types of cables .pptx

Cable Types

1. WORKSHOP PRACTICE Electric shop Types of cables Dr. Aneela Wakeel 1

2. A cable is most often two or more wires running side by side and bonded, twisted, or braided together to form a single assembly, but can also refer to a heavy strong rope. 2

3. Main cable components An electric cable is made up of a conductor, which channels the electricity flow, and an insulation that contains this electricity flow in the conductor. Moreover, other auxiliary elements can be included which ensure its longevity. The conductor is where the electric current is actually transmitted, with copper being generally the most used material. The insulation is the layer of polymer, plastic or elastomer which surrounds the conductor and insulates it from external contact. 3

4. Insulation Color Code To enable wires to be easily and safely identified, all common wiring safety codes mandate a color scheme for the insulation on power conductors. In a typical electrical code, some color-coding is mandatory, while some may be optional. Many local rules and exceptions exist. Older installations vary in color codes, and colors may shift with insulation exposure to heat, light, and aging. Many electrical codes now recognize (or even require) the use of wire covered with green insulation, additionally marked with a prominent yellow stripe, for safety grounding (earthing) connections. This growing international standard was adopted for its distinctive appearance, to reduce the likelihood of dangerous confusion of safety grounding wires with other electrical functions, especially by persons affected by red-green color blindness. 4

5. PROPERTIES Electric Properties: - dielectric strength - insulation resistance - insulation power factors Mechanical Properties: - toughness and flexibility - tensile, elongation and crushing strengths - resistance to abrasion or moisture Brittleness Chemical Properties: - moisture absorption - resistance to oil, gas, acids and alkalis stability when exposed to sunlight, ozone, or flames Thermal Properties: - expansion and contraction - softening and flow temperature - compatibility with operating, ambient, or emergency overload and short circuit conditions 5

6. CONDUCTOR MATERIALS Copper The principal electrical conductor due to its excellent conductivity and reasonable cost. Aluminum 61% the conductivity and .3027 times the weight of copper. Used in power cables, overhead (ACSR), and some building wire. Copper weld A thin coating of copper fused to a steel core. Used in line wire, cable messengers and stranded with copper for strength or extending flex life. Alum weld A thin coating of aluminum fused to a steel core. Used in line wire and cable messengers. Tinsel Flat ribbons of bronze, silver, or copper alloy spiraled around a textile core of cotton, nylon, etc. Used in telephone and electronics applications as conductors in line cords, microphone cords. Thermocouple Special matched Alloy Conductors. Used in temperature measuring applications 6

7. TYPES OF CABLES Coaxial Cable: Coaxial cable is made up of a copper conductor surrounded by a layer of flexible insulation.  The center conductor can also be made of tin plated aluminum cable allowing for the cable to be manufactured inexpensively. Over this insulating material is a woven copper braid or metallic foil that acts as the second wire in the circuit and as a shield for the inner conductor. This second layer, or shield also reduces the amount of outside electromagnetic interference. Covering this shield is the cable jacket.  Cable television uses coaxial cable. 7

8. TYPES OF CABLES Shielded Twisted Pair : STP cable uses cancellation, shielding, and twisted wires.  The twisted wires and shielded twisted-pair cables allow for more cancellation of electrical interference than the unshielded twisted-pair cables.  Each pair of wires is wrapped in metallic foil and those four pairs of wires are wrapped in an overall metallic foil. 8

9. TYPES OF CABLES Unshielded Twisted Pair : UTP  is a four-pair wire medium used in a variety of networks. Each of the eight copper wires in the UTP cable is covered by insulating material. In addition, each pair of wires is twisted around each other. This type of cable relies on the cancellation effect produced by the twisted wire pairs to limit attenuation caused by electromagnetic interference and radio frequency interference.  9

10. 600V SINGLE CONDUCTOR CABLE It consists of an insulation ,magnetic shield and rubber jacket. Many thin conductors are kept together which acts like a single conductor. 10

11. ARMORED CABLE Steel wire armored cable , commonly abbreviated as SWA, is a hard-wearing power cable designed for the supply of mains electricity. 11

