
will a 800 watt microwave, 1000 watt
coffee maker, a 500 watt toaster and a
200 watt radio.
• Watts= volts x amps
Long-Nose Pliers
Diagonal-Cutting Pliers
Crimper
Multipurpose Tool
Wire Strippers
Cable Ripper
Lineman’s pliers
Automatic wire strippers
MultiMeter
Amp Meter