Grounding Transformers - Electrical Design, Transformer Design, and Distribution Transformer Design
Grounding is clearly one of the most important aspects of electrical design, but it steadfastly continues to be misinterpreted and misunderstood. Millions of dollars in liability and loss can be attributed to ground-fault arcing; thus, grounding-related issues should top the checklists of any electrical contractor.
Grounding Transformers:
Simply put, a grounding transformer is used to provide a ground path to either an ungrounded "Y" or a delta connected system. Grounding transformers are typically used to:
Provide a relatively low impedance path to ground, thereby maintaining the system neutral at or near ground potential Limit the magnitude of transient over voltages when re-striking ground faults occur Provide a source of ground fault current during line-to-ground faults Permit the connection of phase to neutral loads when desired
If a single line-to-ground fault occurs on an ungrounded or isolated system, no return path exists for the fault current, thus no current flows. The system will continue to operate but the other two un-faulted lines will rise in voltage by the square root of 3, resulting in overstressing of the transformer insulation and other associated components on the system by 173%. MOV lightning arresters are particularly susceptible to damage from heating by leakage across the blocks even if the voltage increase is not sufficient to flash over. A grounding transformer provides a ground path to prevent this.
Large multi-turbine wind farms provide an example of the use of grounding transformers for fault protection on ungrounded lines. In many wind farms the substation transformer provides the sole ground source for the distribution system. When a ground fault on a collector cable causes the substation circuit breaker for that cable to open, the wind turbine string becomes isolated from the ground source.
The turbines do not always detect this fault or the fact that the string is isolated and ungrounded; thus the generators continue to energize the collector cable, and the voltages between the un-faulted cables and the ground rise far above the normal voltage magnitude as described above. A grounding transformer placed on the turbine string provides a ground path in the event the string becomes isolated from the system ground.
Construction:
Grounding transformers are normally constructed either with
A ZigZag (Zn) connected winding with or without an auxiliary winding or As a Wye (Ynd) connected winding with a delta connected secondary that may or may not be used to supply auxiliary power
The geometry of the Zig-Zag connection is useful to limit circulation of third harmonics and can be used without a Delta connected winding or the 4- or 5-leg core design normally used for this purpose in distribution and power transformers. Eliminating the need for a secondary winding can make this option both less expensive and smaller than a comparable two-winding grounding transformer. Furthermore, use of a Zig-Zag transformer provides grounding with a smaller unit than a two-winding Wye-Delta transformer providing the same zero sequence impedance.
Wye connected grounding transformers, on the other hand, require either a delta connected secondary or the application of 4 or 5 leg core construction to provide a return flux path for unbalanced loading associated with this primary connection. Since it is often desirable to provide auxiliary power from the grounding transformer secondary winding, this benefit can sway the end user to specify a two-winding grounding transformer in lieu of a Zig-Zag connection. The current trend in wind farm designs is toward the Wye connected primary with a delta secondary.
It is important to understand that both Zig-Zag and two-winding grounding transformers can be provided with the ability to provide auxiliary power, and this can be either a Wye or Delta connected load.
A solidly grounded system using a grounding transformer offers many safety improvements over an ungrounded system. However, the ground transformer alone lacks the current limiting ability of a resistive grounding system. For this reason, neutral ground resistors are often used in conjunction with the grounding transformer to limit neutral ground fault current magnitude. Their ohm values should be specified to allow high enough ground fault current flow to permit reliable operation of the protective relaying equipment, but low enough to limit thermal damage.
How to Specify a Grounding Transformer
The basic parameters required for quoting a grounding transformer are:
Primary Voltage - This is the system voltage to which the grounded winding is to be connected. Don't forget to specify the BIL also. In some cases the BIL will be dictated by equipment considerations, such as 150 kV BIL ratings on 34500 volt wind farms because of the limitation on dead front connectors. Rated KVA - Because the grounding transformer is normally a short time device, its size and cost are less when compared with a continuous duty transformer of equal kVA rating. For this reason, grounding transformers are often not sized by "kVA" but by their continuous and short time current ratings. Regardless of how you rate it, the grounding transformer must be sized to carry the rated continuous primary phase current without exceeding its temperature limit. This load includes the magnetizing current of the core, the capacitive charging current for the cables, and any auxiliary load if applicable. The higher this value, the larger and more costly the transformer will be. Typical continuous current values can be as low as 5 amps to as high as a few hundred. Be sure to include any auxiliary loading requirements. Continuous Neutral Current - The continuous neutral current is defined as three times the phase to current, or in other words, the zero sequence current. This is usually considered to be zero if the system is balanced. However, for the purposes of designing a grounding transformer, it is a value that is expected to flow in the neutral circuit without tripping protective circuits (which would force the current to be zero) or the leakage current to ground that is not a symmetrical function. Again this value is needed to design for thermal capacity of the grounding transformer. Fault current and duration - This value is needed to calculate the short time heating that results from a fault on the system and should be determined from an engineered system study. Typical values for this range from a few hundred amps to a few thousand amps with duration times expressed in seconds and not cycles. For instance, a value of 400 amps for 10 seconds is typical. The fault duration is a critical parameter for the transformer designer. Where protection schemes use the grounding transformer for tripping functions, a relatively short time duration is specified (5 -10 seconds). On the other hand, a continuous or extended neutral fault current duration would be required when the grounding transformer is used in a ground fault alarm scheme. Impedance - The impedance can be expressed as a percentage or as an ohm value per phase. In either case it should be chosen so that the un-faulted phase voltages during a ground fault are within the temporary over-voltage capability of the transformer and associated equipment, such as arresters and terminal connectors. Because of this description, the values can vary from as low as 8% to almost 100%. This value must come from the system designer. Primary winding connection - Specify the type of primary connection, either Zig-Zag or grounded Wye. Secondary connection - specify the secondary voltage and connection when applicable. Specify the size of auxiliary loading to be connected for either Zn or Wye connected primary windings. If the option is to have a two winding transformer with no secondary load, advise if the delta winding can be "buried" (that is not brought out) or if only one bushing is to be brought out for grounding to the tank or testing.
· Basic overall construction features - note the following features as they apply to each transformer
· Compartmental Padmount transformer with integral tamperproof compartment or substation design
· Outdoor or indoor
· Fluid type- mineral oil, silicone, Envirotemp FR3
· Connectivity -dead front, live front, spade terminals, location of terminals - cover or sidewall , exposed or enclosed, etc
· Temperature rise is assumed to be 65'C
· Site elevation or environmental concerns
· Special paint as required
· Neutral Ground Resistors - The rated voltage of the NGR should be equal to the line to ground voltage of the grounding transformer. The current rating and duration should match the grounding transformer ratings. Remember to set the current rating high enough to be above the cable charging current and grounding transformer magnetizing current.
Grounding Transformers - Electrical Design, Transformer Design, and Distribution Transformer Design
Transformers Fall Of Cybertron Playthrough - Part 3
Video Clips. Duration : 14.92 Mins.
Transformers Fall Of Cybertron Playthrough - Part 3
Here Is The Link To Part 4: www.youtube.com Also it would be grate if you liked and subscribed to my channel! Hello and welcome to my playthrough of transformers fall of Cybertron Part 3 with Live Commentary. I hope you enjoy the video. Subscribe To My Channel: full.sc Come and follow me on Twitter for News, Updates and More: twitter.com Fall of Cybertron starts the game off 6 days after the events of leaving Cybertron towards a portal where the Autobots can escape Cybertron from the Decepticons. The first level consists of Bumblebee going on side missions to protect the Ark and Optimus Prime. The game then returns to the past 6 days before the Ark battles the Nemesis. Developers: High Moon Studios Publisher: Activision Also Watch in HD for the best viewing experience. Remember To Comment Thumbs Up And Subscription Is Very Appreciated
Transformers Fall Of Cybertron Playthrough - Part 3
Transformers Fall Of Cybertron Playthrough - Part 3
Transformers Fall Of Cybertron Playthrough - Part 3
Transformers Fall Of Cybertron Playthrough - Part 3
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10 Famous Celebrities Wearing Green Contact Lenses!
