Module 1: Principles of Electricity PDF

Bulacan State University College of Architectecture and Fine Arts BU 313 Utilities 2: Electrical and Mechanical Systems Module 1: PRINCIPLES OF ELECTRICITY A) History Date Events 600 BC It was discovere...

Bulacan State University College of Architectecture and Fine Arts BU 313 Utilities 2: Electrical and Mechanical Systems Module 1: PRINCIPLES OF ELECTRICITY A) History Date Events 600 BC It was discovered that by rubbing amber it will became charged. William Gilbert described the electrification of many substances. Gilbert is 1600 AD called father of modern electricity. Otto von Guericke invented a crude machine for producing static 1660 AD electricity. Stephen Gray distinguished between conductors and non conductors. 1729 AD D.U. du Fay recognized two kinds of electricity. “Vitreous and resinous” Benjamin Franklin and Ebenezer Kinnersley named these two kinds of 1752 AD electricity "positive" and " negative". Pieter van Musschenbroek invented the Leyden jar which stored static 1745 AD electricity. William Watson discharged a Leyden jar through a circuit, and comprehension of the current and circuit started a new field of 1747 AD experimentation. The invention of the battery opened an interest in currents. Physician and scientist. Continuous current from batteries was the basis for the discovery of G.S. 1827 AD Ohm's law J.P. Joule's law of electrical heating. Ohm's law together with G. R. 1841 AD Kirhoff's rules, which came later, is the basic means of making circuit calculations. Han Christian Oersted discovered that a magnetic field surrounds a wire 1819 AD carrying current. Danish scientist. Andre-Marie Ampere had established several electromagnetic laws. D.F. 1821 AD Argo invented the electromagnet. Michael Faraday invented the electromagnet Michael Faraday and Joseph Henry invented the electric generator. 1831 AD Hippolyte Pixii constructed a hand driven model of a generator. 1858 AD First steam driven generator was put into service. C.F. Brush installed the first arc lights in Wanamakers store in 1878 AD Philadelphia. U.S.A. Joseph W. Swan invented the carbon filament lamp. 1879 AD Thomas Alva Edison advocated direct Current (DC) The first central electric-light power plant in the world, "Pearl Street Plant" 1882 AD was completed by Thomas Edison in New York City, USA. C.A. Parsons introduced the steam turbine to drive an alternator to 1888 AD produce alternating current (AC). Nikola Tesla designed the first hydroelectric power station in the world at 1893 AD Niagara Falls, producing alternating current. In the late 19th century the major fuel used for the production of 1900 AD electricity was coal. By 1950 clean-burning fuels of natural gas and oil, a product of petroleum, had taken the lead for producing electricity. 1950 AD Since 1950, nuclear power has been playing a role in producing electricity. Source: Electrical System for Architects by Aly S. Dadras History of Industrial revolution and the Mechanical / Electrical technology: The Industrial revolution is a revolution from handmade to production assembly. It is an increase in production brought about by the use of machines and characterized by the use of new technology.  Industrial revolution started from 18th century to the 19th century. From 1750 – 1850.  Started in Europe particularly in Britain on the British textile industry.  John Kay – 18th.century inventor who invented the spinning frame or spinning jenny to replace spinning wheel.  Thomas Newcomen – 1712 invented the atmospheric engine to which helps to pump water from earth.  James Watt – Scottish inventor improved the Newcomen engine with his Watt steam engine in 1776.  Richard Trevithick – British inventor most significant for his development of first steam engine locomotive to which in 1804 took its first journey. Though during the same era, not only in Europe were industrial revolution took place, China was even earlier with the invent of paper, fire cracker / first fire arms and India with the mathematical symbols and equations, still Europe were more superior in terms of Science and Technology. Advantages of European and why it has the cradle of Industrial revolution:  Great minds and inventors.  Exposure to knowledge more superior than any nations during those time.  Rich in Coal to which replace wood as a source of new energy.  Steam as by product of the new source of energy. Disadvantages:  High wages that actually give way to more human less activity.  Dirty and polluted community  Violence  Black death and Plague Industrial revolution can be divided into 2 parts. 18th century was the First Industrial Revolution that took place in Europe and the Second Industrial Revolution in the 19th century that took place to the new found land, United State of America. The second industrial revolution may be tracked through the works and perseverance of the great moguls and pillars that built the America today. Their records may have not been that nice and they built their empires to the back of inhumane labor practices, still they have been the prime movers and players of the second industrial revolution.  Andrew Carnegie  John Rockefeller  John Pierpont Morgan (J.P.Morgan) Chicago World Fair – The Columbian Exposition 1893 – The White City - The World’s First glimpse of the future of lighting and the source of new power. It was called “The White City” because it glimmers from afar, never been seen glowing lights that makes everything white in the middle of the night. - Known as the final battle of AC and DC of Edison and Tesla.  Thomas Edison  Nikola Tesla B) Electricity  Form of energy generated by friction, induction or chemical change, having magnetic or radiant effect  Modern electron theory states that “ the fundamental nature of all matter is electrical”.  Electrons in motion.  Is a property of the basic particle of matter  Proton  Electron  Neutron  William Gilbert is the Father of Electricity describes “electrification of many matters”. C) Electricity found in Nature  Lightning  Galvanic cells (pipe corrosion)  Static Discharge (electric charge at rest)  Electromagnetic radiation from the sun D) Production of Electricity  Turbines and generators are basic components that generates electricity.  