Electrical Work PDF

DUHOK POLYTECHNIC UNIVERSITY DUHOK TECHNICAL INSTITUTE BUILDING CONSTRUCTION TECHNOLOGY DEPT. BUILDING SERVICES ELECTRICAL SERVICES ASST. LEC. BAYAN A.TAHA SECOND YEAR FIRST SEMESTER 2024-2025...

DUHOK POLYTECHNIC UNIVERSITY DUHOK TECHNICAL INSTITUTE BUILDING CONSTRUCTION TECHNOLOGY DEPT. BUILDING SERVICES ELECTRICAL SERVICES ASST. LEC. BAYAN A.TAHA SECOND YEAR FIRST SEMESTER 2024-2025 Lecturer: Bayan A.Taha 1  Introduction : Electrical services is an mode which provides us the electricity that is required by us to run electrical appliances, in industries to provide electricity to run the machineries , in commercial places to run the mechanical services. Displays etc. Use of electricity: Residential Building: Lights , Fans, Heaters, Television, Refrigerators etc. Industrial Buildings: Machineries, Welding, Electroplating etc. Commercial Buildings: Lifts, Escalators, Alarm Systems, Advertising Lecturer: Bayan A.Taha 2 Electric Generator Electricity generation is defined as electricity generated from fossil fuels, nuclear power plants, hydro power plants geothermal systems, solar panels, biofuels, wind, etc Transformer step up several thousands or even hundreds of thousands of volts before it is supplied to the transmission lines or cable. By transmitting electricity at high voltages less power is lost in the cables. At the receiving end of voltage is stepped down by transforms in local sub-stations to consumers at 240 volts. Lecturer: Bayan A.Taha 3  Transformers  A transformer can accept energy at one voltage and deliver it at another voltage.  This permits electrical energy to be generated at relatively low voltages and transmitted at high voltages and low currents, thus reducing line losses and voltage drop Location of the transformer  Location of the transformer is very important as far as distribution loss is concerned.  Transformers should be placed close to the load center, considering other features like optimization needs for centralized control, operational flexibility etc. This will bring down the distribution loss in cables 4 Lecturer: Bayan A.Taha  Entry in the buildings In Urban areas electrical cables are Usually underground and are brought up to entry point at ground level or into basement service cable cannot be bent to small radii and this should be borne in mind when considering point of entry. In small buildings the cable run is kept as short as possible, terminating in a distribution board at the first convenient position. In these buildings the distribution board will be fitted with a seal box to prevent moisture from entering the insulation of the service cable, a main fuse for the premises in a box sealed by the supply authority and the consumer unit or other switch and fuse gear belonging to the building. The position chosen for the distribution board should be readily accessible both for meter reading and for replacing fuses. 5 Lecturer: Bayan A.Taha  Electrical House Wiring Electrical Wiring: House electrical wiring is a process of connecting different accessories for the distribution of electrical energy from the supplier to various appliances and equipment at home like television, lamps, air conditioners, etc. Insulated electrical wires will be taken out to various places in the premises to supply power to different type of loads like lights , fans , refrigerators , room coolers , heaters, etc. There are different types of electrical wiring that are used in domestic properties. Lecturer: Bayan A.Taha 6 Points to be considered for selection of wiring 1. Initial cost: It should be economical. 2. Durability: It must be able to withstand wear and tear due to weather. 3. Safety from fire: It should be free from risk of fire as far as possible. 4. Mechanical protection: It must provide mechanical protection to the cables. 5. Permanency : The wiring must not be affected by the action of weather, fumes, dampness, chemical etc. 6. Appearance: The appearance should be good enough to view. 7. Accessibility: It should be easy to extend or repair the wiring. 8. Life: The system should have good life time. 9. Maintenance cost: It should be low. Lecturer: Bayan A.Taha 7 Wiring types according to need Wiring Domestic wiring Commercial wiring Industrial wiring Lecturer: Bayan A.Taha 8 Cleat wiring 1. Very simple method and cheapest one. 2. Single core PVC cables are used in this system. 3. Cleats are made up of porcelain and have two parts base piece and cap. 4. It is a temporary system, therefore making it unsuitable for domestic premises. 5. this system is not used in damp walls, ceilings. 6. Its life time is approximately 5 years. Lecturer: Bayan A.Taha 9  Wooden Casing and Capping wiring 1. The casing consists of V-shaped grooves (usually two to hold the cables of opposite polarity in different groves). 