It's true- green contact lenses are found by some of our favourite Hollywood celebrities. Ever since green contacts started becoming more fashionable amongst Asian young girls, these gorgeous and beautiful Hollywood celebs have noticed how powerful the effect of green contact lenses are.
1. Tyra Banks
This former supermodel and TV host is famous for facial characteristics and her eyes that smile. Her eyes constantly change color, her own natural color is a kind of greenish-brown. You will also see them to be a purer hue of green which is not her natural color but comes from green contact lenses.
2. Katie Holmes
The actress Katie Holmes was born in the place Toledo Ohio. She has dated Joshua Jackson but married the handsome actor Tom Cruise. Katie has naturally brown hair color and brown eyes. She often wears colored contacts but green colored lenses are her favourite.
3. Lindsay Lohan
Lindsay Lohan is an actress, pop singer and model. Lindsay is a star to many and a favourite target of the paparazzi. She likes to shake things up once in a while by changing her already natural green eyes to a more intense fierce green color.
4. Jennifer Garner
Wears green contact lenses in Elektra and Daredevil. Even though the Elektra in the comic book has got brown eyes, which is the natural eye color of Jennifer.
5. Rachel McAdams
Rachel McAdams grew up in St. Thomas, Ontario. At the age of 13, she was performing in Shakespearean plays in summer theatre camp. She looks beautiful with green colored contact lenses.
6. Mila Kunis
She is also known for playing Jackie Burkhart in the popular "That 70's Show". Mila is often spotted with green contact lenses. Her breakthrough movie was "Forgetting Sarah Marshall".
7. Pamela Anderson
She has been discovered at a British Columbia Lions football game that Pamela attended. She worn a Labatt's Beer T-shirt and her image was shown on the stadium's big screen. The fans cheered to this beautiful bombshell. She has naturally blue eyes but loves to wear green contact.
8. Shia LaBeouf
Shia Saide LaBeouf is an US actor, comedian and voice actor. LaBeouf played as Sam Witwicky in the Transformers sequel Transformers: Transformers: Revenge of the Fallen. He likes to wear green contacts to make is boyish look more sexy.
9. Jennifer Aniston
Jennifer Aniston is gorgeous. That does not stop her from being fashionably inventive with her looks. She has naturally brown eyes but she is often seen with a set of green eyes. This is thought of to be her favourite eye color, but of course come from green contact lenses.
10. Penelope Cruz
The Latinacelebrity Penelope Cruz is also a big fan of green colored lenses. She was born with naturally gorgeous brown eyes. But sometimes she likes to have fun with green contact lenses, combined with sexy and interesting ensembles.
I could go on and on and on, but the bottom line is this: seeing celebrities put on a set of green colored contacts, you know these will be the latest fashion trend.
10 Famous Celebrities Wearing Green Contact Lenses!
Transformers: Fall of Cybertron - Chapter 5: Cut and Run Pt. 1
Video Clips. Duration : 17.10 Mins.
Transformers: Fall of Cybertron - Chapter 5: Cut and Run Pt. 1
Please read the description. Be sure to like, comment and fave. *** Facebook: facebook.com Twitter: twitter.com Formspring: formspring.me *** Transformers: Fall of Cybertron Chapter 5: Cut and Run Pt. 1 Now we begin the fifth chapter and we play as everyone's favorite Autobot that can pack a sweet ride... Jazz. Groovy! *** Recorded using Hauppauge HD PVR Edited using ArcSoft ShowBiz and Sony Vegas 10
Transformers: Fall of Cybertron - Chapter 5: Cut and Run Pt. 1
Transformers: Fall of Cybertron - Chapter 5: Cut and Run Pt. 1
Transformers: Fall of Cybertron - Chapter 5: Cut and Run Pt. 1
Transformers: Fall of Cybertron - Chapter 5: Cut and Run Pt. 1
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Choosing Right Transformer For Mining Industry
Introduction
The US has one of the largest mining industries in the world - an industry closely linked with the economy. In the past, the discovery of resources such as gold and oil resulted in a major population shift and rapid growth for formerly remote regions of the country, such as California, Texas, and Alaska. Extraction of these resources, and finding new deposits, continues to provide the foundation for local economies in some regions.
Some of the minerals mined in the US are coal, uranium, copper, gold, silver, iron, lead, zinc and others. Most of the mines in the US are highly automated and thus energy intensive. To provide an example, even in the last decade of the 20th century, iron ore mining alone consumed 62.3 trillion Btu of energy across a calendar year. Because mining is such a large industry and makes a sizable contribution to the national income, mines must have a dependable source of power - a crucial resource for mining processes.
The mining and mineral extraction sector both in the US and worldwide relies heavily on energy to harness natural resources such as aggregates, precious metals, iron ore, oil, gas, and coal. This energy is used to power shovels and drills for excavating these products, loading them into enormous mining trucks or onto conveyer belts, sorting, sifting and crushing ores, heating, and a hundred other functions. Both surface and underground mining operations rely on powered equipment to extract materials and load trucks. Overall, the mining sector could not flourish without the use of vast amounts of energy.
The Role of Transformers
Mine 'Power Centers' or 'Load Centers' are an essential system for underground and surface mining. Their primary function is to convert distribution voltage into utilization voltage for equipment operation, thus placing power transformers at the heart of the load center. Proper selection of transformers is imperative, and must fulfill safety, reliability, and efficiency requirements. Determining capacity rating is among the first steps for selection of a power transformer for a mining load center. A rule of thumb here is to allow 1 kVA for every horsepower of connected load. Most mining processes, however, do not produce constant loads - all machinery is not connected all the time - and therefore the 1 kVA per horsepower thumb rule will typically result in transformer oversizing. According to the SME Mining Engineering Handbook by Howard L. Hartmann, "Past experience and demand factors established by manufacturers and operators, along with the horsepower of the connected load, are essential for determining transformer capacity. For typical underground mining sections, the kVA rating may lie within the range of 50 to 80% of the connected horsepower."
Transformer Losses
Standard transformers while under full load operate at 90 to 95% efficiency, with this figure dropping as the load lightens. This is due to inefficiencies in the transformer's core, a main component of the transformer. The losses in the core remain the same throughout the transformer's operating range. At 100% load, the amount of comparative loss is negligible. However, at reduced loads, the same amount of energy loss represents a higher percentage of energy being wasted. Unfortunately, average transformer loads run between 34 and 50% of the transformer's total capacity. With the majority of the electricity used
in the US being run through transformers at these lower loads, massive amounts of energy are being wasted. This issue is of special relevance to the mining industry, simply because of its high energy usage. Mining operations also involve hostile environments full of dust, dirt, chemicals, moisture and airborne contaminants. Load center transformers need to function reliably and efficiently in these environments over a long term.
Without electric power at mining facilities, the natural materials extracted from the earth in the mining process would be much more costly than they are today. Thus, power transformers provide a lot of muscle, capacity, and stability to an essential industry. From drilling trenches to busting up rock, carting out huge loads of materials and pulling up heavy amounts of minerals, power transformers provide the strength and capability needed.
Liquid Filled and Dry Transformers: Performance Characteristics
1.Liquid-Filled Transformers
While there is still debate on the relative advantages of the available types of transformers, there are some performance characteristics that have been accepted: • Liquid-filled transformers are more efficient, have greater overload capability and longer life expectancy. • Liquid-filled units are better at reducing hot-spot coil temperatures, but have higher risk of flammability than dry types. • Liquid-filled transformers sometimes require containment troughs to guard against fluid leaks. • Liquid filled transformers are smaller in size than dry-type units for the same power rating capacity and have lower losses because of their better thermal dissipation characteristics.
2.Dry Type Transformers
Dry type Transformers are usually used for lower ratings (the changeover point being 500kVA to 2.5MVA). They are usually placed indoors, serving an office building/apartment. Dry type units typically come in enclosures with louvers, or sealed.
Dry type transformers use almost no flammable materials and therefore do not constitute a fire hazard when used underground in both coal and other mines.
Dry type transformers in the mining industry are housed in a steel tank and the core and windings are cooled by air circulating within the tank, transferring heat to the steel tank which is in turn cooled by the external air. In some compact designs for mounting on mining machines water cooling is added to further improve the performance of the transformers.
