MECHELEC-PART-1 (1).pdf

AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao ELECTRICAL SYSTEMS 1. GENERAL 1.1 Definition of Electricity Electricity is a form of energy generated by friction,...

AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao ELECTRICAL SYSTEMS 1. GENERAL 1.1 Definition of Electricity Electricity is a form of energy generated by friction, introduction, or chemical change, having magnetic chemical and radiant effects. It is the motion of free electrons through a solid conductor. An electric current travels at the speed of light and, therefore the rate of conduction of an electric current is considered instantaneous. Notes: 1. William Gilbert an English Physicist is considered as “Father of Electricity” for his studies on “Electric Attraction” and “The Electric Force”. 2. Electricity is a property of the primary particles of matter, which like an atom, consists of a negative charge, an electron; the positive charge is a proton; and the neuron, which is not electrically charged. 3. There are two (2) general classes of electricity: dynamic electricity (electrodynamic) which flows through a substance in the form of an electric current, and static electricity (electrostatic). 1.2 Sources of Electricity A. BATTERY A combination of two or more electric cells capable of storing and supplying direct current by electrochemical means. 1. Primary Batteries – delivers electricity as soon as its parts are assembled or assembled, provided it is connected to a circuit. https://www.theengineeringknowledge.com/wp-content/uploads/2021/08/Types-of-Battery.jpg 1|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. Secondary / Storage Batteries - electricity from some external source must be passed through it before it can deliver an electric current “changing the battery”. The main uses are: to supply emergency circuits for hallways, stairways, and exits and to energize police and fire alarm systems and certain types of signal systems. https://www.theengineeringknowledge.com/wp-content/uploads/2021/08/Secondary-Battery-Types.jpg B. GENERATOR A machine converts mechanical energy into electrical energy. 1. Alternating Current Generators or Alternators – The bulk of electrical energy utilized today is a form of alternating current, including energy for power and lighting. https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQb77FCS32__WRMzcx0pq4xOUqkVNEaJ3mBeaeVs2j6Viz1tvaf 2. Direct Current Generators – These furnish electric energy for elevators, intercommunicating telephone systems, control of signal systems, and clock system. Six Otis motor-generator sets and starter panels Image provided by: Chris Williams - U.S.A. 2|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 1.3. Other Dynamo Electric Machines A. MOTORS A machine that converts electrical energy into mechanical energy. https://t1.gstatic.com/images?q=tbn:ANd9GcQrrl2hTagR2iYPUh8pqzCe9YBH8vrwUeHMNANvT- 58Mb-RMG4o https://t1.gstatic.com/images?q=tbn:ANd9GcSG2y7XwGuHk- _COjYPmBxS8nY3mMObdZ1ITLExWFI_zjEZ4GFg B. TRANSFORMERS For converting one voltage to another from lower to higher (step-up transformer) from higher to lower (step-down transformer). The two types of transformers are the a) Oil –insulated Transformers and the b) Dry type transformers. 1. Outdoor Transformers  H-frame transformer bank – capacity as high as 1,000 KVa https://img.directindustry.com/images_di/photo-mg/50469-16511801.webp  Cluster mounted on a single pole – 225 KVa capacity https://upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Distribution_Voltage_regulators.JPG/1200px- Distribution_Voltage_regulators.JPG?20150308051238 3|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao  Pad-mounted https://www.flir.com/globalassets/industrial/instruments/global-utility-market/transformer.png 2. Indoor Transformers  Dry type https://www.elprocus.com/wp-content/uploads/dry-type-transformer.jpg  Askarel Insulated (“Askarel – synthetic non-flammable liquid) https://a-g-r.es/wp-content/uploads/2022/05/TRANSFORMADORESDEPCB.jpg  Oil–insulated installed into fire-rated transformers vault except when the capacity is not exceeding 112.5 KVa 4|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao Transforming Rating  Step-up transformer  Step-down transformer https://1.bp.blogspot.com/-MBiS73lh9uU/X98H1lZIuvI/AAAAAAAAWlY/VjFlbeQ-0-ANdtynKcegy3ETfw0HFB0_wCLcBGAsYHQ/w400-h363/step-up-and-step-down-transformer.JPG In short, a step-up transformer raises the voltage for transmission purposes. Step-down transformers convert high-voltage power to low-voltage. This makes the power level suitable to the requirements of each device connected to the power systems at household or business locations. C. ROTARY CONVERTERS For changing alternating current to direct current and vice versa. https://d3s1jw4anu9c80.cloudfront.net/hero/_AUTOx500_fit_center-center_95_none/Roto-con-Center-Pivot-Rotary-Phase-Converter.png 5|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 1.4. Types of Current A. DIRECT CURRENT A current which flows at a constant time rate and in the same direction. https://qph.cf2.quoracdn.net/main-qimg-45460a864369258012f4c372416e1664 https://www.electronics-notes.com/images/current-direct-dc-01.jpg B. ALTERNATING CURRENT A current which is periodically varying in time rate and direction. It rises from zero to maximum falls to aero, reverses its direction, and again returns to zero. A complete set of these changes is called a cycle. The number of times the current goes through the above cycles per second is called the frequency of the alternating current and is referred to as the “hertz”. The frequency commonly used for lighting is 60 cycles per second and for motors 25 cycles per second. https://i0.wp.com/www.sunstyle.ee/wp-content/uploads/elementor/thumbs/ac-dc-voltage-time-graph-p4otv60k5z3x9sktk0i3f813g2ul6e1e1m38nqrmdc.jpg?w=640&ssl=1 6|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao Note: 1. The hertz is named after Heinrich Hertz. https://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/50Hz60Hz.svg/1200px-50Hz60Hz.svg.png 1.5. Units of Electricity A. UNIT OF QUANTITY  Coulomb - a coulomb of electricity comprises approximately 6.25 𝑥 1018 electrons.  Ampere - An ampere of current represents a rate of flow of one coulomb or 6.25 𝑥 1018 electrons/second through a given cross-section. o Ampacity is the current carrying capacity of a wire or cables expressed in Amperes, without undue heating Note: 1. The ampere is named after Andre M. Ampere. B. UNIT OF ELECTRIC POTENTIAL  Volt - is the electromotive force or potential difference between two points in an electric field which will move a charge of one coulomb between these points. Note: 1. Volt is named after Alessandro Volta, an Italian scientist who discovered that electrons flow when two different metals are connected by a wire and then dipped into a liquid that conducts or carries electrons. C. UNIT OF RESISTANCE  Ohm - The resistance which will allow one ampere of current to flow when one volt is impressed upon it.  In a direct current circuit (d-c) this unit is called resistance and is abbreviated R; in an alternating-current (a-c) circuit it is called impedance and is abbreviated Z. 7|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao D. UNIT OF ELECTRIC POWER  Electric power is the rate of doing electrical work and the unit is Watt or the Kilowatt. One kilowatt is equal to 1,000 watts. Note: 1. The Watt is named after James Watt, a Scottish inventor. E. UNIT OF ENERGY  Energy is the capacity for doing work. In electrical units, energy is expressed in Watt- Hours or Kilowatt-Hours. 1.6. Ohm’s Law The current, I, that flow in a d-c circuit is directly proportional to the voltage, V, and inversely proportional to the resistance, R, of the circuit. I (amp) = V (volts) / R (Ohms) Notes: 1. The higher the voltage, the larger the current. 