12. CONTROL CABLE Control Cable  is a flexible instrumentation cable designed for measuring, control or regulation in the field of process automation. It is a highly flexible multicore cable, with (class 5) copper conductors and a  galvanised steel wire braid (GSWB) for mechanical protection. The cable is typically manufactured with PVC insulation, bedding and a transparent PVC sheath. The transparent sheath means signs of deterioration, damage or corrosion can be detected with ease. 12

13. COPPER CABLE Copper wire is used in  power generation ,  power transmission , power distribution ,  telecommunications ,  electronics  circuitry 13

14. LOW VOLT INDUSTRIAL CABLE These cables are generally used in low voltage applications in industry. It is used in industrial wiring. 14

15. POWER CABLE These cables are used to transmit electricity from power station to consumers over long distances. Overhead lines use this type of cables. 15

16. MEDIUM VOLTAGE POWER CABLE These cables are used in medium voltage applications like supply cables in a residential area. 16

17. SHIELDING POWER CABLE A  shielded cable  is an electrical  cable  of one or more insulated conductors enclosed by a common conductive layer. The  shield  may be composed of braided strands of copper (or other metal, such as aluminium ), a non-braided spiral winding of copper tape, or a layer of conducting polymer. 17

18. PORTABLE CABLE Portable cable is a  cable  with multiple  conductors  used for functions requiring flexibility. The cord can be employed for power in a range of applications, such as operating  motors  in small and large tools, equipment, power extensions,  home appliances  and  machinery . Portable cords may be used in commercial, industrial and residential applications. They work well on job sites where resistance to  oil , chemicals and  abrasion  is vital and also perform well in extreme environments - both the heat and the cold, outside or inside. 18

19. TELEPHONE CABLE As the name suggests it used in telephones. It consists of a thin copper conductor surrounded by insulation. One telephone cable contains three to four of these conductors. 19

20. thermocouple A Thermocouple is a device used for the measurement of temperature. It can be even considered as a sensor for the measurement of temperature. The device consists of two dissimilar metals or semiconductors that contact each other in one are more points. The junction in most of the cases are welded. 20

21. Temperature is measured mostly at welded region. One end is connected to the region where the temperature is to be measured. This end considered as the hot region or the measuring region. The end is connected to the body of known temperature. This end is considered as cold region or the reference junction. Thus the thermocouple measures the temperature of the known region with respect to the known junction 21 GOVERNING EFFECTS The main principles that governs the operation of thermocouple are  SEEBECK EFFECT  PELTIER EFFECT

22. SEEBECK EFECT The Seebeck effect states that when two different or unlike metals are joined together at two junctions, an electromotive force (emf) is generated at the two junctions. The amount of emf generated is different for different combinations of the metals. 22

23. PELTIER EFFECT As per the Peltier effect, when two dissimilar metals are joined together to form two junctions, emf is generated within the circuit due to the different temperatures of the two junctions of the circuit. 23

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25. TYPES OF THERMOCOUPLES  TYPE E  TYPE J  TYPE K  TYPE M  TYPE N  TYPE T  TYPE B  TYPE R  TYPE S 25

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28. TYPE-K Type K thermocouples usually work in most applications as they are nickel based and exhibit good corrosion resistance. It is the most common sensor calibration type providing the widest operating temperature range. This type of thermocouple should be protected with a suitable metal or ceramic protection tube, especially in reducing atmospheres. In oxidizing atmospheres, such as electric furnaces, tube protection is not always necessary when other conditions are suitable; however, it is recommended for cleanliness and general mechanical protection. 28

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32. Fiber Optic Cable Fiber Optic Cable is also known as the Optical Fiber Cable. It is made up of plastic or glass. It transmits signals in the form of light. There are 3 basic components of the optical transmission system which are as follows: Light source Transmission media (fiber optics) Detector 32

33. FIBER OPTIC Data Carrier It carries data in the form of light. Bandwidth It offers higher bandwidth. Structure It is thin, lighter in weight and smaller in size. Environment It can be laid in different environment because it is more resistant to corrosive materials. Attenuation Attenuation is very low. Interface As in this data travel in the form of light, they are not affected by electrical and magnetic interface. COPPER CABLE Data Carrier It carries data in the form of electric signals. Bandwidth It offers lower bandwidth. Structure It is heavier and thicker. Environment It cannot be laid in different environment because it is more prone to corrosive materials. Attenuation Attenuation is high. Interface As in this data travel in the form of electric signals, they are affected by electrical and magnetic interface. 33