Turbine is a rotary engine that changes the force of water, fuel and wind into mechanical energy capable of rotating that shaft which is connected to a generator.  A generator is a machine used to change the mechanical energy into electrical energy.  Turbines that produces mechanical energy: a) Water-driven turbines – run through water force b) Steam-driven turbines –heat energy into mechanical energy through steam c) Nuclear-reactor turbines Other electrical producing equipment: a) Internal combustion engines (ICE) – identical to engine of automobile which the shaft rotates to produce electricity. Invented by Rudolf Diesel which diesel engine was named after him.  b) Wind turbine - converts the power of wind into electrical power. It requires 10 mile per hour wind to operate properly. c) Solar Photovoltaic cells - sun’s power to produce electricity by means of silicon wafer with small amount of arsenic. The wafer is treated with boron gas. The contact between wafer and modified gas zone produces voltage which flows by the action of sunlight. These are connected to batteries to store the energy. E) Electric Current a. Ions b. Volt/Voltage c. Ampere d. Watt e. Resistance (in ohms f. Impedance (in ohms) g. Electric Current can be classified as : F) Electric Energy i. Direct Current (DC)  DC flows in one direction , from negative to positive  DC is produced by a DC generator and is utilized for special equipment requiring exact revolutions per minute (RPM) for proper operation.  Small quantities are produced by batteries or by rectifiers.  Usually used for emergency lighting, communications, signals and control equipment etc. such as elevators, rapid transit propulsion system, vehicles, electro chemical processing, printing press drives, electro plating, motors and compressors in HVAC/  Frequency 0 hertz , voltage is constant  Proponent of DC Electricity is Thomas Edison  Watts ii. Alternating Current (AC)  Reverses its direction of flow  Found in transmission lines   Frequency in cycles per second (hertz)  AC is produced by an Ac generator which commonly referred to as an alternator.  Advocator of AC Electricity is George Westinghouse  Alternating current reverses its polarity and reverses its direction of flow on each alternation  Increase voltage has low power loss, lower voltage drop, and more economical to construct  Watts  Power factor (simply pf) G) OHM’s Law  George Simon Ohm – German Scientist in 1926 who discovered the relationship between the current, voltage and resistance  Ohm’s Law States that “ when a current (I) flows through a circuit with given resistance (R) , is directly proportional to voltage (V)”. Power (unit Watt) Power is the time rate for doing work or the rate at which energy is used. In English system the units of power are: Watt  The unit of power is watt, named after James Watt.  Watt is when 1 ampere is flowing under the force of 1 volt and expressed in watts (W).  For electrical devices such as heater, toaster, incandescent lights etc.  For power equipment for calculations of power (W) DC differs from AC: Power Factor  Power factor angles of any equipment vary from 0° to 90° lagging or leading, causing reduction in percentage of power used.  The equipment with high PF is more efficient and more costly.  The equipment with low PF is less efficient and less costly. Measurement of Electrical Energy  The amount of electrical energy used is proportional to the power (W) used in building and the duration of time consumed. Electrical energy used = power (W) x time (h)  Unit of energy is watt-hour (Wh) or kilowatt-hour(kWh) H) Batteries  Peter von Musschenbroek in 1774 invented the Leyden Jar, which stored static electricity.  William Watson discharged a Leyden Jar through a circuit, and the comprehension of the current and circuit started a new experimentation.  When two different metals such a zinc and copper are placed in a container with salt, water or diluted sulfuric acid, a current is caused to flow between the electrodes.  There are four types of batteries today: a) Dry-cell batteries – are group of dry cell batteries connected to act as source.  “A” batteries provides 1.5 to 12 volts  “B” batteries provides 6 to 12 volts  “C” batteries provides 1.5 volts  b) Storage Batteries (wet-cell) – each cell contains a number of alternately positive and negative plates separated by liquid electrolyte of sulfuric acid solution. c) Edison cell batteries (wet-cell) – has nickel oxide positive plate and and iron negative plate suspended in a solution of potassium and lithium hydroxides. It has longer effective life and the capacity to withstand abuse. It is used mostly in railroads. d) Solar Batteries – used to store the electromagnetic radiation from solar cell. I) Series and Parallel Circuit Series Circuit – a single path exist to current flow Vtotal = V1 + V2 + V3 Rtotal = R1 + R2 + R3 Parallel Circuit – multiple connections where loads are placed with the same voltage thus create as separate circuit. Left: Series / Right: Parallel Arrows indicate direction of current. The red bars represent the voltage as it drops in the series circuit. The red bars in the parallel circuit do not drop because the voltage across each element in a parallel circuit is the same. J) Volt Transformation  Transformer is a static device, consisting essentially of two unconnected, insulated coils, called primary terminal and secondary terminal, wound around a hollow core of laminated iron.  Volt-ampere always enters into primary terminal and exits from secondary terminal.  Transformers are used only for alternating current or AC.  A transformer is a device which transforms or inducts AC of one voltage to AC of another voltage.  When a transformer increases voltage it is called step-up transformer.  When a transformer decreases the voltage it is called a step-down transformer.  The voltage appearing on each terminal has a direct proportion to the number of windings turns.  Classified as indoor or outdoor type.  Transformer are specified as follows: K) Voltage, Power and Energy