MAGM 225 Residential and Farmstead Electrical Wiring and Principles

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MAGM 225 Residential and Farmstead Electrical
Wiring and Principles

• Mr. Amador

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Introduction

• Define electricity?
• Webster- A source of energy from particles of
  matter.
• Dictionary.com -The science dealing with electric
  charges and currents.
• The flow of electrons through a conductor.

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The atom and their charges

• Parts of the atom
• Proton Positively charged
• Neutron - Neutral
• Electron Negatively charged and orbit around
  the nucleus
• Electrons in the outer orbit are known as valence
  electrons and they can number from 1-8 electrons

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The Basic Structure of an Atom
Elements with less than 4 Electrons in their
outer rings make good conductors
Because the Electrons are easily dislodged from
their orbit and pushed to the atom next to them.
(Electron flow)
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The Basic Structure of an Atom
Elements with More than 4 Electrons in their
outer rings make good insulators
Because the Electrons remain in the outer rings
when electromotive force (Voltage) is present.
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How dose electricity flow? What causes electrons
to move from atom to atom?
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Voltage
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Voltage is the abundance of electrons on one side
of a conductor as compared to the other side.
This could also be described as the potential for
electron flow or potential difference.
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How dose electricity flow? What causes electrons
to move from atom to atom?
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Voltage
(Pressure)
(Electromotive Force)
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Voltage Pushes the electrons
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How dose electricity flow? What causes electrons
to move from atom to atom?
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Voltage
(Pressure)
(Electromotive Force)
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Voltage Pushes the electrons
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How do we create this flow?
Magnetism Chemical Pressure Light Friction Heat
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How Do We Measure This Flow?
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Voltage

• Electrical Pressure, potential, or potential
  difference
• Unit is Voltage V or EMF
• Meter symbols
• VAC - V
• VDC - V

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Resistance

• Opposition to current flow
• Unit - Ohm
• Symbol - Omega
• All components and wires have resistance.

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Current

• Flow of Electricity
• Unit Ampere
• 1 Ampere
• 6,250,000,000,000,000,000,000 electrons/second
• Symbol - A or I

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Wattage

• Watt is a unit of electrical work.
• Watts Volts X Amps
• Amps Watts / Volts
• Volts Watts/ Amps

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Sample Problem

• How many strands of Christmas lights can we put
  on a 20 amp circuit if each strand holds 50 4
  watt bulbs

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Answer

• Watts Volts x Amps
• 50 bulbs _at_ 4 watts each 200 Watts
• 200 Watts 120 Volts x Amps
• 200 watts / 120 Volts 1.66 amps / Strand
• 20 Amps / 1.6 amps 12.5 strands

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Problem 2

• We have 60 light bulbs in our house. They are
  all 60 watts each. How much does it cost to run
  the lights 8 hours a day for a year?

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Answer

• 60 bulbs _at_ 60 watts 3600 watts
• 3600 watts x 8 hours x 365 days / 1000
• 10512 Kilo Watt Hours
• 10512 Kilo Watt Hours _at_ .09/ KWH
• 946 / year

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Question 3

• How much do we save if we change all the bulbs to
  14 watt florescent bulbs.

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Answer

• 60 bulbs _at_ 14 watts watts
• 840 watts x 8 hours x 365 days / 1000
• 2453 Kilo Watt Hours
• 2453 Kilo Watt Hours _at_ .09/ KWH
• 220 / year
• 946 220 726 / year savings