Correct choice of insulating materials and an understanding of the cooling system is imperative if the transformer is to be correctly designed. For example, a temperature rise test conducted on a transformer manufactured and sold as continuously rated, can reveal that the transformer only had a continuous rating of 65% of the nameplate rating.
The Need for Energy-Efficient Mining
With the current focus on climate change and reduction of environmental impact, government agencies around the world are making increasingly stringent demands on industries to reduce energy consumption and manage waste more effectively, among others. It is surprising how many mining operations still use twenty-year-old technology.
Regulatory pressures are already beginning to affect the mining industry - according to an article on 'US Environmental Regulations and the Mining Industry' on the International Development Research Center (IDRC) website, "Environmental regulations have had an effect on the US mining industry's profitability. Companies have been forced to retrofit or renovate installations or leave the market. Increasing operational costs have affected their international competitiveness, and to some extent, this may be changing the world allocation of mining investment. Employment levels have fallen substantially, and local economies have borne part of this cost."
Mining companies in the US are thus feeling the pressing need to be energy-efficient, simply to stay competitive. Reducing energy consumption by adopting customized, cost-effective solutions like NEMA-approved transformers and harnessing solar or wind energy to meet their future energy needs can be good ideas in the long run, especially since the alternate energy option will help mining companies keep away from fluctuating international fuel prices. Alternate sources of energy are still a very small blip on the graph, in terms of actual power provided for industries like mining, and thus the sector as a whole needs to come up with more immediate ways to conserve energy.
Various types of transformers for the mining industry:
Transformers can be used in various open pit and hard rock (subterranean) applications that range from auxiliary lighting loads to power for cranes, drag lines, conveyor belts and other miscellaneous dedicated variable speed drive applications.
Benefits of energy-efficient mining
• Reduced cost of production
• Opening up of new reserves for Conclusion
On one hand the mining industry is all set to grow to keep up with increasing demand; on the other it has to stay competitive as fuel prices zoom upwards. For an energy intensive industry, keeping a check on fuel consumption and cost is critical. Thus the mining industry as a whole is looking for energy efficient technology, including power transformers.
Choosing Right Transformer For Mining Industry
Transformers: Fall of Cybertron - Chapter 10: The Final Countdown Pt. 2
Tube. Duration : 15.38 Mins.
Transformers: Fall of Cybertron - Chapter 10: The Final Countdown Pt. 2
Please read the description. Be sure to like, comment and fave. *** Facebook: facebook.com Twitter: twitter.com Formspring: formspring.me *** Transformers: Fall of Cybertron Chapter 10: The Final Countdown Pt. 2 Here's the 2nd part. Looks like we're closer to reaching Trypticon and boy, the Autobots really love getting blasted. *** Recorded using Hauppauge HD PVR Edited using ArcSoft ShowBiz and Sony Vegas 10
Transformers: Fall of Cybertron - Chapter 10: The Final Countdown Pt. 2
Transformers: Fall of Cybertron - Chapter 10: The Final Countdown Pt. 2
Transformers: Fall of Cybertron - Chapter 10: The Final Countdown Pt. 2
Transformers: Fall of Cybertron - Chapter 10: The Final Countdown Pt. 2
No URL Transformers: Fall of Cybertron - Chapter 10: The Final Countdown Pt. 2
10 Famous Celebrities Wearing Green Contact Lenses!
It's true- green contact lenses are found by some of our favourite Hollywood celebrities. Ever since green contacts started becoming more fashionable amongst Asian young girls, these gorgeous and beautiful Hollywood celebs have noticed how powerful the effect of green contact lenses are.
1. Tyra Banks
This former supermodel and TV host is famous for facial characteristics and her eyes that smile. Her eyes constantly change color, her own natural color is a kind of greenish-brown. You will also see them to be a purer hue of green which is not her natural color but comes from green contact lenses.
2. Katie Holmes
The actress Katie Holmes was born in the place Toledo Ohio. She has dated Joshua Jackson but married the handsome actor Tom Cruise. Katie has naturally brown hair color and brown eyes. She often wears colored contacts but green colored lenses are her favourite.
3. Lindsay Lohan
Lindsay Lohan is an actress, pop singer and model. Lindsay is a star to many and a favourite target of the paparazzi. She likes to shake things up once in a while by changing her already natural green eyes to a more intense fierce green color.
4. Jennifer Garner
Wears green contact lenses in Elektra and Daredevil. Even though the Elektra in the comic book has got brown eyes, which is the natural eye color of Jennifer.
5. Rachel McAdams
Rachel McAdams grew up in St. Thomas, Ontario. At the age of 13, she was performing in Shakespearean plays in summer theatre camp. She looks beautiful with green colored contact lenses.
6. Mila Kunis
She is also known for playing Jackie Burkhart in the popular "That 70's Show". Mila is often spotted with green contact lenses. Her breakthrough movie was "Forgetting Sarah Marshall".
7. Pamela Anderson
She has been discovered at a British Columbia Lions football game that Pamela attended. She worn a Labatt's Beer T-shirt and her image was shown on the stadium's big screen. The fans cheered to this beautiful bombshell. She has naturally blue eyes but loves to wear green contact.
8. Shia LaBeouf
Shia Saide LaBeouf is an US actor, comedian and voice actor. LaBeouf played as Sam Witwicky in the Transformers sequel Transformers: Transformers: Revenge of the Fallen. He likes to wear green contacts to make is boyish look more sexy.
9. Jennifer Aniston
Jennifer Aniston is gorgeous. That does not stop her from being fashionably inventive with her looks. She has naturally brown eyes but she is often seen with a set of green eyes. This is thought of to be her favourite eye color, but of course come from green contact lenses.
10. Penelope Cruz
The Latinacelebrity Penelope Cruz is also a big fan of green colored lenses. She was born with naturally gorgeous brown eyes. But sometimes she likes to have fun with green contact lenses, combined with sexy and interesting ensembles.
I could go on and on and on, but the bottom line is this: seeing celebrities put on a set of green colored contacts, you know these will be the latest fashion trend.
10 Famous Celebrities Wearing Green Contact Lenses!
Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42
Tube. Duration : 7.00 Mins.
Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42
www.youtube.com Click here to watch Transformers: War for Cybertron - Hands On (In Depth Gameplay Overview)! Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42 Chris Lockey takes a look at High Moon Studio's spectacular new title Transformers: War for Cybertron. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Follow Machinima on Twitter! Machinima twitter.com Inside Gaming twitter.com Machinima Respawn twitter.com Machinima Entertainment, Technology, Culture twitter.com FOR MORE MACHINIMA, GO TO: www.youtube.com FOR MORE GAMEPLAY, GO TO: www.youtube.com FOR MORE SPORTS GAMEPLAY, GO TO: www.youtube.com FOR MORE TRAILERS, GO TO: www.youtube.com TAGS: Video Game Review VGR Chris Lockey yt:quality=high Transformers War for Cybertron of cibertron 027242252349 High Moon Studios robot transforming vehicles autobots deceptions beastwars robots in disguise
Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42
Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42
Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42
Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42
No URL Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42
www.youtube.com Click here to watch Transformers: War for Cybertron - Hands On (In Depth Gameplay Overview)! Transformers: War for Cybertron: Video Game Review - Chris Lockey (9/10) S02E42 Chris Lockey takes a look at High Moon Studio's spectacular new title Transformers: War for Cybertron. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Follow Machinima on Twitter! Machinima twitter.com Inside Gaming twitter.com Machinima Respawn twitter.com Machinima Entertainment, Technology, Culture twitter.com FOR MORE MACHINIMA, GO TO: www.youtube.com FOR MORE GAMEPLAY, GO TO: www.youtube.com FOR MORE SPORTS GAMEPLAY, GO TO: www.youtube.com FOR MORE TRAILERS, GO TO: www.youtube.com TAGS: Video Game Review VGR Chris Lockey yt:quality=high Transformers War for Cybertron of cibertron 027242252349 High Moon Studios robot transforming vehicles autobots deceptions beastwars robots in disguise
Keywords:
Transformers
10 Famous Celebrities Wearing Green Contact Lenses!
10 Famous Celebrities Wearing Green Contact Lenses!
10 Famous Celebrities Wearing Green Contact Lenses!
Please read the description. Be sure to like, comment and fave. *** Facebook: facebook.com Twitter: twitter.com Formspring: formspring.me *** Transformers: Fall of Cybertron Chapter 10: The Final Countdown Pt. 2 Here's the 2nd part. Looks like we're closer to reaching Trypticon and boy, the Autobots really love getting blasted. *** Recorded using Hauppauge HD PVR Edited using ArcSoft ShowBiz and Sony Vegas 10
Keywords:
Transformers
Choosing Right Transformer For Mining Industry
Transformers
Please read the description. Be sure to like, comment and fave. *** Facebook: facebook.com Twitter: twitter.com Formspring: formspring.me *** Transformers: Fall of Cybertron Chapter 5: Cut and Run Pt. 1 Now we begin the fifth chapter and we play as everyone's favorite Autobot that can pack a sweet ride... Jazz. Groovy! *** Recorded using Hauppauge HD PVR Edited using ArcSoft ShowBiz and Sony Vegas 10
Tags:
Transformers
10 Famous Celebrities Wearing Green Contact Lenses!
10 Famous Celebrities Wearing Green Contact Lenses!
10 Famous Celebrities Wearing Green Contact Lenses!
Here Is The Link To Part 4: www.youtube.com Also it would be grate if you liked and subscribed to my channel! Hello and welcome to my playthrough of transformers fall of Cybertron Part 3 with Live Commentary. I hope you enjoy the video. Subscribe To My Channel: full.sc Come and follow me on Twitter for News, Updates and More: twitter.com Fall of Cybertron starts the game off 6 days after the events of leaving Cybertron towards a portal where the Autobots can escape Cybertron from the Decepticons. The first level consists of Bumblebee going on side missions to protect the Ark and Optimus Prime. The game then returns to the past 6 days before the Ark battles the Nemesis. Developers: High Moon Studios Publisher: Activision Also Watch in HD for the best viewing experience. Remember To Comment Thumbs Up And Subscription Is Very Appreciated
Keywords:
Transformers
Grounding Transformers - Electrical Design, Transformer Design, and Distribution Transformer Design
Transformers
MCDONALDS TRANSFORMERS PRIME HAPPY MEAL TOYS - 2012 FULL SET REVIEW
MCDONALDS TRANSFORMERS PRIME HAPPY MEAL TOYS - 2012 FULL SET REVIEW
Video Clips. Duration : 6.60 Mins.
MCDONALDS TRANSFORMERS PRIME HAPPY MEAL TOYS - 2012 FULL SET REVIEW
FULL SET OF THE MCDONALDS HAPPY MEAL TRANSFORMERS PRIME TOYS. OPTIMUS PRIME, MEGATRON, BUMBLEBEE, STARSCREAM, BULKHEAD, BREAKDOWN, RATCHET, AND KNOCKOUT! Opening theme by DrewsiferxXx: www.youtube.com
MCDONALDS TRANSFORMERS PRIME HAPPY MEAL TOYS - 2012 FULL SET REVIEW
MCDONALDS TRANSFORMERS PRIME HAPPY MEAL TOYS - 2012 FULL SET REVIEW
MCDONALDS TRANSFORMERS PRIME HAPPY MEAL TOYS - 2012 FULL SET REVIEW
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Physics - Transformers and Generators
The principle how transformers and generators work is based on electromagnetic induction.
Generators generate current and transformers convert between current and voltage.
A generator is a machine which, with the help of magnetic induction, converts mechanical energy into electrical energy. This is possible by the revolution of coils in a magnetic field (a generator with exterior fields) or by the revolution of electromagnets around a fixed coil (a generator with internal fields). Generators usually generate alternating current, which may, using various devices, be converted into direct current. Generators work in the opposite manner as electrical motors, although an electrical motor can operate in the same way as a generator.
A transformer converts voltage into higher or lower voltages. Different voltage levels are used when generating electrical power, when transferring it, or when using it in a plant or in the home.
A transformer is made of two coils (primary-field and secondary-inductance), between which there is no electrical contact. If we allow a current to pass through the primary coil, a magnetic field is generated which changes but which maintains the same frequency. This succeeds in generating an alternating voltage in the secondary coil. An alternating current passes through a secondary coil when its electrical circuit is closed. The ratio or the size of the current then depends on the number of windings in the coil. If there are more windings in a secondary coil than in the relating primary coil, its voltage increases (and opposite in the other case). The greater the difference between the number of windings in the respective coils, the greater is the difference between their voltages.
The output of an electrical current cannot be changed by a transformer in that, if the voltage is increased, the quantity of current passing through it decreases because the product of both values must always remain the same. This effect is used when transferring electrical current. With electricity transferred over large differences, large voltages are transferred at very slow currents, which results in lowering any losses which may take place during the transfer.
Physics - Transformers and Generators
Transformers War for Cybertron Walkthrough - Part 37 [Chapter 10] One Shall Stand ENDING Let's Play
Video Clips. Duration : 21.75 Mins.
Transformers War for Cybertron Walkthrough - Part 37 [Chapter 10] One Shall Stand ENDING Let's Play
Transformers Fall of Cybertron Walkthrough - Part 1 [Chapter 1] The Exodus Prologue Let's Play PC PS3 XBOX ( Gameplay / Commentary ) www.youtube.com Transformers Fall of Cybertron Walkthrough! Walkthrough and Let's Play Playthrough of Transformers Fall of Cybertron Walkthrough with Live Gameplay on PC XBOX and PS3 in high definition. Check out my channel for more gameplay and commentary www.youtube.com My Twitter Page: twitter.com My Facebook Fan Page: on.fb.me
Transformers War for Cybertron Walkthrough - Part 37 [Chapter 10] One Shall Stand ENDING Let's Play
Transformers War for Cybertron Walkthrough - Part 37 [Chapter 10] One Shall Stand ENDING Let's Play
Transformers War for Cybertron Walkthrough - Part 37 [Chapter 10] One Shall Stand ENDING Let's Play
No URL Transformers War for Cybertron Walkthrough - Part 37 [Chapter 10] One Shall Stand ENDING Let's Play
10 Famous Celebrities Wearing Green Contact Lenses!
It's true- green contact lenses are found by some of our favourite Hollywood celebrities. Ever since green contacts started becoming more fashionable amongst Asian young girls, these gorgeous and beautiful Hollywood celebs have noticed how powerful the effect of green contact lenses are.
1. Tyra Banks
This former supermodel and TV host is famous for facial characteristics and her eyes that smile. Her eyes constantly change color, her own natural color is a kind of greenish-brown. You will also see them to be a purer hue of green which is not her natural color but comes from green contact lenses.
2. Katie Holmes
The actress Katie Holmes was born in the place Toledo Ohio. She has dated Joshua Jackson but married the handsome actor Tom Cruise. Katie has naturally brown hair color and brown eyes. She often wears colored contacts but green colored lenses are her favourite.
3. Lindsay Lohan
Lindsay Lohan is an actress, pop singer and model. Lindsay is a star to many and a favourite target of the paparazzi. She likes to shake things up once in a while by changing her already natural green eyes to a more intense fierce green color.
4. Jennifer Garner
Wears green contact lenses in Elektra and Daredevil. Even though the Elektra in the comic book has got brown eyes, which is the natural eye color of Jennifer.
5. Rachel McAdams
Rachel McAdams grew up in St. Thomas, Ontario. At the age of 13, she was performing in Shakespearean plays in summer theatre camp. She looks beautiful with green colored contact lenses.
6. Mila Kunis
She is also known for playing Jackie Burkhart in the popular "That 70's Show". Mila is often spotted with green contact lenses. Her breakthrough movie was "Forgetting Sarah Marshall".
7. Pamela Anderson
She has been discovered at a British Columbia Lions football game that Pamela attended. She worn a Labatt's Beer T-shirt and her image was shown on the stadium's big screen. The fans cheered to this beautiful bombshell. She has naturally blue eyes but loves to wear green contact.