2. The higher the resistance, the lower the current. Other equations associated with Ohm’s Law are: o W (Watts) = I2 R or VI o Whr= I2 R t o KWhr = I2 Rt/1000 1.7. Electric Load Control The effective utilization of available energy by reducing peak loads and lowering demand charge1. The control devices and systems are referred to as load shedding control peak demand control, peak load regulation, and power use control A. LOAD SCHEDULING AND DUTY-CYCLE CONTROL Installation’s electric loads are analyzed and scheduled to restrict demand by shifting large loads to off-peak hours and controlled to avoid coincident operations. B. DEMAND METERING ALARM In conjunction with a duty cycle controller, demand is continuously metered and an alarm is set on when a predetermined demand level is exceeded. _________________________________________________________________________________ 1 Demand Charge- the levying of charge for power (kW) in addition to the normal energy (kWh) charge. 8|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao C. AUTOMATIC INSTANTANEOUS DEMAND CONTROL Also called “rate control”, it is an automated version of the demand metering alarm system, where it automatically disconnects or reconnects loads as required. In setting up the system, the controllable or “sheddable” loads are separated from those which must remain uninterrupted or the “unsheddable” loads. The sheddable loads are: The unsheddable ones are:  Non-essential lighting  Essential lighting  Ventilation fans  Elevators  Space heating  Refrigeration’s  Comfort cooling  Compressors  Non-critical batch process  Process equipment equipment  Office machinery  Electric boilers  Sewage ejectors with appropriate level controls  Transfer pumps D. IDEAL CURVE CONTROL This controller operates by comparing the actual rate of energy usage to the ideal rate, the controls KW demand by controlling the total energy used within a metering material. E. FORECASTING SYSTEM These are computerized systems that continuously forecast the amount of energy remaining in the demand interval, then examine the status and priority of each of the connected loads and decide on the proper course of action. 1.8. Measuring Electric Consumption A. KWH METERS To measure energy, the time factor is introduced, such that, energy = power x time. A-C electric meters are small motors; whose speed is proportional to the power being used. The number of rotations is counted on the dials which are calibrated directly in kilowatt-hours. SCHEMATIC ARRANGEMENT of Wattmeter connections. Note that the current coil is in series with the circuit load, whereas the voltage loads are in parallel. 9|P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao https://images.unsplash.com/photo-1631739903646-23df4fbcace4?ixlib=rb- 4.0.3&ixid=M3wxMjA3fDB8MHxzZWFyY2h8NHx8ZWxlY3RyaWNpdHklMjBtZXRlcnxlbnwwfHwwfHx8MA%3D%3D&w=1000&q=80 TYPICAL INDUCTION –TYPE KWh Meter with Kw demand-dial. Decade dials register total Disc revolutions are proportional to the energy. Disc speed is proportional to power. 2. BUILDING ELECTRICAL SYSTEM 2.1 Branch Circuits A. CIRCUIT AND CIRCUIT ARRANGEMENTS An electrical circuit may be defined as a complete conducting path carrying a current form of a source of electricity to and through some electrical device or load and back to the source. The two-wire circuit, which is the most elementary of all wiring systems, consists of a live wire carrying the current to various power-consuming devices in the circuit and a neutral or grounded wire which is the return wire carrying the circuit back to the source of supply.  Open Circuit (Broken or Incomplete) – conducting elements are disconnected to prevent the flow of electricity.  Short Circuit – a condition resulting from bridging any part of a circuit with a conductor of very low resistance. 1. Series Circuit One of the components is connected in tandem. All separate loads of the circuit carry the same equal current and the total resistance, R, Is the sum of the resistances around the circuit. 10 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. Parallel Circuit (or Multiple Circuit) Is one in which the components or loads are so arranged that the current devices between them. Each current has a live wire connected to the current carrying wire of the circuit and also a neutral wire or grounded wire connected to the return wire of the circuit. With the system, the total current flow through the circuit is the sum of the current flowing through each outlet. B. CLASSIFICATIONS OF BRANCH CIRCUIT 1. General Purpose Branch Circuit Supplies outlets for lighting and appliance, including convenience receptacles https://4.bp.blogspot.com/-qRRvOMEP0vM/Ttz3FvTyz8I/AAAAAAAAAkE/DFsjEQO3nZI/s1600/apliance+and+general.JPG 2. Appliance Branch Circuit Supplies outlets intended for feeding appliances. Fixed lighting is not supplied. 11 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 3. Individual Branch Circuit Is designed to supply a single specific item, such as a motor load or a unit air- conditioner. Ching, F. (2008). The Visual Dictionary of Architecture. https://doi.org/10.5040/9781350096462 12 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao C. GENERAL CIRCUITING GUIDELINES The National Electrical Code requires the following rules and guidelines for the design of branch circuits for residences. 1. General: branch circuits shall be sufficient to supply a load of 30 watts per square meter in buildings excluding porches, garages, and basements. The requirement of 30 watts per square meter is up to 80 sqm for 20 amperes circuits (2,400 watts) or 60 sqm for 15 amperes circuits (1,800 watts). However, good practice suggests that the load should not exceed 1,600 watts for a 220-amperes circuit and 1,200 watts for a 115-ampere circuit. 2. All but the smallest installations, connect lighting, convenience receptacles, and appliances in a separate circuit. The code requires a minimum of 2-20 amperes of appliance between branch circuits to feed all small appliance outlets in the kitchen, pantry, dining, and family room. 3. Convenient receptacles in an area shall be wired to at least two different circuits so that in case of failure in any one of the circuits, the entire area will not be deprived of power. 4. General branch purpose circuits shall be rated at a minimum of 20 amperes wired with No. 12 AWG. The switch leg may be No. 14 AWG if the light load permits. 5. Limit the circuit load for lighting and small appliances on 15 amp and 20 amp circuit loads and 15 amp and 20 amp over current devices respectively. 2.2. Single and Three-Phase Electrical Systems A. SINGLE AND THREE-PHASE ELECTRICAL SYSTEM A single-phase electrical system can either be 2-wire or 3-wire and composed of two hot legs and a neutral wire. The single-phase system are: 1. Two-wire Single Phase DC or AC 13 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. Three-wire Single Phase DC (Edison System) 3. Three-wire Single Phase AC B. THREE-PHASE ELECTRICAL SYSTEM 1. Three-Wire Three-Phase AC 14 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. Four-Wire Three-Phase AC 1.3 Components of the Buildings Electrical System Parts of the Wiring System 15 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao DEFINITION OF TERMS  Equipment - general term including materials, fitting, devices, appliances, fixtures, apparatuses used as part of, or in connection with an electrical installation.  Appliance - currents consuming equipment / fixed or portable ex: heating, cooking & small motor operated equipment.  Fittings – an accessory ex: locknut, bushing, or other part of a wiring system w/c is intended to perform a mechanical rather electrical function. A. SERVICE ENTRANCE2 The point of delivery of electricity to a building by a Public Utility Company. The service entrance consists of the following: 1. Service Conductors These are the conductors with extended from the street distribution main or distribution transformer to the service equipment of the building. https://optimalhomeinspections.com/wordpress/wp-content/uploads/2019/04/TypicalOHservice-1024x551.png 2. Service Equipment  Service Entrance Switch – this affords the means of connecting or disconnecting the entire electrical service and of automatic protection against serve overloads and short circuits.  Kilowatt Hour Meter – The device used by the utility company to determine power consumption. _________________________________________________________________________________ 2 Service Entrance – the conductor and equipment for delivering energy from the electricity supply system to the wiring system of the premises served. 