reference of 111ELECTRICAL WIRING-1.pptx

Engineering

1. ELECTRICAL WIRING

2. WHAT IS ELECTRICAL WIRING It’s the system of cables and conductors that deliver electricity to outlets, appliances and lights in a building. CO NTENT • Electrical wiring types • Electrical wiring systems • Components of electrical wiring systems • Electrical wiring color coding • Safety considerations for electrical wiring (i)ELECTRICAL WIRING TYPES There are different types of electrical wiring, each with its own unique properties and applications: Non- metallic(NM) sheathed cable Also known as Romex or home run cable, it is the most common type of electrical wiring used in residential and commercial building. It consist of two or three insulated conductors typically made of copper or aluminium encased in a plastic sheath typically used for branch circuits which supply power to outlets and appliances. It is easy to install and relatively expensive, making it a popular choice for a wide variety of application

3. THHN and THWN wire THHN & THWN wires are individual insulated conductors typically made of copper or aluminium that are designed for use in conduit or other enclosures they more durable than NM cable and can withstand higher temperatures. THHN wire is rated for use in dry location while THWN wire is rated for use in both dry and wet location AMORED CABLE( BX cable) Is a type of cable that has metal sheath around the insulated conductors. This sheath provides additional protection against damage and can also be used as grounding conductor. Often used in areas where there is risk of physical damage to the cable such as floors or walls ¸

4. MINERAL INSULATED(MI) cable It’s a type of cable that has a mineral insulation around the conductors. This insulation is fire resistant and can withstand very high temperatures. MI cables is often used in industrial and commercial application where fire safety is a major concern METAL CLAD Cable(MC) Is a type of cable that has a metal sheath around the insulated conductor and additional layer of insulation around the sheath which protects the cable from electromagnetic interference Typically used in commercial and industrial application

5. SERVICE ENTRANCE (SE) cable Used to connect the power supply from the utility company to the electrical service panel in a building. Ac cable is rated for outdoor use and can withstand the harsh environmental conditions UNDERGROUND FEEDER(UF)cable It’s a type of cable that is used to bury underground. UF cable is rated for direct burial and can withstand the moisture and pressure of the soil. SOLAR CABLE Designed for solar power applications, resistant to sunlight and built to withstand environmental conditions. Used to connect solar panels and components in photovoltaic systems

6. COAXIAL CABLE It’s a type of cable that is used to transmit high frequency signals. Consists of a central conductor surrounded by a layer of insulation and then an outer conductor surrounded by protective sheath. Often used in cable television, satellite, tv, and high speed internet connection FIBRE OPTIC CABLE Type of cable that uses pulses of light to transmit data. This type of cable is very fast and can transmit large amount of data over long distances. Often used for telecommunications, computer networks and cable television.

7. (ii)ELECTRICAL WIRING SYSTEMS a)Concealed wiring This type of wiring is installed inside walls , ceilings and floors. It is the most common type of wiring in residential and commercial buildings as it is safe and aesthetically pleasing. b)surface wiring This type of wiring is installed on the surface of walls , ceilings and floors. It is less common than concealed wiring but it is sometimes used in older buildings or in areas where it is difficult to run wires into the walls

8. c)Conduit wiring This type of wiring is installed inside a conduit, which is a metal or plastic pipe. Conduit wiring is often used in industrial and commercial buildings, as it protects wires from damage and makes it easy to add or remove wires in the future. Concealed conduit wiring d)open wiring This type of wiring is installed without any protection. Open wiring is only used in very limited applications, such asin temporary installations or in areas where there is no risk of damage.

9. e)Cable wiring Generally refers to the installation and arrangement of electrical cables within a building or structure Electrical cables consists of conductors (wires)insulated from each other and the surrounding i. Types of cables Power cables- designed to carry power from one point to another ii. Control cables-used to transmit control signals to operate and control equipment and machinery iii. Communication cables-used for data transmission in networking and telecommunications iv. Specialized cables-for specific applications, such as fire-resistant cables , high temperature cables

10. (iii)COMPONENTS OF ELECTRICAL WIRING SYSTEMS They include conductors, insulators and protective coverings Are materials that allow electricity to flow a)Conductors The most common include copper, aluminium and silver (i )Co pper Is the most common used conductor for electrical wiring It is highly conductive, ductile and malleable, making it easy to work with (ii) A luminium Is a lighter and less expensive alternative to copper However, it is not as conductive as copper , so it must be used in larger sizes to carry the same amount of current (iii )Silver Is the most conductive metal, but is also the most expensive Silver is only used in special applications where high conductivity is critical ( b)Insulators Are materials that prevent electricity from flowing from one conductor to another The most common include PVC, rubber, XPLE(cross-linked polyethylene)

11. ( i)Polyvinyl Chloride(PVC) Is a common insulator that is inexpensive and easy to work with . It is rated for use in a wide range of temperatures and environment (ii )rubber Is flexible and resistant to moisture. Often used for appliance cords and other applications where flexibility is important ( i ii)XPLE Is a newer insulation material with excellent flame resistance, dielectric properties and resistance to moisture and chemicals

12. (c)Protective Devices They safeguard against electrical hazards and prevent damage to equipment and property. They operate by interrupting the flow of electricity when abnormal conditions arise, such as overloads, short circuits, or ground faults a) Fuses-contain a thin, easily melted wire that acts as a sacrificial element. When an overload or short circuit occurs, the fuse melts, breaking the circuit and preventing further damage a) Circuit breakers –are more sophisticated protective devises that can be manually reset after tripping. They use an electromagnet or mechanical mechanism to detect overloads or faults and interrupt the circuit accordingly. a) Grounding –grounding provides a low-resistance path for fault currents to flow to the earth, preventing them from travelling through the building structure or causing shocks.

13. Other components include: v Switches-they control the flow of electicity to specific circuits or devices, allowing users to turn lights on and off or operate app liances v Conduit-is a protective pipe or tube that encases wiring, providing protection against physical damage and environmental fac tors v Distribution boards-also known as fuse boxes or breaker panels, house the circuit breakers or fuses that protect individual circuits. They also distribute power to various branch circuits within the building v Receptacles(outlets)-provide points of connection for electrical devices to plug into the wiring system

14. (iv)ELECTRICAL WIRING COLOR CODING. Electrical wiring is color-coded to help electricians identify the different types of conductors. The most common color codes are Ø Black- hot or live, carry power from source to load, connect to brass terminals. Ø Red-hot or live, carry power from the different circuit or phase, used for for switch legs or interconnections Ø White or Grey-neutral , return current from the load to the source, connect to silver to terminals, bounded to ground Ø Blue or yellow wires – hot or live carry power for specific purposes or device, used as travelers in switch configuration Ø Green or green with yellow stripe - ground wire, provide a low resistant part for electrical current to flow to the earth in the event of a fault, this helps to protect people and the equipment from electrical shock and fires.

15. (v)SAFETY CONSIDERATIONS FOR ELECTRICAL WIRING Electrical wiring can pose significant safety hazards if not installed and maintained correctly. Always allow safety precautions, including: • Turning of the power before working on the electrical wiring • • Use appropriate tools and protective gear Seek professional assistance for complex electrical work • Regularly inspect and maintain electrical wiring