8. Shia LaBeouf
Shia Saide LaBeouf is an US actor, comedian and voice actor. LaBeouf played as Sam Witwicky in the Transformers sequel Transformers: Transformers: Revenge of the Fallen. He likes to wear green contacts to make is boyish look more sexy.
9. Jennifer Aniston
Jennifer Aniston is gorgeous. That does not stop her from being fashionably inventive with her looks. She has naturally brown eyes but she is often seen with a set of green eyes. This is thought of to be her favourite eye color, but of course come from green contact lenses.
10. Penelope Cruz
The Latinacelebrity Penelope Cruz is also a big fan of green colored lenses. She was born with naturally gorgeous brown eyes. But sometimes she likes to have fun with green contact lenses, combined with sexy and interesting ensembles.
I could go on and on and on, but the bottom line is this: seeing celebrities put on a set of green colored contacts, you know these will be the latest fashion trend.
10 Famous Celebrities Wearing Green Contact Lenses!
Transformers: Fall of Cybertron - Previously On...War for Cybertron: Chapter 1: Dark Energon
Video Clips. Duration : 2.98 Mins.
Transformers: Fall of Cybertron - Previously On...War for Cybertron: Chapter 1: Dark Energon
Getting excited for Transformers: Fall of Cybertron? Get familiar with the story from Transformers: War for Cybertron. Subscribe to our Transformers: Fall of Cybertron show for updates on our walkthrough, gameplay and achievement guides www.youtube.com These Transformers: War for Cybertron videos were put together by Br1zzo www.youtube.com Transformers: Fall of Cybertron Achievements wikigameguides.com WikiGameGuides Steam group steamcommunity.com Twitter @JohnTarrJr goo.gl Twitter @ExplicitD goo.gl Facebook goo.gl Google+ goo.gl Twitch.tv Livestreams goo.gl Our podcast: 2 Chimps on a Davenport goo.gl Support us by using our Amazon Affiliate link goo.gl
Transformers: Fall of Cybertron - Previously On...War for Cybertron: Chapter 1: Dark Energon
Transformers: Fall of Cybertron - Previously On...War for Cybertron: Chapter 1: Dark Energon
Transformers: Fall of Cybertron - Previously On...War for Cybertron: Chapter 1: Dark Energon
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Transformers Games
It is indeed genius marketing trick, transforming bestseller video games into movies and vice versa. Although, nothing but a disappointment for loyal funs. Think back, do you remember Resident Evil? People used to whine about it for a really long time. Sure, judging by the box office it was a great success, the fact is most of people who actually had an idea about RE prior to watching the movie, DID NOT like it, box office success was anticipated according to amount of video game funs. So what drove all these people to cinemas was just an interest. It was exactly the same for Tomb Rider. Sure it was fun to see A. Jolie as a Lara Croft but movie was a total Crap!
Well Transformers the game. People used to spend endless hours not just in childhood watching the most perfect and magnificent Anime ever made. I'd say there aren't many people who don't know about mighty Optimus Prime.
Transformers the game is a multiplatform video game, X360, PS2, PS3, Wii, PC and even NDS and PSP.
System Requirements for PC:
Pentium 4 2 GHz, 1 GB RAM, VGA 64 MB (GeForce 4 or better), 4 GB HDD, Windows XP/Vista.
It's a Third person shooter/Action game. Player can choose between autobots and Decepticons (what a surprise) Robots have multiple attack types, something like light weapon, heavy weapon, melee and ability to throw cars and stuff like that. Well obviously they can transform into cars and back to robot form, which is important for some missions. Collection of "Energon cubes" unlocks cool videos, photos, special characters etc. In other words, all of this was predictable but the work developers have done wasn't effortless. It is actually quite engaging. Cool gameplay. Pretty nice graphics and sound effects especially the Wii version. Many people, especially the ones who are into "mecha" type games going to like it. I'm saying it could have been much better!
Transformers Games
Transformers Fall of Cybertron - The Destroyer's Mighty Paw! Multiplayer Gameplay (DEMO) Commentary
Video Clips. Duration : 12.75 Mins.
Transformers Fall of Cybertron - The Destroyer's Mighty Paw! Multiplayer Gameplay (DEMO) Commentary
Just lovin' this game right now :D Thank you guys for an awesome community! Playlist: www.youtube.com Too Many Big Guns: www.youtube.com Links: www.youtube.com www.youtube.com www.twitch.tv www.twitter.com www.facebook.com
Transformers Fall of Cybertron - The Destroyer's Mighty Paw! Multiplayer Gameplay (DEMO) Commentary
Transformers Fall of Cybertron - The Destroyer's Mighty Paw! Multiplayer Gameplay (DEMO) Commentary
Transformers Fall of Cybertron - The Destroyer's Mighty Paw! Multiplayer Gameplay (DEMO) Commentary
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Grounding Transformers - Electrical Design, Transformer Design, and Distribution Transformer Design
Grounding is clearly one of the most important aspects of electrical design, but it steadfastly continues to be misinterpreted and misunderstood. Millions of dollars in liability and loss can be attributed to ground-fault arcing; thus, grounding-related issues should top the checklists of any electrical contractor.
Grounding Transformers:
Simply put, a grounding transformer is used to provide a ground path to either an ungrounded "Y" or a delta connected system. Grounding transformers are typically used to:
Provide a relatively low impedance path to ground, thereby maintaining the system neutral at or near ground potential Limit the magnitude of transient over voltages when re-striking ground faults occur Provide a source of ground fault current during line-to-ground faults Permit the connection of phase to neutral loads when desired
If a single line-to-ground fault occurs on an ungrounded or isolated system, no return path exists for the fault current, thus no current flows. The system will continue to operate but the other two un-faulted lines will rise in voltage by the square root of 3, resulting in overstressing of the transformer insulation and other associated components on the system by 173%. MOV lightning arresters are particularly susceptible to damage from heating by leakage across the blocks even if the voltage increase is not sufficient to flash over. A grounding transformer provides a ground path to prevent this.
Large multi-turbine wind farms provide an example of the use of grounding transformers for fault protection on ungrounded lines. In many wind farms the substation transformer provides the sole ground source for the distribution system. When a ground fault on a collector cable causes the substation circuit breaker for that cable to open, the wind turbine string becomes isolated from the ground source.
The turbines do not always detect this fault or the fact that the string is isolated and ungrounded; thus the generators continue to energize the collector cable, and the voltages between the un-faulted cables and the ground rise far above the normal voltage magnitude as described above. A grounding transformer placed on the turbine string provides a ground path in the event the string becomes isolated from the system ground.
Construction:
Grounding transformers are normally constructed either with
A ZigZag (Zn) connected winding with or without an auxiliary winding or As a Wye (Ynd) connected winding with a delta connected secondary that may or may not be used to supply auxiliary power
The geometry of the Zig-Zag connection is useful to limit circulation of third harmonics and can be used without a Delta connected winding or the 4- or 5-leg core design normally used for this purpose in distribution and power transformers. Eliminating the need for a secondary winding can make this option both less expensive and smaller than a comparable two-winding grounding transformer. Furthermore, use of a Zig-Zag transformer provides grounding with a smaller unit than a two-winding Wye-Delta transformer providing the same zero sequence impedance.
Wye connected grounding transformers, on the other hand, require either a delta connected secondary or the application of 4 or 5 leg core construction to provide a return flux path for unbalanced loading associated with this primary connection. Since it is often desirable to provide auxiliary power from the grounding transformer secondary winding, this benefit can sway the end user to specify a two-winding grounding transformer in lieu of a Zig-Zag connection. The current trend in wind farm designs is toward the Wye connected primary with a delta secondary.
It is important to understand that both Zig-Zag and two-winding grounding transformers can be provided with the ability to provide auxiliary power, and this can be either a Wye or Delta connected load.
A solidly grounded system using a grounding transformer offers many safety improvements over an ungrounded system. However, the ground transformer alone lacks the current limiting ability of a resistive grounding system. For this reason, neutral ground resistors are often used in conjunction with the grounding transformer to limit neutral ground fault current magnitude. Their ohm values should be specified to allow high enough ground fault current flow to permit reliable operation of the protective relaying equipment, but low enough to limit thermal damage.