16 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao Ching, F. (2008). The Visual Dictionary of Architecture. https://doi.org/10.5040/9781350096462 17 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao Type of Service Entrance 1. Overhead Service A service drop3 is connected from the nearest utility pole to the building service entrance and enters the building through the weather head or entrance cap down to the electric power meter. 2. Underground Services - consists of a buried concrete enveloped raceway extending from the building to the property line where it is tapped to the main by a service lateral4. The cable recommended is the USE type (Underground Service Entrance) cable. B. MAIN SWITCHBOARD5 The service entrance conductors in the form of bus bars terminate in the main switchboard and connect to the distribution panel boards using feeder circuits protected by circuit breakers. The main switchboard serves for the control, protection, and metering of the main feeders. https://5.imimg.com/data5/XM/AA/ZK/SELLER-3766399/main-switch-board-panels-500x500.jpg _________________________________________________________________________________ 3 Service Drop – The overhead portion of service conductors extending from the nearest utility pole to a building. 4 Service Lateral - The underground portion of service conductors extending from a main power line or transformer to a building. 5 Switchboard or Switchgear - are free-standing assemblies of switches, fuses, and circuit breakers that provide switching and feeder protection to several circuits connected to the main source. 18 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao C. FEEDER CIRCUITS A feeder circuit s a set of conductors which extend from the main switchboard to a distributing center (panel board) with no other circuits connected to it between, the source and the distributing center. At the center, the feeders terminate at panel boards which are lower-capacity switchboards. D. SUB-FEEDER CIRCUITS Are line extensions of a feeder, fed through a panel board or cut-out, from one distributing center to another and having no other circuit connected to it between the two distributing centers. A sub-feeder serves to power from the main feeders to smaller local panel boards, called sub-panel boards. E. BRANCH CIRCUITS These are small-capacity conductors which deliver capacity to lamps, motors, and other loads within the circuit. F. PANEL BOARDS6/SUB-PANEL BOARDS (CUT-OUTS) These serve to control and protect the sub-feeders and brand circuits G. UTILIZATION EQUIPMENT These are lighting, power, motor loads, and wiring devices which are directly handled and utilized by users. https://www.thespruce.com/thmb/QG4SUpXK8rwsAcqdx39OB_QhF_w=/2000x1333/filters:no_upscale()/electrical-service-size-of-my-home-1152752-hero-0a04c3eec7c94154a5e8f116e7fe329f.jpg _________________________________________________________________________________ 6 Panel Board – A single panel or group panel limits designed for assembly in the form of a single panel. (NEC) 19 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao Ching, F. (2008). The Visual Dictionary of Architecture. https://doi.org/10.5040/9781350096462 20 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2.4. Illustrating the Components of the Building Electrical System The major component of a building’s electrical power system may be illustrated in three ways: A. BLOCK DIAGRAM A horizontal single-line diagram of the building’s electrical system from the incoming service to the utilization items at the end of the system where the major electrical components are shown as blocks or rectangles. 21 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao B. SINGLE LINE DIAGRAM When electrical symbols are used instead of the blocks, it is called a “one line” or a “single line diagram”. C. RISER DIAGRAM A vertical line diagram of the major electrical components of the building's electrical system is presented showing the spatial relations between components. 22 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao These major components may be arranged in the diagrams in three major categories: 1. Wiring – which includes conductors and raceways of all types 2. Power Handling Equipment –transformers, panel boards, large switches, and circuit breakers. 3. Utilization Equipment - such as lighting, motors, controls, and wiring devices. 2.5. Emergency Electric Supply System  Emergency Systems - provide electric power and illumination essentially for life safety and protection of property during an emergency, such as electricity for exit lighting, elevators, fire alarm system, fire pumps, and the like. https://img.ecmweb.com/files/base/ebm/ecmweb/image/2019/04/ecmweb_3759_606ecmcbfig1.png?auto=format,compress&fit=fill&fill=blur&w=1200&h=630  Standby System – provides power to selected loads not directly involved with life safety, such as water and sewage treatment plants and industrial machines for manufacturing processes. https://upload.wikimedia.org/wikipedia/commons/5/5b/Backup_Generator.JPG 23 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao A. EMERGENCY POWER EQUIPMENT 1. Battery Equipment - central storage batteries are mounted in individual racks and always provide with automatic charging equipment. The greatest advantage of its use is limited in the duration of emergency power, usually 1 ½ hours. It can, however, start instantaneously and be installed either centrally or installed in small package units strategically located around the building. https://intelligent-charging.com/wp-content/uploads/2018/11/UPS.jpg 2. Engine Generator Sets – are machines intended to produce electricity and are composed of three components: the machine and its housing, the fuel storage tank, and the exhaust facilities. The disadvantages in its use are noise, vibration, nuisance of exhaust, need for constant maintenance, and difficulties in the handling and storage of its fuel. Additionally, it has a longer start-up time compared to batteries. However, it has unlimited KVA capacity and can last a lifetime if properly maintained. https://tiimg.tistatic.com/fp/1/007/466/green-colour-automatic-diesel-engine-generator-set-1500-2500-rpm-075.jpg B. EMERGENCY WIRING SYSTEM USING THE BATTERY 1. Small emergency appliance connected directly to a storage battery. 2. Groups of emergency loads are connected to a central storage battery through the automatic device. 3. Emergency equipment loads are entirely separate from normal loads and are generally de- energized. The contractor is activated when it senses the power loss. 24 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao C. EMERGENCY WIRING SYSTEM USING THE GENERATOR 1. The emergency system handles by a single transfer switch which automatically turns on when it senses power loss at its downstream location. 2. The emergency system is handled by multiple switches. 3. Emergency service is separated from normal through its emergency service entrance, coming from different transformers or feeders. Reliability of the system can only be obtained by minimizing the possibility of a single event interrupting both services. 4. Same as above, but both service entrances supply normal loads, and each act as a standby for the other. 