2. It is covered at the top by means of rectangular strip of wood, known as capping of same width as that of casing. 3. The cables used in this type of wiring are either VIR or PVC or any approved insulated cables. Lecturer: Bayan A.Taha 10 Cab Tyre Sheaths(CTS) or Tough Rubber Sheath(TRS) or PVC Sheath or Batten wiring 1. Insulated wires are run through the straight teak wooden battens. 2. The wooden battens are fixed on the ceiling or walls by plugs and screws. 3. The cables are fitted onto the battens by using tinned brass link clips. 4. These clips are fixed to the battens with rust-resistance nails. 5. This wiring installation is simple and cheap. 6. This system takes less time to install. 7. These are mainly used for indoor installations Lecturer: Bayan A.Taha 11  Conduit wiring 1. Conduit wiring is a system where the cables are enclosed in metal or plastic tubes. 2. The conductors have insulation which is rated at the voltage required but gives no mechanical protection. 3. Concealed wiring is the most popular and common method of wiring the residential buildings. 4. This method is the safest method of wiring and also look beautiful. 12 Lecturer: Bayan A.Taha Conduit wiring Advantages 1. Conduit provides protection against mechanical injury and fire & is shock proof. 2. Conduit provides protection against chemicals. 3. The whole system is water proof. 4. Conductors are safety secured from moisture. 5. This wiring has far better look. 6. It has a longer life. Disadvantages 7. It is costly system of wiring 8. It requires more time for erection 9. It requires highly skilled labour 13 Lecturer: Bayan A.Taha  Technical Terms Related To Wiring Fuse is a thin piece of wire with low melting point connected at its end in a fuse plug. The function of fuse wire is to protect the electrical appliances from heavy current. It also known as cut out. Types of Fuse Rewirable Fuses (Semi Enclosed) Cartridge Fuse (Totally enclosed) Types of Fuse Rewritable Fusses Cartridge Fuse (Semi Enclosed) (Totally Enclosed) 14 Lecturer: Bayan A.Taha  Miniature Circuit Breaker Miniature Circuit Breaker MCB is a device that is used to break the circuit at the time of excess of current and protects the device from the appliances from the damage. The MCB has some advantages compared to fuse.  It automatically switches off the electrical circuit during abnormal condition of the network means in over load condition as well as faulty condition. The fuse does not sense but miniature circuit breaker does it in more reliable way. MCB is much more sensitive to over current than fuse.  Quick restoration of supply can not be possible in case of fuse as because fuses have to be Re-wirable or replaced for restoring the supply. But in the case of MCB, quick restoration is possible by just switching on operation. 15 Lecturer: Bayan A.Taha Distribution Board Distribution board (also known as panel-board or breaker panel) is a component of an electricity supply system which divides an electrical power feed into subsidiary circuits, while providing a protective fuse or circuit breaker for each circuit in a common enclosure. 16 Lecturer: Bayan A.Taha  Electrical Accessories  Switch is used to make or break the electric circuit. Or it is used to switch “ON or OFF” the electric supply. The switches may be one-way switch and two-way switch. The one-way switch is used to control single circuit or lamp, where as the two-way switch is used to divert the flow of current to either of two directions. (for example, a light switch or a keyboard button) 17 Lecturer: Bayan A.Taha  Electrical Accessories  Lamp Holder the name indicates, a lamp holder is used to hold the lamp, and connect it electrically to supply terminals, required for lighting purpose. The lamp holders may be bayonet cap and screw type. Depending upon our requirement, these lamp holders are also manufactured in different designs Batten Lamp Holder ,Pendant Holder ,Angle lamp holder. Batten Lamp Holder Pendant Holder Angle lamp holder 18 Lecturer: Bayan A.Taha  Electrical Accessories  SOCKETS : A socket (also known as a receptacle or outlet) is fixed in place, often on the internal walls of buildings, and is connected to an electrical circuit  Plug: Plug is used to gain power from socket outlet and connect the circuits of instrument. These plugs normally of 5A and 15 A. 19 Lecturer: Bayan A.Taha  Lighting is an essential component in building design and functionality. It influences the mood, efficiency, and safety of spaces. In this assignment, you are required to research and write about the types of lighting In your write-up, ensure to: Include definitions and key characteristics of each lighting type. Explain the importance of lighting in creating a functional and pleasant environment. Lecturer: Bayan A.Taha 20