How to Specify a Grounding Transformer
The basic parameters required for quoting a grounding transformer are:
Primary Voltage - This is the system voltage to which the grounded winding is to be connected. Don't forget to specify the BIL also. In some cases the BIL will be dictated by equipment considerations, such as 150 kV BIL ratings on 34500 volt wind farms because of the limitation on dead front connectors. Rated KVA - Because the grounding transformer is normally a short time device, its size and cost are less when compared with a continuous duty transformer of equal kVA rating. For this reason, grounding transformers are often not sized by "kVA" but by their continuous and short time current ratings. Regardless of how you rate it, the grounding transformer must be sized to carry the rated continuous primary phase current without exceeding its temperature limit. This load includes the magnetizing current of the core, the capacitive charging current for the cables, and any auxiliary load if applicable. The higher this value, the larger and more costly the transformer will be. Typical continuous current values can be as low as 5 amps to as high as a few hundred. Be sure to include any auxiliary loading requirements. Continuous Neutral Current - The continuous neutral current is defined as three times the phase to current, or in other words, the zero sequence current. This is usually considered to be zero if the system is balanced. However, for the purposes of designing a grounding transformer, it is a value that is expected to flow in the neutral circuit without tripping protective circuits (which would force the current to be zero) or the leakage current to ground that is not a symmetrical function. Again this value is needed to design for thermal capacity of the grounding transformer. Fault current and duration - This value is needed to calculate the short time heating that results from a fault on the system and should be determined from an engineered system study. Typical values for this range from a few hundred amps to a few thousand amps with duration times expressed in seconds and not cycles. For instance, a value of 400 amps for 10 seconds is typical. The fault duration is a critical parameter for the transformer designer. Where protection schemes use the grounding transformer for tripping functions, a relatively short time duration is specified (5 -10 seconds). On the other hand, a continuous or extended neutral fault current duration would be required when the grounding transformer is used in a ground fault alarm scheme. Impedance - The impedance can be expressed as a percentage or as an ohm value per phase. In either case it should be chosen so that the un-faulted phase voltages during a ground fault are within the temporary over-voltage capability of the transformer and associated equipment, such as arresters and terminal connectors. Because of this description, the values can vary from as low as 8% to almost 100%. This value must come from the system designer. Primary winding connection - Specify the type of primary connection, either Zig-Zag or grounded Wye. Secondary connection - specify the secondary voltage and connection when applicable. Specify the size of auxiliary loading to be connected for either Zn or Wye connected primary windings. If the option is to have a two winding transformer with no secondary load, advise if the delta winding can be "buried" (that is not brought out) or if only one bushing is to be brought out for grounding to the tank or testing.
· Basic overall construction features - note the following features as they apply to each transformer
· Compartmental Padmount transformer with integral tamperproof compartment or substation design
· Outdoor or indoor
· Fluid type- mineral oil, silicone, Envirotemp FR3
· Connectivity -dead front, live front, spade terminals, location of terminals - cover or sidewall , exposed or enclosed, etc
· Temperature rise is assumed to be 65'C
· Site elevation or environmental concerns
· Special paint as required
· Neutral Ground Resistors - The rated voltage of the NGR should be equal to the line to ground voltage of the grounding transformer. The current rating and duration should match the grounding transformer ratings. Remember to set the current rating high enough to be above the cable charging current and grounding transformer magnetizing current.
Grounding Transformers - Electrical Design, Transformer Design, and Distribution Transformer Design
Transformers War for Cybertron - Premature Whirlwind - Live Stream Commentary
Tube. Duration : 5.52 Mins.
Transformers War for Cybertron - Premature Whirlwind - Live Stream Commentary
Sometimes Warpath gets too excited -- Recorded live www.twitch.tv www.youtube.com www.youtube.com www.youtube.com www.twitch.tv www.twitter.com www.facebook.com
Transformers War for Cybertron - Premature Whirlwind - Live Stream Commentary
Transformers War for Cybertron - Premature Whirlwind - Live Stream Commentary
Transformers War for Cybertron - Premature Whirlwind - Live Stream Commentary
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Choosing Right Transformer For Mining Industry
Introduction
The US has one of the largest mining industries in the world - an industry closely linked with the economy. In the past, the discovery of resources such as gold and oil resulted in a major population shift and rapid growth for formerly remote regions of the country, such as California, Texas, and Alaska. Extraction of these resources, and finding new deposits, continues to provide the foundation for local economies in some regions.
Some of the minerals mined in the US are coal, uranium, copper, gold, silver, iron, lead, zinc and others. Most of the mines in the US are highly automated and thus energy intensive. To provide an example, even in the last decade of the 20th century, iron ore mining alone consumed 62.3 trillion Btu of energy across a calendar year. Because mining is such a large industry and makes a sizable contribution to the national income, mines must have a dependable source of power - a crucial resource for mining processes.
The mining and mineral extraction sector both in the US and worldwide relies heavily on energy to harness natural resources such as aggregates, precious metals, iron ore, oil, gas, and coal. This energy is used to power shovels and drills for excavating these products, loading them into enormous mining trucks or onto conveyer belts, sorting, sifting and crushing ores, heating, and a hundred other functions. Both surface and underground mining operations rely on powered equipment to extract materials and load trucks. Overall, the mining sector could not flourish without the use of vast amounts of energy.
The Role of Transformers
Mine 'Power Centers' or 'Load Centers' are an essential system for underground and surface mining. Their primary function is to convert distribution voltage into utilization voltage for equipment operation, thus placing power transformers at the heart of the load center. Proper selection of transformers is imperative, and must fulfill safety, reliability, and efficiency requirements. Determining capacity rating is among the first steps for selection of a power transformer for a mining load center. A rule of thumb here is to allow 1 kVA for every horsepower of connected load. Most mining processes, however, do not produce constant loads - all machinery is not connected all the time - and therefore the 1 kVA per horsepower thumb rule will typically result in transformer oversizing. According to the SME Mining Engineering Handbook by Howard L. Hartmann, "Past experience and demand factors established by manufacturers and operators, along with the horsepower of the connected load, are essential for determining transformer capacity. For typical underground mining sections, the kVA rating may lie within the range of 50 to 80% of the connected horsepower."
Transformer Losses
Standard transformers while under full load operate at 90 to 95% efficiency, with this figure dropping as the load lightens. This is due to inefficiencies in the transformer's core, a main component of the transformer. The losses in the core remain the same throughout the transformer's operating range. At 100% load, the amount of comparative loss is negligible. However, at reduced loads, the same amount of energy loss represents a higher percentage of energy being wasted. Unfortunately, average transformer loads run between 34 and 50% of the transformer's total capacity. With the majority of the electricity used
in the US being run through transformers at these lower loads, massive amounts of energy are being wasted. This issue is of special relevance to the mining industry, simply because of its high energy usage. Mining operations also involve hostile environments full of dust, dirt, chemicals, moisture and airborne contaminants. Load center transformers need to function reliably and efficiently in these environments over a long term.
Without electric power at mining facilities, the natural materials extracted from the earth in the mining process would be much more costly than they are today. Thus, power transformers provide a lot of muscle, capacity, and stability to an essential industry. From drilling trenches to busting up rock, carting out huge loads of materials and pulling up heavy amounts of minerals, power transformers provide the strength and capability needed.
Liquid Filled and Dry Transformers: Performance Characteristics
1.Liquid-Filled Transformers
While there is still debate on the relative advantages of the available types of transformers, there are some performance characteristics that have been accepted: • Liquid-filled transformers are more efficient, have greater overload capability and longer life expectancy. • Liquid-filled units are better at reducing hot-spot coil temperatures, but have higher risk of flammability than dry types. • Liquid-filled transformers sometimes require containment troughs to guard against fluid leaks. • Liquid filled transformers are smaller in size than dry-type units for the same power rating capacity and have lower losses because of their better thermal dissipation characteristics.