3. ELECTRICAL MATERIALS AND EQUIPMENT 3.1. Conductors These are materials that allow to free flow of electrons through them. Metals generally have the least resistance to the flow of the electric current. The best conductors are precious metals, such as silver, gold, and platinum. Copper and aluminum are the most commonly used materials for conductors. However, since aluminum forms a poorly conductive oxide layer, aluminum is restricted to small wires while copper is preferred in all conductor types. https://conwire.com/assets/PrintedCableJacketPortfolio-retouched-425x318.png A. TYPES OF CONDUCTORS 1. Wires – are single insulated conductors No. 8 AWG (American Wire Gauge or smaller; for the English System, it is the B & S Gauge or Browne and sharp gauge. The smallest size of wire permitted is No.14. https://www.fireflyelectric.com/wp-content/uploads/2022/08/RTN.png 25 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. Cable – are single insulated conductors No.6 AWG or larger; others may be several conductors of any size assembled into a single unit. Wires and cables are either solid or stranded. A stranded wire consists of a group of wires twisted to form a metallic string. A cord is an insulated stranded wire, such as the cord of a flat iron. https://www.dfliq.net/wp-content/uploads/2016/08/Underground-Cables.jpg 3. Bus Bars – large conductors which are not circular in cross- section and are usually found only to supply the main switchboards. https://upload.wikimedia.org/wikipedia/commons/thumb/8/8d/Busbars.jpg/262px-Busbars.jpg B. CONDUCTOR SIZES – AWG/MCM STANDARD All conductor sizes from No. 18 (or AWG 1) to No. 10 (AWG No. 0000, also designated 4/0) are expressed in AWG. Beyond AWG No. 4/0, a different designation, MCM size is 250 MCM or ½ and the biggest is 500 MCM. A circular MIL is an artificial area measurement, representing the square of the cable diameter when the diameter is expressed in mils (thousand of an inch). Thus a solid conductor ½ inch in diameter is 500 mils in diameter, or 250,000 circular mils in area, (500)2 or 250 MCM; thus; CM/1000 = diam2 = (500)2/1000 = 250,000/1000 = 250 MCM In the metric system, conductor sizes are given simply as the diameter in millimeters (mm). 26 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao C. CONDUCTOR AMPACITY Conductor current carrying capacity or ampacity in the maximum operating temperature that is insulation can stand continuously. Heat is generated as a result of the current flowing and the conductor resistance. When conductors are placed in an enclosed conduit. The heat generated is not as easily dissipated as it would be if the conductor were free in the air. Thus, the current rating of a conductor in free air is much higher than that for the same where it is in a conduit. D. TYPES OF CABLE 1. Armored cable (Type AC) – a fabricated assembly of insulated conductors enclosed in a flexible metal sheath. The most common type of AC run without raceways is the NEC- type flexible armored cable known by the trade name BX. https://cdn.automationforum.co/uploads/2023/01/8-2.jpg 2. Metal clad cable (Type MC) – a factory- assembled cable of one or more conductors each individually insulated and enclosed in a metallic sheath of interlocking tape of a smooth or corrugated tube. https://susacdn.azureedge.net/product/Wire/MC_Lite.jpg 3. Mineral insulated cable (Type MI) – a factory-assembled conductor insulated with highly compressed refractory mineral insulation enclosed in a liquid and gas-tight continuous copper sheath. To maintain its integrity, terminations are made with compression rings, glands, and sealing compounds. https://www.hdcablegroup.com/uploads/allimg/220817/1-220QG6123TM.jpg 27 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 4. Non-metallic sheathed cable (Type NM or NMC) – also known by the trade name ROMEX, is a factory assembly of two or more insulated conductors having a moisture-resistant, flame retardant, and non- metallic material outer sheath. For Type NMC, the jacket is additionally corrosion resistance. Since it is non-metallic, it is easier to handle but more vulnerable to physical damage and therefore limited in use to small buildings. https://slideplayer.com/slide/4552805/15/images/12/Nonmetallic+Sheathed+Cable+%28NM%29.jpg 5. Shielded non-metallic Sheathed Cable (Type UF) - a factory assembly of two or more insulated conductors in an extruded core of moisture resistance and flame retardant material covered within an overlapping spiral metal tape. https://www.electricaltechnology.org/wp-content/uploads/2020/04/Three-Wires-Non-metallic-sheathed-Cable.jpg 6. Underground Feeder and Branch Circuit Cable (Type UF) – a moisture resistance cable used for underground connections including direct burial in the ground as a feeder or branch circuit. https://www.servicewire.com/ServiceWire/Imagery/Product-Images/ProductIllustrations/UFB.png?Large 28 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 7. Service Entrance cable (Type SE or USE) – a single or multi-conductor assembly provided with or without an overall covering primarily used for service wire. https://engineer-educators.com/wp-content/uploads/338.2-Definitions-Service-Entrance-Conductor-Assembly.jpg 8. Power and Control Tray Cable (Type TC) – a factory-assembled two or more insulated conductors with or without associated bare or covered grounding under a metallic sheath and is used for installation in cable trays, raceways, or where supported by wire. https://solutions.borderstates.com/wp-content/uploads/2017/04/tray-cable-power-control-labeled.jpg 9. Flat Cable Assemblies (Type FC) – an assembly of parallel conductors formed integrally with an insulating material web designed especially for field installation in square structural channels. https://www.cicoil.com/images/page-content/custom-cables/assemblies-any-full.jpg 10. Flat Conductor Table (Type FCC) - consists of three or more flat copper conductors placed edge to edge separated and enclosed within an insulating assembly. This type of cable is used for appliance or individual branch circuits installed inside floor surfaces. https://m.media-amazon.com/images/I/51W24k353hL._AC_UF1000,1000_QL80_.jpg 29 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 11. Medium Voltage Cable (MV) – a single or multi-conductor solid dielectric insulated cable rated at 2,000 to 3,500 volts. The trade name is Medium Voltage Solid Dielectric. https://i1.wp.com/www.electricalindia.in/wp-content/uploads/2018/07/challenges-mediumvoltage-cabledistributionsystems- cable-cables.jpg?fit=863%2C530&ssl=1 3.2 Insulators Are materials that prevent the flow of electrons through them. Glass, mica, rubber, oil, porcelain, and certain synthetics such as phenolic compounds exhibit this insulating property and are therefore used to insulate electric conductors. Common examples are rubber and plastic wire coverings, porcelain lamp sockets, and oil-immersed switches. Insulation is rated by voltage, for example, 300V, 600V, 1000V, 3000V, 5000V, and 1500V. If insulation is used above its recommended voltage rating, it may break down causing short circuits and arcing with the possibility of fire starting. Ordinary building wiring is usually rated for 300V and 600V. https://engineeringlearn.com/wp-content/uploads/2023/01/Insulators.jpg In general, there are unjacketed types. The unjacketed conductors are those which consist of a copper conductor covered with insulation T (thermoplastic) or TW (Moisture-resistance Thermoplastic). The jacketed ones are the THHN (Heat-resistance thermoplastic) both of which have a nylon jacket designated as N. 30 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao Types of Insulators Trade Name Type Letter Maximum Operating Application Provisions Temperature ̊ Moisture and heat- RHW 75 ̊C̊̊ Dry and Wet location resistance rubber 167 F ̊ Thermoplastic T 60 ̊ C Dry locations 140 ̊ F Moisture-resistance TW 60 ̊C Dry and Wet location thermoplastic 140 ̊ F Heat-resistance THHN 90 ̊ C Dry locations Thermoplastic 194 ̊F Moisture & heat- THW 75 C ̊ Dry and Wet location resistance Thermoplastic 167 F ̊ Moisture & heat- THWN 75 ̊C Dry and Wet location resistance Thermoplastic 167 ̊F Moisture & heat- XHHW 90 ̊C Dry locations resistance cross-linked 194 ̊F thermosetting 75 ̊C Wet Locations polyethylene 167 ̊C Silicon-asbestos SA 90 ̊C Dry locations 194 F ̊ Asbestos and Varnished AVA 110 ̊C Dry locations Cambric 230 F̊ 3.3 Conduits Are circular raceways used to enclose wires and cables and are of metal or plastic (PVC). https://5.imimg.com/data5/BU/WJ/MY-20679700/upvc-electrical-conduit-pipes-500x500.png 31 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao A. PURPOSE OF CONDUITS 1. To protect the enclosed conductors from mechanical injury and chemical damage. 2. To protect people from shock hazards by providing a grounded enclosure. 3. To provide a system ground path. 4. To protect the surroundings against fire hazards as a result of overheating or short- circuiting of the enclosed conductors. 