MODULE-1_ABUTLN2 (1).pdf

#1 COLLEGE OF ARCHITECTURE B.S. ARCHITECTURE FLEX Course Material To introduce Electricity and Electrical Systems. To identify the important terms in Electrical Systems. To identify the different units of m...

#1 COLLEGE OF ARCHITECTURE B.S. ARCHITECTURE FLEX Course Material To introduce Electricity and Electrical Systems. To identify the important terms in Electrical Systems. To identify the different units of measurements in ABUTLI2S Electrical Systems. BUILDING UTILITIES 2: ELECTRICAL, ELECTRONICS AND MECHANICAL SYSTEMS ELECTRICITY AND ITS SOURCES Cluster Chair AR. KAOLYNE GRACE C. HILARIO Cluster Heads AR. EMMARIE ROSE V. CRUZ & AR. ANNIE C. PUGEDA Cluster Members AR. JOFFREY STEPHEN C. CHUNG AR. ALPHER E. DE VERA AR. HARVARD LOUIE D. HERNANI AR. FERNANDO RAPHAEL F. LOPEZ AR. ANTHONY M. PLA  #1 Definition of Electricity. Types of Electric Currents. Introduction to Types of Electrical Circuits. Electricity and Sources of Electricity. Electrical Systems Electricity Phenomenon; manifestation Principally made up of atoms – electron, proton, neutron Definition of Electricity A form of energy generated by friction, induction, or chemical change having magnetic, chemical, and radiant effect. The motion of free electrons through a solid conductor. Notes William Gilbert – English Physicist; considered “Father of Electricity”. Instantaneous – electric current travels at Electric current – flow in an the speed of light. electric circuit. Two types: General classes of electricity: Direct current (DC) Dynamic Electricity (electro dynamic) Alternating current (AC) – flows through a substance in the Electric circuit – path for electric form of an electric current. current. Static Electricity (electrostatic) 3 Types of Electric Current Direct Current (DC) Alternating Current (AC) Direct Current (DC) A current that flows at a constant time rate and in the same direction. Flows in one direction (- to +). Uniform in strength. Best example – Battery / dry cell; batteries Direct current is used in any electronic have positive (+) and negative (-) device with a battery for a power source. It is also used to charge terminals. If you take a wire and connect batteries, so rechargeable devices like the positive and negative terminals on a laptops and cell phones come with an AC adapter that converts alternating battery, the electrons in the wires will current to direct current. begin to flow to produce a current. Two types: continuous and pulsating (fluctuating). 4 Types of Electric Current Direct Current (DC) Alternating Current (AC) Alternating Current (AC) Reverse in direction A current that is periodically varying in time rate and in direction. The current rises from zero to maximum, falls to aero, reverses its direction, and Almost every household and office are again returns to zero. A complete set of powered by AC because it loses less these changes is called a Cycle. power than DC and has fewer issues relating to converting high voltage to Frequency – cycles per second or Hertz. low voltage using transformers. In other words, transporting AC across long Frequency for lighting: 60 Hertz distances is comparatively easy. Frequency for motors: 25 Hertz We rely on AC to power electric motors and these are used in several household Phasing: Single Phase or 3-phase appliances, such as fridges, dishwashers and toasters. They are also used to power anything from the mains – such as the TV and any chargers you are using for your laptop, tablet or smartphone. 5 Comparison: DC vs. AC Direct Current (DC) Alternating Current (AC) Fixed polarity Reverses polarity Steady (continuous); vary in Varies between reversal magnitude (fluctuating) Steady value Stepped up or down Easier to measure: 1.5 volts Easier to amplify: 110 V+ 6 Electrical Circuit A complete conducting path carrying current from a source of electricity to and through some electrical device or load and back to the source. Types of Circuits Closed Circuit – complete, continuous path. Open Circuit – broken, incomplete, disconnected. *Note: in order for a circuit to work, it must be closed; thus open circuits are not functional. Series Circuit – a circuit in which the same current flows through all components of the If you have ever had trouble with circuit; the current has only one path to take. Christmas lights, you might have a little experience on series circuits; when one Parallel Circuit – a circuit in which the bulb is not functioning, the current components are arranged so that the current cannot flow, and the lights will not turn divides between them; each component is assured on. a charge. If a path breaks, the other paths will still Houses are built with parallel circuits; work because they are not reliant on each other. your entire house will not lose power if a light burns out. Short Circuit – a condition resulting from bridging Circuit breakers and fuse boxes are put any part of a circuit with a conductor of very low in place to cut off circuits as a safety resistance. The piece of circuit bypassed by the measure when a short circuit occurs. short circuit may cease to function and a large A short circuit is not just any electrical amount of current may begin flowing. This causes malfunction as some believe. wires to heat up and can potentially cause fire. 7 Types of Circuits – a simple illustration Closed Circuit Open Circuit Series Circuit Parallel Circuit Short Circuit 8 Sources of Electricity Battery Combination of two or more electric cells capable of storing and supplying direct current by electrochemical means. Battery 1. Primary Batteries – delivers electricity as soon as its parts are assembled, provided it is connected to a circuit; non-renewable. 