2.Dry Type Transformers
Dry type Transformers are usually used for lower ratings (the changeover point being 500kVA to 2.5MVA). They are usually placed indoors, serving an office building/apartment. Dry type units typically come in enclosures with louvers, or sealed.
Dry type transformers use almost no flammable materials and therefore do not constitute a fire hazard when used underground in both coal and other mines.
Dry type transformers in the mining industry are housed in a steel tank and the core and windings are cooled by air circulating within the tank, transferring heat to the steel tank which is in turn cooled by the external air. In some compact designs for mounting on mining machines water cooling is added to further improve the performance of the transformers.
Correct choice of insulating materials and an understanding of the cooling system is imperative if the transformer is to be correctly designed. For example, a temperature rise test conducted on a transformer manufactured and sold as continuously rated, can reveal that the transformer only had a continuous rating of 65% of the nameplate rating.
The Need for Energy-Efficient Mining
With the current focus on climate change and reduction of environmental impact, government agencies around the world are making increasingly stringent demands on industries to reduce energy consumption and manage waste more effectively, among others. It is surprising how many mining operations still use twenty-year-old technology.
Regulatory pressures are already beginning to affect the mining industry - according to an article on 'US Environmental Regulations and the Mining Industry' on the International Development Research Center (IDRC) website, "Environmental regulations have had an effect on the US mining industry's profitability. Companies have been forced to retrofit or renovate installations or leave the market. Increasing operational costs have affected their international competitiveness, and to some extent, this may be changing the world allocation of mining investment. Employment levels have fallen substantially, and local economies have borne part of this cost."
Mining companies in the US are thus feeling the pressing need to be energy-efficient, simply to stay competitive. Reducing energy consumption by adopting customized, cost-effective solutions like NEMA-approved transformers and harnessing solar or wind energy to meet their future energy needs can be good ideas in the long run, especially since the alternate energy option will help mining companies keep away from fluctuating international fuel prices. Alternate sources of energy are still a very small blip on the graph, in terms of actual power provided for industries like mining, and thus the sector as a whole needs to come up with more immediate ways to conserve energy.
Various types of transformers for the mining industry:
Transformers can be used in various open pit and hard rock (subterranean) applications that range from auxiliary lighting loads to power for cranes, drag lines, conveyor belts and other miscellaneous dedicated variable speed drive applications.
Benefits of energy-efficient mining
• Reduced cost of production
• Opening up of new reserves for Conclusion
On one hand the mining industry is all set to grow to keep up with increasing demand; on the other it has to stay competitive as fuel prices zoom upwards. For an energy intensive industry, keeping a check on fuel consumption and cost is critical. Thus the mining industry as a whole is looking for energy efficient technology, including power transformers.
Choosing Right Transformer For Mining Industry
Transformers Fall of Cybertron Walkthrough - Part 15 - Megatron Rises Lets Play
Tube. Duration : 11.83 Mins.
Transformers Fall of Cybertron Walkthrough - Part 15 - Megatron Rises Lets Play
Thats Cheating!!!
Transformers Fall of Cybertron Walkthrough - Part 15 - Megatron Rises Lets Play
Transformers Fall of Cybertron Walkthrough - Part 15 - Megatron Rises Lets Play
Transformers Fall of Cybertron Walkthrough - Part 15 - Megatron Rises Lets Play
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Dry Type and Liquid Filled Transformers - A Quick Comparison
Transformers under load generate heat due to winding (copper) and core losses occurring during operation. There is an 'acceptable' temperature rise for transformers used in power applications, and this can even limit their size. This acceptable temperature rise is directly related to the limitations of the transformer materials; safety regulations; or component parts in close proximity that may have high-temperature reliability problems.
High temperatures can damage the winding insulation; the heat generated from core and winding losses must thus be dissipated. This dissipation can be achieved with a combination of radiation and convection from the exposed surfaces of the transformer. Dry type power transformers up to several hundred kVA can usually be cooled by convection or even by fans. Power transformers can also be immersed in coolant liquids - which can range from mineral oils to silicone-based oils or ester-based vegetable oils..
Based on the type of cooling used, transformers are thus classified into 'dry type' and 'liquid-filled'.
Liquid-Filled Transformers
* Oil-filled Transformers
Oil-filled transformers primarily use mineral-based oil and cellulose paper (Kraft or Aramid) in their insulation systems. This proven combination exhibits outstanding thermal and dielectric properties at a relatively low cost. So popular and effective are these units, that all other transformer designs are judged in relation to them. They are still unparalleled in terms of purchase cost, among all the options available. The inherent weakness of a mineral oil-filled transformer, of course, is flammability; which is why oil-filled transformers are usually restricted to outdoor installations, or indoor installations that have elaborate means of fire protection.
Typical Applications:
Oil-filled transformers, thanks to their lower purchase costs, find applications in literally every sort of power distribution. Of late, the awareness of the fire risks associated with mineral oil-filled transformers has created a movement towards safer alternatives that use non-flammable, biodegradable liquids, or even dry-type transformers.
* Non-Flammable Liquid-Filled Transformers
Polychlorinated biphenyl (PCBs) were produced in large quantities starting as early as the 1930s, in response to the electrical industry's need for a less flammable substitute for mineral oil as a cooling/insulating fluid for transformers. Several industrial incidents, however, brought the toxicity of PCBs to the fore. As confirmed organic pollutants, PCBs were banned by the late 1970s. A number of alternatives have since surfaced - major ones being silicone, perchloroethylene, high temperature hydrocarbons, and mixtures of oil with perchloroethylene. The first high molecular-weight hydrocarbon-based fluid (HMWH), was introduced in 1975. This fluids possesses similar dielectric properties as mineral oil, provide remarkable levels of fire-resistance, and do not have undesirable environmental fallouts.
Typical Applications:
Non-flammable liquid-filled transformers can be installed indoors and outdoors, close to buildings, walkways and rooftops. Usually, no additional infrastructure is required to address issues like fire safety.
* Biodegradable Fluid Liquid-Filled Transformers
Animal fats and vegetable oils offer substitutes that are significantly less harmful to the environment than petroleum oils. However, vegetable oils were not used in transformers for a long time; a fluid which could be stable in the transformer environment and available in the required quantities was simply not available.
Transformer manufacturers have since worked on transformer designs that utilize vegetable oil-based dielectric fluids. Comparable in size and electrical performance to conventional liquid-filled units, these transformers are filled with the less flammable dielectric fluids mentioned above. The immediate advantages of biodegradable fluids are clear: higher fire and flash points, thus reducing flammability concerns. The other, and perhaps more long-term advantage, is the fluid's biodegradability: it has demonstrated high environmental assimilation (over 95% in less than a month) - and it has the virtue of coming from a toxin-free resource.
Typical Applications:
Biodegradable fluid liquid-filled transformers find application in wind turbines, and other indoor and outdoor areas of heightened environmental and safety sensitivity.
Dry Type Transformers
* Vacuum Pressure Impregnated (VPI) Conventional Dry Types
Dry type transformer construction uses high-temperature insulation that exceeds the ratings of cellulose or 'O' and 'K' class fluids. Modern conventional dry type transformers feature insulation systems comprising carefully coordinated high-temperature (220'C) materials coated with a high-temperature, moisture-resistant polyester sealant. On better quality premium units, the polyester sealant is typically applied with a vacuum pressure impregnation (VPI) process. Units built in this fashion have exhibited high resistance to most chemical contaminants. Dry type transformers are generally rated up to 30MVA; performance under overload is demonstrably limited, but the addition of cooling fans can usually help augment this.
Typical Applications:
Dry type transformers have been used effectively in diverse commercial and industrial environments for decades; at ratings exceeding 15 kVA. Appropriately designed and installed, VPI units can even be an exceptionally economical choice in medium voltage distribution (15 kVA, 10 MVA ratings), even with the inclusion of installation costs. Because of reduced fire risks, these transformers have been used successfully in special applications where the public are in close proximity, such as underground tunnels, residential apartments, oil rigs and more.