5. To support the conductors. B. TYPES OF STEEL CONDUITS Three types of steel conduits differ basically in their wall thickness, these are: 1. Heavy-wall steel conduits are called “Rigid Steel Conduits” or RSC with an approximate thickness of 0.117 mm. https://www.electrolinefittings.com/images/userfiles/rsc-pic.jpg 2. Intermediate Metal Conduit or IMC with a thickness of 0.071 mm. https://www.evtelectrical.com/uploads/202025231/intermediate-metal-conduit40014465612.jpg 3. Thin-wall steel conduits are named ‘Electric Metal Tubing” or EMT. https://www.evt-electrical.com/uploads/202025231/small/electrical-metallic-tubing38122696017.jpg 32 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao RSCs and IMC use the same fitting, called condulets, and are threaded alike at the joints. EMTs are not threaded but use set screws and pressure fitting and are not recommended for embedding in concrete nor permitted in hazardous areas. IMCs yield a larger inside diameter (ID) for easier wire pulling and are lighter than the RSC. The standard length of steel conduits is 3m of 10 ft. When steel conduits are installed in direct contact with the earth it is advisable to use the hot-dip galvanized type and to coat the joints with asphaltum. 3.4. Raceways (Electrical UPVC Moulding) Channels or wiring accessories so designed for holding wires, cables, and bus bars that are either made of metal, plastic, or any insulating medium. https://primex.com/wp-content/uploads/2018/12/verge-raceway.jpg A. FLOOR RACEWAYS 1. underfloor raceways https://engineering.electrical-equipment.org/wp-content/uploads/2017/07/underground-raceway-server-building.png 33 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. cellular metal floor raceways https://i.ytimg.com/vi/kfqEpxj4-pw/maxresdefault.jpg 3. cellular concrete floor raceways (pre-cast) https://www.kindpng.com/picc/m/14-144411_concrete-frame-display-cellular-concrete-floor-raceway-hd.png B. CEILING RACEWAYS 1. Header ducts (wire ways) https://nassaunationalcable.com/cdn/shop/articles/istockphoto-497451051-612x612_612x.jpg?v=1646036341 2. Distribution ducts (laterals) https://www.industrial-electronics.com/engineering-industrial/images/mech-elec_27-17.jpg 34 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 3.5. Outlets and Receptacles An outlet is a point in the wiring system at which current is taken to supply utilization equipment. It refers only to the box. A receptacle is the wiring device1 in which the utilization equipment (appliance) cord is plugged into. A. KINDS OF OUTLETS 1. Convenience Outlet or Attachment Cap - the complete setup which establishes a connection between the conductor of the flexible cord and the conductors connected permanently to the receptacle. The common wall outlet is a convenience outlet. https://www.thespruce.com/thmb/4Z6C8xu91-ODn02hiVhtEMtRlhA=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/how-to-wire-an-outlet-1152325-hero-f184ed9c5eca4db490656bf5f32e438f.jpg 2. Lighting Outlet - is an outlet intended for direct connection to a lamp holder lighting fixture, or pendant cord terminating in a lamp holder. https://new.abb.com/images/librariesprovider84/Products/LPWA/filpwa/Other-in-text/dcl-ripustuskansi-uppoasennukseen_560px.jpg?sfvrsn=3838e310_2 _________________________________________________________________________________ 1 Wiring Device - includes all devices that are normally installed in wall outlet boxes, including receptacles, switches dimmers, pillar lights, attachment plugs, and wall plates. 35 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 3. Receptacle Outlet - an outlet where one or more receptacles are installed. https://qph.cf2.quoracdn.net/main-qimg-487d9eb41e25f9bb54bd4dca54c1e5be RECEPTACLES2 Are contact devices installed at the outlet for the connection of a single attachment plug. It includes all receptacles and their matching cap (plug), wall switches, small dimmers, and outlet box-mounted lamps. 3.6 Switches Are devices for making, breaking, or changing conditions in an electrical circuit under the conditions of load which they are rated, Switches are rated according to current and voltage, duty, poles and throw, fusibility and enclosure Switches may be classified as follows: https://www.electronicshub.org/wp-content/uploads/2021/05/Configuration-of-Switches-by-Function.jpg A. TYPE OF SWITCH - ACCORDING TO VOLTAGE Switches are rated as 260V, 500V. Or 5KV as required. B. TYPE OF SWITCH - ACCORDING TO INTENSITY OF USE 1. Normal Duty (ND) - intended for normal use in light and power circuits as in general-purpose switches. 2. Heavy Duty (HD) - intended for frequent interrupting. 3. Light Duty (LD) - intended to connect the loads occasionally, such as service switches. _________________________________________________________________________________ 2 Receptacle - A contact device installed at the outlet for the connection of a single attachment plug. (NEC) 36 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao C. TYPE OF SWITCH - ACCORDING TO TYPE OF SERVICE 1. Service Switch - intended to disconnect all the electric service in the building except emergency equipment. This may comprise one to six properly rated switches that are assembled into a switchboard. 2. Power Switches a. General-purpose Switches - are intended for use in general distribution and branch circuits. b. Disconnecting or Isolating Switches are intended for disconnecting or isolating circuits: used for circuits rated at more than 600 volts. 3. Wiring Switches include all the relatively small switches that are employed in interior wiring installations for the control of branch circuits, individual lamps, or appliances. a. General-purpose Switches are single-pole or double-pole switches for the general-purpose use of connecting or cutting-off circuits for the control of lamps or other loads from a single point. b. Three-way Switches - are used where it is desired to control lamps from two different points as in a stairwell. c. Four-way Switches - are used in conjunction with two 3-wire switches where it is desired to control lamps from three or more desired points d. Electrolier or Multi-circuit Switches - are used for the control of lights in multi-lamp fixtures so that one lamp or set of lamps may be turned on alone or in combination with other lamps. e. Momentary Contact Switches - are used where it is desired to connect or cut off a circuit for only a short duration. The switch is provided with a spring so that it will return to its original position as soon as the handle or button is released. Ex. Doorbell f. Dimmer Switches - a rheostat3 or similar device for regulating the intensity of an electric light without appreciably affecting spatial distribution. Also called a dimmer. Wiring switches may either be the flush type, surface type, or pendant type. _________________________________________________________________________________ 3 Rheostat - a resistor for regulating a current by means of variable resistances. 37 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao D. TYPE OF SWITCH - ACCORDING TO OPERATION MECHANISM Wiring switches may also be classified according to the operating mechanism as: 1. Rotary switch 2. Push-button switch 3. Toggle or tumbler switch https://img.mweb.com.tw/thumb/526/600x600/Products/Rotary- https://res.cloudinary.com/rsc/image/upload/b_rgb:FFFFFF,c_pad,dpr_2.62 https://down- Cam-Switch/Rotary-Cam-Switch-40A/40a-multi-step-switches- 5,f_auto,h_535,q_auto,w_950/c_pad,h_535,w_950/F4355679- ph.img.susercontent.com/file/e74b29cba95e0361c1e9b766e5e975e6 without-off-2.jpg 01?pgw=1&pgwact=1 Rotary Switch Push Button Switch Toggle Switch E. TYPE OF SWITCH - ACCORDING TO NUMBER OF POLES AND THROWS 1. Poles - that part of the switch which is used for making or breaking a connection and which is electrically insulated from other contact-making or breaking parts. Switches are available in 1, 2, 3, 4, and 5 pole construction. 