This website uses cookies to ensure you have the best experience. Learn more

Cables Over Head Essay

2076 words - 9 pages

Design specification
High voltage overhead power lines must comply with several requirements. We need to consider various factors for the design specification, mechanical and electrical and also the sites where the cables will be fixed.

The site is very important because its span varies enormously depending on the nature of the terrain and climate. Also important to the requirements are the lowest electrical resistance (to cut down losses), safe clearance over the ground, adequate strength for the applied loads, good mechanical strength able to manage the stresses and weights involved and convenient cost for the 100 or 1000 of km the lines regularly installed.

It is vital that ...view middle of the document...

.
Numerous other electrical, mechanical and structural applications of aluminium in electrical industries developed along with the growth of aluminium wire and cable.

Wire and Cable

The positive attributes of aluminium for electrical applications are: reasonably high electrical and thermal conductivities, low density, nonmagnetic properties, ease of drawing down to the smaller wire sizes and high resistance to weathering.
Because of technological advances and good price as compared to copper, there has been permanent expansion in the volume, sizes and varieties of aluminium conductors.

Aluminium Conductor Materials
It was early learned that the electrical resistivity of aluminium is markedly increased by impurities; electrical conductor grade (EC) metal, containing approximately 99.5% Al, was established for most conductor uses. At present,
WHY ALUMINIUM?
The utilisation of aluminium has increased quickly since World War II, in no doubt by the change in the aluminium-copper price relationship. Aluminium has over twice the conductivity of copper on a weight basis, and aluminium conductor is used for almost all overhead sub transmission and distribution lines.

There are some great reasons because in numerous countries aluminium has taken the place of copper for main conductor material of all components of the transmission and distribution systems.
Aluminium is much lighter than copper. The density of aluminium is about 30 % that of copper. Especially in overhead line construction this factor is very important because heavy conductors lead to heavy and expensive pole structures. Handling and transportation of aluminium conductors and cables are also easier compared with heavy copper conductors and cables. The lightness of aluminium gives advantages in many ways
Aluminium is the most common metal in the earth surface - its amount is about 8 %. Today copper are limited and diminishing so the price of copper has been high and rising. The price of aluminium was low and rather steady state for years, but some rising can be noticed in it, too. Because of lightness of aluminium, the price of aluminium conductors and cables are clearly smaller than those of copper conductors and cables.
Long-distance overhead conductors use aluminium in first choice to copper - the inferior electrical conductivity being more than compensated by the lower density and cost. In composite steel-Al Cables, the steel carries largely or all of the mechanical load, and the Al the electrical current. Aluminium is frequently now used throughout, serving both electrical and mechanical purposes.

Aluminium is about a third the weight than equal volume of copper, steel or brass.
Aluminium can supported heavy loads and heavy pressures.
The strength when alloyed approaches that of steel.
Corrosion resistance - The creation of a microscopic film of aluminium oxide on the surface of the metal protects it against corrosion and also makes a good insulation.

...

Other Papers Like Cables over- Head

Level 1 Award in Health and Safety

4829 words - 20 pages hazard and risk of each item listed in the table below. Item | Hazard | Risk | Trailing Leads | Tripping up and falling | Fractures to feet and hands, bruising, cuts toarms | Dropping tools and debris | Head injury | Someone working underneath can come in contact and break their head. | Stability of ladders | Fall from above | Person working can fall from above ladders and can get injuries. | Overhead cables | Flashover or Electrical

Matrix V Allegory of the Cave

745 words - 3 pages , 514AI-518D8 ). Descartes, “suppose we are dreaming, that all these particulars namely, the opening of the eyes, the motion of the head, the putting fourth of the hands or merely illusion” (Descartes, Meditation on First Philosophy, 1641). The Matrix, complain that computer system has taken over the entire human race and control their minds and keep their brain connected via cable” Synopsis, The Matrix, 1999). The two with the most differences

Motorola

2561 words - 11 pages Since it first eSince it first entered the competitive electronic firm market, Motorola has continued to remain successfully as a world leader in mobile communication technology, ranking as the leading maker of cellular telephones, paging devices, automotive semi-conductors, and microchips that are used to operate devices other than computers. Although it has lost a few battles, Motorola has taken on the Japanese head to head, through these

Critical Analysis of Golding’s Use of Tone in Lord of the Flies

1345 words - 6 pages tone. The conch comes to symbolize authority, democracy and order. Upon the mentioning Piggy's glasses, images of insight and reason come to mind. With this highly connotative language, Golding creates many contrasts as well to convey his underlying theme. He compares the dazzling beach's "pink granite" [Page 12], green feathered palm trees and endless sand [Page 10] to the "darkness of the forest", full of "broken trunks", "cables of creepers