* Gas-Filled Dry Types
Gas-filled dry type transformers are designed for applications where low flammability is a vital consideration. N2, C2F6, and SF6 gases are the ones used in these designs, providing a dielectric medium that is external to the windings. Apart from being the dielectric medium, these gases also act as the thermal medium to transfer heat from windings to tank walls. Gas-filled transformers are an alternative to dry-type construction with fewer fire and contamination risks.
Typical Applications:
Gas media have somewhat limited thermal capabilities; and gas-filled dry type transformers usually do not exceed 3750 kVA (C2F6) or even 2000 kVA (N2). Their design also makes them considerably larger than oil-filled units - anywhere from 20% to 30% bigger. Properly designed and installed gas-filled transformers can operate in any environment and remain truly non-flammable. They are commonly installed in dry-docks to provide local power for shipbuilding. Dry-docks (including transformers) are eventually flooded to float the ship away from the construction site.
* Vacuum Pressure Encapsulated (VPE) Dry Types
Military shipboard use is an exacting requirement, and VPE dry type transformers were developed to meet these needs. VPE transformers are similar to VPI transformers, but employ a resin made of silicone instead of polyester. The VPE method includes several dip processes to encapsulate the coil assembly; the coatings are then cured in an oven. The resin coating in the VPE design is also typically thicker, sometimes by as much as a factor of four; as can be expected, the thermal classification of the insulation system is markedly different for the military than for commercial applications. VPE transformers are more resistant to harsh and wet environments than VPI type counterparts.
Typical Applications:
VPE dry type transformers typically find applications in very harsh indoor and outdoor environments. VPE technology allows the transformer to be highly resistant to humid and caustic environments, but carefully designed enclosures are still a must.
* Epoxy Coated Dry Types
Epoxy coated, or 'epoxy shielded' dry type units offer the benefits of better environmental protection, minimal noise, high basic impulse levels and better short circuit strength than cast coil types. Epoxy shielded transformers are also usually less expensive, flexible, smaller and lighter. There are typically two variants of epoxy coated transformers - in one, a VPI dry-type is given an overcoat of epoxy varnish; in the other, the epoxy varnish is used as a complete replacement for the polyester sealant.
Typical Applications:
Epoxy coated transformers can be ideally suited for environments that may be polluted with acids, alkalis and chlorides. They are also resistant to the effects of salt water and high humidity, thus finding numerous applications in areas which concentrations of these problems.
* RESIBLOC Epoxy Cast Dry Types
Unlike conventional VPI dry type designs, RESIBLOC Epoxy Cast dry type transformers do not use insulation papers in the windings. Instead, pure epoxy resin reinforced with glass fiber rovings are wound directly with the wire. Winding processes controlled by advanced electronics also ensure even distribution and high levels of precision. Aluminum/copper foils are used for the low voltage winding; and circular (or rectangular) copper conductors with glass-fiber reinforced epoxy resin insulation are used for the high voltage windings. The completed winding block is then 'cured' in a specially designed oven under rotation. This process enables cast winding production without molds or vacuum. As in most cast epoxy units, the dielectric material on the interior winding is the epoxy itself. RESIBLOC transformers are reliable, environmentally safe, offer extreme fire resistance, have high short circuit withstands, and can be exposed to extreme conditions with minimal maintenance.
Typical Applications:
RESIBLOC? transformers often find applications in energization, ovens, or traction; they are commonly found in the railways, marine propulsion and distribution, in the nuclear energy and windmill power sectors, and in the mining industry.
* Epoxy Cast Dry Types
The primary and secondary coils in epoxy cast dry type transformers are usually wound with copper conductors, pre-heated and placed in a mold which will then be filled with de-gassed and mixed epoxy under vacuum. The molds are then cured in special ovens to allow sound, void-free casting. The result is a winding design that is void-free, hermetically sealed, and with a smooth exterior finish.
Typical Applications:
Epoxy cast dry type transformers are used inside buildings and tunnels, on ships, offshore platforms and cranes, food-processing plants, and more. They are often combined with primary and secondary switchgear and distribution boards, to form compact substations.
Dry Type and Liquid Filled Transformers - A Quick Comparison
Transformers Shockwave Awesome Balloon Sculpture by HappyCabbie of YouTube
Tube. Duration : 4.93 Mins.
Transformers Shockwave Awesome Balloon Sculpture by HappyCabbie of YouTube
Click here for more balloon sculptures like this www.youtube.com A big thank you to the following people www.youtube.com who was kind enough to stay up all night and maintain the live chat that went on while I was broadcasting the construction of this live. www.youtube.com for the thumbnail Rio Meets Her Balloon www.youtube.com Optimus Prime Balloon www.youtube.com Lion Force Voltron Balloon www.youtube.com Balloon Grinch www.youtube.com Balloon Jack Skellington www.youtube.com Vegeta celebrates my over 9000 subscribers www.youtube.com Learn how to make balloons here www.youtube.com This balloon creation was made live on the internet. Follow me on Twitter for the next time I go live www.twitter.com Yes I am well aware of my weight problem, cheer me on as I work to do something about it www.youtube.com Daily Vlogs are posted here www.youtube.com
Transformers Shockwave Awesome Balloon Sculpture by HappyCabbie of YouTube
Transformers Shockwave Awesome Balloon Sculpture by HappyCabbie of YouTube
Transformers Shockwave Awesome Balloon Sculpture by HappyCabbie of YouTube
No URL Transformers Shockwave Awesome Balloon Sculpture by HappyCabbie of YouTube
Physics - Transformers and Generators
The principle how transformers and generators work is based on electromagnetic induction.
Generators generate current and transformers convert between current and voltage.
A generator is a machine which, with the help of magnetic induction, converts mechanical energy into electrical energy. This is possible by the revolution of coils in a magnetic field (a generator with exterior fields) or by the revolution of electromagnets around a fixed coil (a generator with internal fields). Generators usually generate alternating current, which may, using various devices, be converted into direct current. Generators work in the opposite manner as electrical motors, although an electrical motor can operate in the same way as a generator.
A transformer converts voltage into higher or lower voltages. Different voltage levels are used when generating electrical power, when transferring it, or when using it in a plant or in the home.
A transformer is made of two coils (primary-field and secondary-inductance), between which there is no electrical contact. If we allow a current to pass through the primary coil, a magnetic field is generated which changes but which maintains the same frequency. This succeeds in generating an alternating voltage in the secondary coil. An alternating current passes through a secondary coil when its electrical circuit is closed. The ratio or the size of the current then depends on the number of windings in the coil. If there are more windings in a secondary coil than in the relating primary coil, its voltage increases (and opposite in the other case). The greater the difference between the number of windings in the respective coils, the greater is the difference between their voltages.
The output of an electrical current cannot be changed by a transformer in that, if the voltage is increased, the quantity of current passing through it decreases because the product of both values must always remain the same. This effect is used when transferring electrical current. With electricity transferred over large differences, large voltages are transferred at very slow currents, which results in lowering any losses which may take place during the transfer.
Physics - Transformers and Generators
★ Transformers - Ironhide Gameplay! - Dark of the Moon - WAY➚
Tube. Duration : 5.65 Mins.
★ Transformers - Ironhide Gameplay! - Dark of the Moon - WAY➚
See the full show! ★ Transformers-show.tgn.tv ★ TGN Welcome to the first episode of the Transformers show here on TGN! In this video TheTurtleOfDoom will tell you a little bit about himself, the new Transformers Dark of the Moon video game, and what to expect from the show in the future. Video by TheTurtleOfDoom and TGN Tell us what you think in the comments below. If you like this video, click "Like" and Subscribe to our channel to get more! =-=-=-= ▶ TGN -- Get more views! See tgn.tv ▶ TGN Times -- Get more news! See http ▶ TGN Stratics -- Discover Stratics! See stratics.com ▶ Follow us on Twitter! See http ▶ Join us on Facebook! See facebook.tgn.tv
★ Transformers - Ironhide Gameplay! - Dark of the Moon - WAY➚
★ Transformers - Ironhide Gameplay! - Dark of the Moon - WAY➚
★ Transformers - Ironhide Gameplay! - Dark of the Moon - WAY➚
No URL ★ Transformers - Ironhide Gameplay! - Dark of the Moon - WAY➚
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