2. Throws - a single-throw switch will make a closed circuit only when the switch is thrown in one position. A double-throw switch will make a closed circuit when thrown in either of two positions. Double throw switches are often used to transfer a load from one source to another for example from normal to emergency supply or from one feeder to an alternate. F. SPECIAL SWITCHES 1. Time-Controlled Switches - This device comprises a precision low-speed miniature drive motor (timer) to which some type of electric contact-making device is connected. https://5.imimg.com/data5/FE/WJ/QF/SELLER-55807083/l-t-gic-j648b1-time-switch-500x500.jpg 38 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. Remote Control (RC) Switches -A contactor4, or more specifically, a relay5, that latches after being operated wireless from a distance. https://www.maketheswitch.ph/cdn/shop/products/remote.jpg?v=1610687717 3. Air Switch - a switch in which the interruption of a circuit occurs in the air. https://m.media-amazon.com/images/I/71pINPZxHPL.jpg 4. Knife Switch - a form of air switch in which a hinged copper blade is placed between two contact clips. https://m.media-amazon.com/images/I/61A+fXSC98L._AC_UF1000,1000_QL80_.jpg https://res.cloudinary.com/rspoc/image/upload/f_auto/q_auto/v1672927707/RS%20CONTENTFUL/Discovery/ https://4.imimg.com/data4/WR/IJ/MY-26347330/electric-power-contractor-d-model-500x500.jpg Other%20image%20assets/rheostats-static-image.jpg Rheostat Contractor _________________________________________________________________________________ 4 Contractor - is a switch device. Instead of a handle-operated, movable blade and a fixed grip a contractor used blocks of silver-coated copper which are forced together to make or break a circuit. 5 Relay – is a small electrically operated contactor. 39 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 5. Float Switch - a switch controlled by a conductor floating in a liquid. https://i.ytimg.com/vi/7Ypl2j0Sjjs/maxresdefault.jpg 6. Mercury Switch - an especially quiet switch that opens and closes an electric circuit by shifting a sealed glass tube of mercury to uncover or cover the contacts. 7. Key Switch - a switch operated only by inserting a key or a card. Also called a card switch. https://m.media-amazon.com/images/I/31Wr4Cg6kuL.jpg 8. Automatic transfer Switch (ATS) - This device, an essential part of an emergency or standby service, is a double throw switch, generally a 3-pole, so arranged that on the failure of normal power, emergency service is automatically supplied. https://www.electric-hc.com/Uploads/5ced3dbca0bb24988.jpg 40 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 3.7. Wall Plates or Faceplates6/Cover plates These are coverings for switches and wall outlets usually made of metal or phenolic compound (Bakelite). Wall plates are single-gang, two-gang, and three-gang. https://contentgrid.homedepot-static.com/hdus/en_US/DTCCOMNEW/Articles/types-of-wall-plates-section-12.jpg https://contentgrid.homedepot-static.com/hdus/en_US/DTCCOMNEW/Articles/types-of-wall-plates-section-11.jpg 3.8. Over-current Circuit Protective Devices These are devices whose sole purpose is to protect insulation wiring, switches, and other apparatus from overheating or burning, due to overloads, faults, or short circuits, by automatically cutting off the circuit. The two most common devices used are the fuse and the circuit breaker. While panel boards and switchboards or switchgear compose an assembly of fuses or circuit breakers. https://eepower.com/uploads/articles/OCPD_Pic_figure3.png _________________________________________________________________________________ 6 Faceplate – a protective plate surrounding an electric outlet or light switch. 41 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao A. FUSE7 A device consisting of an alloy link of wire with a low melting temperature which is inserted in the circuit, in such a way that all current which passes through the circuit must also pass through this metal. Any current which would be dangerous to the circuit melts this fuse, opens the circuit at this point, and thus protects the rest of the components from the effects of the current. The cause of the large current may then be removed and a new fuse inserted in place of the broken one. https://cpimg.tistatic.com/02324550/b/5/Fuse.jpg TYPES OF FUSES: 1. Plug Fuse - type enclosed in a porcelain cap used in circuits not exceeding 125 volts. The current rating is from 10 - 30 amperes. 2. Cartridge Fuse - type enclosed in an insulating fiber tube. a. Cartridge type with ferrule contacts - 250 to 600 volts, current rating of from 5-60 amperes. b. Cartridge type with knife blade contacts - 250 to 600 volts: current rating from 70 to 600 amperes. https://components101.com/sites/default/files/components/Different-Types-of-Fuses.jpg c. Cartridge type with bolted knife blade contacts - 500 volts, current ratings from 300 to 3000 amperes. 3. Open Link Fuse - This consists of a wire or strip of easily melted metal. It has the disadvantage of disrupting violently when a short circuit occurs. It is allowed only on sizes smaller than 600 amps and must be placed in a cabinet. Fuses may also be classified as "one-time use and renewable". The renewable fuse may be disassembled and a new fuse link inserted to replace the one within. The general rule is that a wire rated to carry a definite number of amperes should be protected by a fuse of a lower or similar rating. _________________________________________________________________________________ 7 Fuse – an overall current protective device with a circuit opening fusible element that breaks when there is an over current in the circuit. 42 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao STANDARD TYPE OF FUSES 1. Nonrenewable plug fuse 2. Nonrenewable knife blade fuse 3. Nonrenewable dual element time delay ferrule cartridge fuses 4. Nonrenewable high interrupting capacity current limiting fuse (dual element) 5. Nonrenewable miniature fuse B. CIRCUIT BREAKERS8 An over-current protective device is designed to function as a switch, or it can be manually tripped and thus act as a circuit switch. It breaks a circuit with an automatic tripping9 device without injury to itself. It is not self-destructive on operation, as the fuse is, and it can be reset after tripping by merely operating its handle. https://www.omniphilippines.com.ph/wp-content/uploads/2016/12/CBB-2P-15A-3-1010x1024.png TRIPPING Most circuit breakers are equipped with both thermal and magnetic trips. 1. Thermal Trip - similar in action to a thermostat10. The heat generated by excessive current causes an element to move and trip the latching mechanic of the breaker thus opening the breaker contacts and thereby the circuit. 2. Magnetic Trip - comprises a coil with a movable core. On short circuits, magnetic forces actuate the core which trips the circuit breaker latch. _________________________________________________________________________________ 8 Circuit Breaker –an electrical safety device designed to protect an electrical circuit from damage caused by overcurrent. 9 Trip or Tripping – refers to the cutting-off or disconnection of the current electric supply. 10 Thermostat – an instrument, which responds to changes in temperature and consists of sensitive elements, which expand and contract according to the degree of heat. The movement may make or break an electric current or may close and open a small port in a compressed air line. 43 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao C. GROUND FAULT CIRCUIT INTERRUPTERS (GFCI OR GFI) Is an over-current protective device that will provide ground fault protection as well as function as an ordinary circuit breaker. https://cdn-ganda.nitrocdn.com/UOUeYyqWCqliZVPzHjXTQFUrByTzEEDs/assets/images/optimized/rev-c6f590c/makeitright.ca/wp-content/uploads/2022/06/MHI_electrical_0007_03-COM-1024x682.jpg D. GUIDELINES FOR THE USE OF OVERCURRENT DEVICES 1. Overcurrent devices must be placed on the line side11 (or supply side) of the equipment being protected. 2. Overcurrent devices must be placed in all ungrounded conductors of the protected circuit. 3. All equipment should be protected in accordance with their respective current carrying capacity. E. PANELBOARDS Popularly known as "panel" or "electrical panel, it is simply the box wherein the protective devices are housed from which the circuits and bus bars terminate. If the devices are fuses, it is called a "Fuse Panel" and if the devices are circuit breakers, it is called a "Breaker Panel". Fuses and breakers are rarely housed in the same box, except that a Breaker Panel may sometimes have a main switch and a fuse for overall protection of the panel. There are many formats of panel schedules (or specifications, the layout of the panel) and this is called the "Schedule of Choice”. https://down-ph.img.susercontent.com/file/d32a8c40c11f3b8e30be822a26f3a35b _________________________________________________________________________________ 11 Line side - refers to the upstream side of a load or device or it refers to where the current downstream side of the device is called the "Load Side". 