2. Secondary / Storage Batteries – The first widely-used battery was the electricity from some external source Daniell Cell, produced in 1836. It must pass through before it can deliver powered the popular objects of the era: telegraphs and telephones. Which are an electric current; main use is for basically, old school text messages and emergency lighting; rechargeable. phone calls. So we’re still using batteries for the same things today. 9 Sources of Electricity Generator A machine which converts mechanical energy to electrical energy. 1. Alternating Current Generators or Alternators – converts mechanical energy to electrical energy in the form of alternating current. Most electrical energy utilized is in the form of alternating current or AC. Wind generators use blades to capture energy from the wind. An 2. Direct Current Generators – a rotating electromagnetic generator attached to the shaft then transfers the rotation to machine that supplies an electrical electricity. output with unidirectional voltage and current. Used for elevators, escalators, telecommunications, signal systems, and clock systems. 10 Dynamo Electric Machines An electrical generator that creates direct current using a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating- current alternator, and the rotary converter. Types Motors – a machine that converts electrical energy to mechanical energy Transformers – a machine for converting Electric motors are one of the most life- one voltage to another: from lower to changing inventions in human history as higher (step-up transformer) and from it has brought about the advancement of technology and engineering. Without higher to lower (step-down transformer). electricity and electric motors, our daily Rotary Converters – a machine for lives would not be what it is today. changing alternating current to direct High-rise condominium buildings are usually designed with a step-up current and vice versa. transformer. 11 Sources of Electricity – Electric Power Generation / Distribution 12  #2 Definition of important terms in Electrical Systems. Terms and Units Different units of measurement in Electrical of Measurement Systems. Ohm’s Law. in Electrical Systems Conductors Materials or substances which allow electricity to flow through them. Humans and animals are all conductors. This is the reason we get electric shocks! Have free electrons on its surface which Moreover, the human body is a good conductor; it provides a resistance-free allow current to pass through easily. path for the current to flow from wire to body. They allow the transmission of heat or Glass is the best insulator as it has the light from one source to another. highest resistivity. Copper, Brass, Steel, Gold, and Aluminum are good conductors of electricity. We use them in electric circuits and systems in the form of wires. Insulators Materials or substances which resist or don’t allow the current to flow through them. Do not have any free electrons. They give protection against heat and sound. Wood, cloth, glass, mica, quartz, plastic, and rubber are good examples of insulators. 14 Unit of Quantity Coulomb is the SI unit of electric charge, equal to the quantity of electricity conveyed in one second by a current of one ampere. Coulomb – a coulomb of electricity compromises approximately 6.25 x 1018 Ampere is named after Andre M. electrons. Ampere. Volt is named after Alessandro Volta, an Ampere (I) – an ampere of current Italian physicist who invented an electric battery. represents a rate of flow of one coulomb Watt is named after James Watt, a or 6.25 x 1018 electrons per second Scottish inventor. Ohm is named after Georg Simon Ohm, through a given cross section. a German physicist and mathematician. Ampacity – the current carrying capacity of a wire or cable expressed in Amperes. Unit of Electric Potential Volt (V) – electrical unit of voltage or potential difference between two points in an electric field. Unit of Electric Power Unit of Energy Watt (W) – electric power; rate of Watt-hours (Whr) – energy; doing electrical work. capacity for doing work. Unit of Resistance Ohm – resistance which allows one ampere of current to flow when one volt is impressed upon it. In DC circuit, ohm is called resistance (R). In AC circuit, ohm is called impedance (Z). 15 Ohm’s Law Relationship between Current, Voltage, and Resistance. The current which will flow in a DC circuit is directly proportional to the voltage, and inversely proportional to the resistance of the circuit Terms and Formula Terms: I = Current (Amperes) I= Intensity of electric current V = Voltage (Volts) R = Resistance (Ohms) W = Electric Power (Watts) The higher the voltage, the larger Formulas: the current. I = V/R The higher the resistance, the lower the current. V=IR R = V/I Other equations associated with Ohm’s Law: W = I2R or VI Whr = I2R t 16