types of wiring.pptx

types of wiring

1. Electrical Wiring R.A.KIRUTHIKA III B.Sc.,PHYSICS ‘C’ 21.06.2021 SESSION 3

2. INTRODUCTION Electricity requires an electric path to flow and there are many conducting materials used for this purpose. There are many semi conducting materials which are used to reduce the voltage and also drop the current flow. There are non-conducting materials which are used as insulation during working on live-lines.

3. INTRODUCTION In this unit we will study how the household or industrial wiring is done and what materials are essential for household or industrial wiring. We will also study the different types of wiring and how they is done.

4. Electrical Wiring A process of connecting various accessories for distribution of electrical energy from supplier’s meter board to home appliances such as lamps, fans and other domestic appliances is known as Electrical Wiring . The wiring system selected will depend to a large extent on the types of service required.

5. Factors Affecting the Selection of Wiring Durability Safety Appearance Cost Accessibility Maintenance Cost

6. IDENTIFYING AND SELECTING THE WIRING MATERIALS AND COMPONENTS Wiring materials : Electrical wire is made of materials like copper, aluminium and silver. As silver is expensive, mostly copper and aluminium are used in wiring.

7. CLASSIFICATION OF MATERIALS Conducting materials Insulating materials Semiconductor materials

8. Conducting Material Copper It is a good conductor of electricity. It is used in wiring materials in cables. Its has low resistance and is used for conduction of electricity at high, medium and low voltage. It is used in wiring and cable making. ( b) Aluminium It is light weight and cheaper in comparison to copper. Therefore , this type of conducting material is mostly used in electrical wiring. It is silvery–white in colour and it has a soft texture. It is often used in wiring and making cable.

9. WIRING- Types of wiring according to the Uses. Domestic Wiring. Commercial Wiring. Industrial Wiring.

10. Types of Internal Wiring / DOMESTIC WIRING Cleat wiring Casing and capping wiring Batten wiring CTS or TRS or PVC sheath wiring Lead sheathed or metal sheathed wiring Conduit wiring Surface or open Conduit type Concealed or underground type Conduit

11. Cleat Wiring In this system of wiring, cables are supported and gripped between porcelain cleats and 6mm. above the wall or roof. The main part is base, which is grooved to accommodate the cables, the other part is the cap which is put over the base

12. Cleats are placed above the wall or roof at an interval of 30 to 60 cm. The cables recommended for this type of wiring are VIR or PVC cables and any other approved insulated cables. Advantages It is the cheapest system. Installation and dismantling is easy. Less skilled persons are required. Inspection is easy. Alterations and additions are easy.

13. Disadvantages It is purely temporary wiring system. Appearance is not good. Cables are exposed to atmosphere and there is a possibility of mechanical injury. Th i s sy s tem sh o u ld no t b e u sed i n damp places other wise insulation gets damaged.

14. Casing and Capping Wiring It cons i sts o f recta n g ula r block s m ade fr o m sea s oned and k n ots free w ood (pr e ferab l y te a k - wood). The casing has usually two (or three) ‘U’ shaped groov e s, into which t h e V I R o r PVC cables a r e laid in such a w ay t h at t h e o p p o s ite p olar i ty cables are laid in different grooves. The casing is covered by means of a rectangular strip of the same width as that of casing known as capping and is screwed to it. This system of wiring is suitable for low voltage installations.

15. Advantages It provides good insulation as conductors are apart. It provides good mechanical strength. Easy to inspect by opening the capping.

16. Disadvantages It is costly system now – a – days because it needs seasoned, knot free wood. There is every risk of fire. The l abor co s t i s m o re becaus e i t re quir e s skilled carpenters. This system can not be used in damp places.

17. Due to defects in woods and high cost of wood now a days P.V.C casing capping are used. These are cheaper in cost and esay to handle. The wiring look is also beautiful and no paint coating is required.

18. CTS or TRS or PVC Sheath Wiring CTS cab l es are av a ila b le in s ingl e - c o r e, twin - co r e or three-core with a circular or oval in shape. CT S cabl e s a r e su f fic i en tly c h e mica l p roof, water proof, steam proof. The cables are run or carried on well seasoned, perfectly straight and well varnished (on all four sides) teak wood batten of thickness 10 mm. at least. The width of the batten depends upon the number and size of cables to be carried by it. Battens are fixed to the walls or ceilings by means of gutties or wooden plugs. The cables are held on the wooden batten by means of tinned brass link clips spaced at an interval of 10 cm. .This system is suitable for low voltage installations..

19. Advantages It’s appearance is good, if carried properly. It’s life is sufficiently long. It can with s t a n d t he action of mos t chemicals such as acids and alkalies. It’ s inst a l l ation i s e asy and qu i ck compa r ed to casi n g - capping. It is cheap compared to casing – capping, metal conduit and lead sheathed wiring. Disadvantages This system of wiring is not recommended in situations exposed to sun and rain, unless preventive steps are taken. It can not be used in damp places. Good work man ship is required to make a sound job. Only suitable below then 250V.

20. Check Your Progress Wiring material is of three types __________, ____________ and ____________. Silver is a bad conductor of electricity.(TRUE/FLASE) PVC casing and capping are used for covering the wires . ( TRUE/FLASE)

21. THANK YOU