44 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao TYPES OF PANELBOARDS Panelboards are classified according to use as either: 1. Lighting Panelboards (LP) 2. Power or Motor Panelboards (PP) 3. Distribution Panelboards (DP) They may be further classified as "Flush Type" or "Surface Type" PANELBOARD LOCATION 1. A 1.00 m high or less panel board should be located 1.35M from the floor to its centerline. 2. A panel board over 1.00 m high should be located 75 cm from the floor to the bottom of the box, except that the highest branch circuit connection should not be more than 1.95 M from the floor. 3. If necessary the 75 cm can be lowered to 45 cm with the same restrictions as in No 2. If these requirements cannot be followed, the panel should be divided into two sections. 4. If two or more panels are adjacent to the same wall, the centerlines of each box should be equidistant. In addition, panel boxes should be installed with a minimum spacing of 10 cm apart. F. SWITCHBOARDS Are free-standing assemblies of switches, fuses, and/or circuit breakers whose function normally is to provide switching and feeder protection to a number of circuits connected to a main source. https://1.bp.blogspot.com/-UK2kJ2hrWZ0/YGY6Z8TsKyI/AAAAAAAAHDw/-wlrjrBwPtcXgPn2XhdD5ToiXLUvbe4ygCLcBGAsYHQ/w1200-h630-p-k-no-nu/3.JPG TYPES OF SWITCHBOARDS 1. Live Front - all the current carrying parts of the switching equipment are mounted on the exposed face or front of the panel. 2. Dead Front - all live parts are installed behind the panel, and the operator controls the switches breakers, and other devices by means of insulated handles extending through holes in the front face. 45 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao G. UNIT SUBSTATIONS (Transfer Load Centers) an assembly of primary switch-fuse- breaker, stop-down transformer meters, controls, bus bars, and secondary switchboard. It is used to supply power from a primary voltage line to any large facility. https://www.eaton.com/content/dam/eaton/products/medium-voltage-power-distribution-control-systems/ust-/secondary-unit-sub-skid.jpg 4. WIRING SYSTEMS 4.1. Wiring Methods A. KNOB AND TUBE WIRING An obsolete wiring system consisting of single insulated conductors secured to and supported on porcelain knobs and tubes. When wires run through walls they are inserted into a nonmetallic fire-resistant tubing called a loom. https://structuretech.com/wp-content/uploads/2019/07/knobs-and-tubes.jpg B. RIGID METAL CONDUIT WIRING The best and most expensive among the usual type of wiring. Its advantages are: 1. it is fireproof; 2. moisture-proof; 3. it is mechanically strong so that nails cannot be driven through it and it is not readily deformed by blows; 4. it resists the normal action of cement when embedded in concrete or masonry. https://d2u8t4k4.stackpathcdn.com/wp-content/uploads/2020/03/Advantages-of-Using-Steel-Condui-1200x675.jpg To provide access to the conduits, for installing the necessary wires and making connections to them, they are interrupted at frequent intervals by sheet metal boxes with knockout12 holes. These boxes are called pull boxes, connection or outlet boxes, or junction boxes. The most common sizes are the 4" square and 4" octagonal boxes used for fixtures, junctions, and devices and the 4" x 2-1/2" box used where splicing is not required. ________________________________________________________________________________________________________________________________ 12 Knockout - a panel in a casing or box that can readily be removed, by punching, hammering, or cutting to provide an opening into the interior. 46 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao https://silverrosehardware.com/wp- https://www.thespruce.com/thmb/Z_8NAORTP1g2l7kptq- content/uploads/2017/08/Pull-Box.jpg nRDVtZis=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/electric https://down- al-switch-and-junction-boxes-1824666_01_metal_plastic_3236- ph.img.susercontent.com/file/19e1ac673bf00e2d2f434184d346be 93f0f8ea1a584138942bb2e65209ddda.jpg 4d Pull Box Connection or Outlet Boxes Junction Boxes In running branch circuits from the panel board to the local lamp or plug outlets, 3 or 4 circuits (6 to 8 wires) may be run in one large conduit to a given pull box, then branch off into smaller conduits to the final outlet points. It is not good practice to have more than 8 conductors in a given circuit. Recommended conduit size depends upon the number and diameter of the wires drawn inside the conduit. The number and radius of bends in the conduit, as well as the total length, affect the degree of abrasion to insulation when the wire is inserted and pulled out. There should not be more than 2 -90 deg, or 3 - 45 deg bends in any continuous run. Long, straight pulls may be made through as much as 150-250 ft (50-83mts) of continuous 10 ft. conduits joined by couplings without bends. For exposed conduit work, 9 large varieties of conduit fittings are available. These fittings are called condulets. And depending on the size, to connect wires or cables, they are either permanently spliced or joined together using a connector13. Rigid Non-Metallic Conduit - A separate classification for rigid conduits are those that are of such materials as fiber, asbestos-cement, soapstone, rigid polyvinyl chloride (PVC), and high-density polyethylene. C. FLEXIBLE METAL CONDUIT WIRING Its installation is much easier and quicker than that of rigid metal conduits. Unlike the rigid conduits which come in short lengths of 10 ft (3 M), flexible metal conduit wiring comes in lengths of 25 ft - 250 ft (8 M-83 M) depending on the size of the conduit. The conduit is easily fixed with pipe straps or clamps when turns are required and requires no elbow fittings. https://static.wixstatic.com/media/545e2c_2f91732b889643c7a62f43053be193c0~mv2.jpg/v1/fill/w_1000,h_667,al_c,q_85,usm_0.66_1.00_0.01/545e2c_2f91732b889643c7a62f43053be193c0~mv2.jpg _________________________________________________________________________________ Connector – is an electromechanical device used to create an electrical connection between parts of 13 an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit. 47 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao Liquid-light Flexible Metal Conduit - same construction as the flexible conduit except that it is covered with a liquid-light jacket. The trade name "Sealtite" refers to this product. https://www.anacondasealtite.com/wp-content/uploads/09152022-UL-listed-SEALTITE-500x667.png D. ARMORED CABLE WIRING (BX WIRING) Consists of rubber or thermoplastic-covered wire protected from injury to a certain extent from dampness by one or two layers of flexible steel armor It is different from flexible metal conduit wiring, in that the BX wires and their flexible armor are installed as a unit such that the wires cannot be removed from the armor without destroying the armor. https://healthybuildingscience.com/wp-content/uploads/2013/01/bx-02cw.jpg E. SURFACE METAL RACEWAY WIRING The wires are supported on a thin sheet of steel casing. The raceway is installed exposed, being mounted on the walls or ceiling Metal raceways must be continuous from outlet to outlet or junction box, designed especially for use with metal raceways. https://hubbellcdn.com/prodimage300/WDK_ElectricalElectronic_WireCableMgt_Raceway_Metal_Base-Cover_300.jpg F. FLAT CABLE ASSEMBLIES A field-installed rigidly mounted square structural channel (1 - 5/8" standard) designed to carry 2 to 4 conductors (No. 10 AWG) and will act as light-duty (branch circuit) plug-in busways14. _____________________________________________________________________________________________________________________________ ___ Busway – a rigid metal housing for a group of buses insulated from each other and the enclosure. 14 Also called a “bus duct”. 