Health & Safety Unit 304 Stils

1179 words - 5 pages ) Daily Classroom Health & Safety Checklist | ✓ | Trailing cables avoided | ✓ | Pre-use checks carried out on all electrical equipment | ✓ | Fire exit doors not sticking and all exit signage in place | ✓ | Fire extinguisher in place and fixing to wall (where appropriate) | ✓ | Finger guards on doors are undamaged | ✓ | Nothing has been put on top of, in front of or closely adjacent to the heater | ✓ | Clear access

Test Saoundbuzz

4530 words - 19 pages , Sales, Marketing, Human Resources, Research & Development, Engineering, Quality, Estimating, and Accounting, among others. Demand Flow Manufacturing techniques concentrate in: * * * * Process design Material turn-over Minimal over-head support costs Quality of the assembled products DBI Sala started to implement DFT approximately since May 2001. Even though the company is trying to implement DFT in all the departments, this study will

Comprehensive Classroom Technology Plan

4735 words - 19 pages for students as they head off to college preparing them for the continued potential dangers of the internet (McQuade III. 2007). Teachers must start educating our students from day one on the safety of the internet and continue until they graduate. Having a technology in the classroom is a benefit for everyone. Teachers will be able to work with students more and spend less time worrying about how they are going to compute students

The World Is Flat

1783 words - 8 pages cheerleader for globalization, building upon his 1999 The Lexus and the Olive Tree. Like its predecessor, this book showcases Friedman's gift for lucid dissections of abstruse economic phenomena, his teacher's head, his preacher's heart, his genius for trend-spotting and his sometimes maddening inability to take himself out of the frame. It also shares some of the earlier volume's excitement (mirroring Rajesh Rao's) and hesitations about whether

Network Security

1846 words - 8 pages A 5 page paper on network security with 5 references NETWORK SECURITY Let us go back, twelve years. Where's Internet? Concentrated in the cables that connect the offices and cubicles of the American ministry of defense. Things were simple, and despite the sensitive nature of the data transferred no body talked about net work security, no body knew what was to follow. Some how a revolution was triggered, the information net burst out of its

Coarse Screen for Stp

1386 words - 6 pages to the screening discharge point in the head section. The wetted parts of cleaning rakes shall be fabricated in Stainless Steel. The rake tines shall be replaceable and bolted to the rake carriage and shall mesh with the bar screen openings. The rake assembly shall be supported by cast iron sliding blocks and shall slide in stainless steel rolled section channel guides recessed in the side walls / anchored to the side walls. The discharge

The Statue of Liberty

2234 words - 9 pages assembly of the statue and pedestal was held. The President, Grover Cleveland, accepted the statue along with the nation by stating, "We will not forget that liberty here made her home; nor shall her chosen alter by neglected". One million people looked at it while being brought to the New York Harbor. The sculptor pulled the cord to remove the French tricolor from her face. On 1877, the right arm was raised on Madison Square in New York. The head

Related Essays

Telecommunications Essay

1764 words - 8 pages , fiber-optic cables, and wireless technology. A headend is the facility that houses the receiving antennas and combines broadcasts from local TV stations and premium cable providers and sends them out on a single cable known as a trunk cable. The feeder cable is the cable which runs from the head end to the trunk amplifier and may terminate at a network access point or local convergence point. Drop cables run from the network access point to

What Is Virtual Reality? Essay

887 words - 4 pages system is based on a Commodore Amiga with some added hardware and software. A version of the Mandala is used by the cable TV channel Nickelodeon for a game show (Nick Arcade) to put the contestants into what appears to be a large video game. 3.3. Immersive Systems The ultimate VR systems completely immerse the user's personal viewpoint inside the virtual world. These "immersive" VR systems are often equipped with a Head Mounted Display

Nelson Mandela Electricity Department: A Case Study

5441 words - 22 pages NELSON MANDELA METROPOLITAN ELECTRICITY & ENERGY DEPARTMENT A CASE STUDY It was an “Initiation” management committee meeting for Jack Simons, the newly appointed General Manager (GM) for the Electricity & Energy Department at Nelson Mandela Metropolitan Municipality. He was recruited from Eskom just over three months ago. He was replacing Piet Volsoo who opted for an early retirement after 17 years with the Municipality. Management

Wireless Network Connections Essay

2815 words - 12 pages and mostly inexpensive. Very soon wireless networking may be available from just about anywhere and at any time. Bluetooth is a universal wireless standard for connecting various digital devices. Bluetooth is simply a way to connect devices to one another without the use of cables that transmits the signal over short distances. Bluetooth is “cable elimination technology”. Wireless Connections What is Wireless? Wireless communication is the