48 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao G. LIGHTING TRACK A factory-assembled channel with conductors for one to four circuits permanently installed in the track that will act as light-duty (branch circuit) plug-in busways. It is the factory- assembled version of a flat cable assembly. https://contentgrid.homedepot-static.com/hdus/en_US/DTCCOMNEW/Articles/types-of-track-lighting-2022-section-3.jpg H. CABLE TRAY/OPEN RACEWAY Continuous open support for approved cables. When used as a general wiring system, the cables must be self-protected, jacketed types, type TC. https://www.wireandcabletips.com/wp-content/uploads/2014/07/Cable-Tray_App-web.jpg I. FLOOR RACEWAYS The NEC recognizes three types of floor raceways. 1. Underfloor Ducts (UF) - installed beneath or flush with the floor and are available in two basic designs - the single level, where system components such as the feeder ducts, the distribution ducts, the junction boxes, and the floor outlets are on the same level and the two- level system, where the feeder and distribution ducts are on different levels thus eliminating the necessity for complex junction boxes. These underfloor ducts usually require a triple duct system for power, telephone, and signal cabling. https://i.pinimg.com/originals/32/9f/af/329faf381134ceabb5b30357327e3d5b.jpg 49 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 2. Cellular Metal Floor Raceway - Found usually in office landscaping, it is an integrated structural/electrical system in a cellular metal floor. https://i.pinimg.com/1200x/bf/e3/8e/bfe38ec8110a6e9d029817ba9de3c66b.jpg 3. Precast Cellular Concrete - made of concrete cells fed from header ducts, which are normally installed in concrete fill above the hollow core structural slab or fed from the ceiling void below. The cells15 can be used for air distribution and piping. https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQhO_J396wjIUaCij_iOufPc9s3maPRO7gaKTYGhR-H3c1PqZNpK6udobU8Kel2HLk0SmM&usqp=CAU J. CEILING RACEWAY SYSTEMS Under-the-ceiling raceways composed of header ducts and distribution ducts separate for power and telephone cabling. They permit very rapid changes in layouts at low cost and are therefore particularly desirable in stores where frequent display transformations necessitate corresponding electrical facility adjustments. https://www.northernarchitecture.us/climate-control/images/2967_175_225-overhead-raceway-with-lights.jpg ________________________________________________________________________________________________________________________________ 15 Cell – a single, enclosed, tubular space in a floor made of precast cellular concrete slabs, the direction of the cell being parallel to the direction of the floor member. 50 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao K. PRE-WIRED CEILING DISTRIBUTION SYSTEMS Ceiling raceways that are pre-wired in the factory and plugged in where required. https://www.industrial-electronics.com/engineering-industrial/images/mech-elec_27-21.jpg 4.2. Wiring Design House Wiring Installation has been addressed by the NEC under the following specific provisions: 1. Wiring shall be of types RHW. T, THW, TW, THWN, and XHHW. 2. On a 15-amp circuit, a single appliance shall not draw a maximum of 12 amps: on a 20-amp circuit, a maximum of 18-amp appliance and on a 30-amp circuit, a single appliance draw shall not exceed 24 amperes. 3. If a branch circuit is combined with lighting or portable appliances, any fixed appliance shall not be allowed to draw more than 7.5 amps on a 15-amp circuit and 10 amps on a 20-amp circuit. 4. A heavy lamp holder shall be rated not less than 750 watts. 5. A 30, 40, and 50-amp circuit shall not be used for fixed lighting in residences. 6. For appliances used continuously for long periods of time (ie. motors, pumps, and air- conditioners), their actual loads shall be computed not to exceed 80% of the fuse rating. 7. A continuous type load shall be considered at 125% of the actual load in all load calculations. 8. A single receptacle on an individual branch circuit shall have a rating of not less than the circuit. 9. Receptacles feeding portable and steady appliances shall be limited to loads 80% of their rating that is: 12 amp for a 15 amp receptacle 16 amp for a 20 amp receptacle 24 amp for a 30 amp receptacle 10. The number of outlets in a circuit shall be limited to: 6 outlets on a 15 amp circuit 8 outlets on a 20 amp circuit 51 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 4.3. Wiring Symbols 52 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 4.4. Lighting Layout 53 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 4.5. Power Layout 54 | P a g e AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao 4.6. Electrical Regulations as per PD 1096 1. OVERHEAD SERVICE ENTRANCE In Subdivisions Housing Projects, and Commercial and Industrial Buildings, overhead transmission and distribution voltages are required to supply power sources including transformers, poles, and supporting structures. 2. ATTACHMENTS ON AND CLEARANCES FROM BUILDINGS a. An Attachment Plan approved by Professional Electrical Engineer shall cover power lines and cables, transformers, and other electrical equipment installed on or in buildings and shall be submitted to the local Building Official. b. Where buildings exceed 15M in height overhead lines shall be arranged where practicable so that clear space or zone at least 1.80M horizontal will be left adjacent to the building or beginning not over 2.45M horizontal from the building to facilitate the raising of ladders where necessary for firefighting. Exception: This requirement does not apply where it is the rule of the local fire department to exclude other restricted places, which are generally occupied by supply lines. 3. OPEN SUPPLY CONDUCTORS ATTACHED TO BUILDINGS Where the permanent attachment of open supply conductors to any class of buildings is necessary to service entrance such conductors shall meet the following requirements: a. Conductors of more than 300 volts to ground shall not be carried along or near the surface of the building unless they are guarded or made inaccessible. b. To promote safety to the general public and to employees not authorized to approach conductors and other current-carrying parts of electric supply lines, such parts shall be arranged to provide adequate clearance from the ground or other space generally accessible or shall be provided with guards to isolate persons effectively from accidental contact. 55 | P a g e  AR 353 BUILDING UTILITIES 2 (ELECTRICAL, ELECTRONICS, AND MECHANICAL SYSTEMS) AAParungao c. Undergrounded service conduits, metal fixtures, and similar noncurrent-carrying parts, if located in urban districts and where liable to become charged to more than 300 volts to ground, shall be isolated or guarded so as not to be exposed to accidental contact by unauthorized persons. As an alternative to isolation or guarding, noncurrent carrying parts shall be solidly or effectively grounded. d. Service drops passing over a roof shall be securely supported by substantial structures. Where practicable, such supports shall be independent of the building. 4. CONDUCTORS PASSING BY OR OVER BUILDINGS a. Unguarded or accessible supply conductors carrying voltages in excess of 300 volts may be run either beside or over buildings. The vertical or horizontal clearance to any building or its attachments (balconies, platforms, etc.) shall be as listed in the next slides. The horizontal clearance governs above the roof level to the point where the diagonal equals the vertical clearance requirement. This rule should not be interpreted as restricting the installation of a trolley contact conductor over the approximate center line of the track it serves. Clearance of Insulated Supply cables Unguarded Supply cables Open supply Unguarded Communicati from 0 to 750 rigid over 750 V; conductors; rigid on conductors V energized open supply over 750 V to energized and cables; parts, 0 to 750 conductors, 0 22 Kv parts over 750 messengers; (mm) V; non- to 750 V V to 22 Kv surge insulated (mm) protection communicatio (mm) (mm) wires; n conductors grounded (mm) guys; neutral conductors Buildings Horizontal (1) To walls, 1400 1500 1500 1700 2300 2000 projection, and guarded windows (2) To 1400 1500 1500 1700