Electronics Electrical Interview Questions, Tutorials, Circuits, Motors, Engines and more: September 2008

Monday, September 29, 2008

Yesterday I surveyed the three phase line supplying three 500 kva transformer.
I'm starting from the tapping pole until last. The reason is to find out what is the main
cause of the tripping in as I noticed in every curve road the construction of the
poles at the top button where the pin insulator installed very near to the steel crossarm
resulting single or double line fault occur specially in rainy season.
therefore we come up a solution to install bogshoe after the angle pin and insulator
to have an extension distance between the primary line wire to steel crossarm.

Comparison of alternating current and direct current in transmission lines

I wonder why most of the transmission lines are used ALTERNATING CURRENT not
DIRECT CURRENT. List below are the following reasons.

Advantages of direct current transmission lines
The advantage of DC transmission lines are only two conductors to be used
and there is no problem of system instability, in a DC line has less corona loss
and reduced interference with communitation circuits, since the same value of
voltage therefore the insulating materials on DC lines experience less
stress compared to AC transmission lines, in a DC transmission lines also no skin
effect on conductors, therefore the entire cross-section of conductor is
usually utilized thereby affecting saving in materials. also same load and
sending end voltage, and voltage drop in DC is less than AC transmission lines and
you no problem of inductance, capacitance and phase displacement which is common
in AC transmission lines.

Disadvantages of direct current transmission lines
The disadvantage of DC you cannot anymore step-up or
step down you voltages in equipment like transformer.
And the generation of power at high DC voltages is difficult due
to communication problems and cannot be usefully utilised at consumer load.

Advantages of alternating current transmission lines
On AC transmission lines has less power losses in high voltage and
there is no commutation problem. possible for step up or step down
voltage.The power can be generated to a high voltage.

Disadvantage of alternating current transmission lines
There is increased of effective resistance due to skin effect and more copper
is required. The construction of AC transmission lines in very much
complicated and costly. There is problems of inductances and capacitances because
it exist in transmission lines.

Adding transformer banking requirements

Adding transformer from existing open delta or two single phase
transformer to make it three single phase transformer
are the same requirements to parallel transformer operation
list below are the requirements.

1. The voltage ratings of both primaries and secondaries must be indentical.
2. The transformer must be properly connected with regards to polarity.
3. The ratio of the equivalent resistance to reactance of all transformers
should be the same.
4. The transformer percent impedance should be the same.

Free download electrical engineering

Electrical Hand Book

Fundamental for high voltage

Electrical Dictionary

Career path of an electrical engineer

I read a book that would be a great help in a profession of electrical engineer.
The carer path, we know that our dicision determines or destiny but what destiny
are you going to. Here's the following tips list below.

1. VISION - Project your destiny while still young. Indentify the state where
you are happy, which kind of work that suit your taste and who you will
be in the near and distant future.Know you destination."A person without a
vision is like a ship without a rudder". It just depends
which direction the wind blows.

2. MISSION - Chart your destiny with a road map. Identify which road you are
going to take in going there. Identify what are to be accomplished. What
should be done to prepare yourself.

3. STRATEGY - Strategize to actualize your mission. Hone your skills and
competencies while there is still time. According to Stephen Covey,
"Sharpen your tools. Train yourself". The story of the disappointment
that led to the " cuaderno" was after all not wasted. It was part of reality,
a part of the never-ending learning. Each learning is a preparation to a
higher level of responsibility.

4. ALIGNMENT - Drive yourself into correct direction desired. According to Jack
Welsh, CEO of the great General ELectric, "Control your destiny or somebody else
will". Align yourself with the company's mission & vision. You will then feel
comfortable in you work.

5. BE A SHINING JEWEL - Broaden your capabilities so that you will be on top
of the heap among jewels. You should have the technology, keeping abreast
of trends & other comptencies that others don't have. Make yourself exceptional.

6. DO IT - Make it happen. Create opportunities. Don't wait for something to
happen. Make yourself a participant to the events. Don't be a fence sitter.

7. KAIZEN - Japanese business philosophy of continuous improvement.
Don't sit on your laurels because if you rest,you rust. It means relentless
adrenaline & energy. Remember, your best may not be
good enough. There should always be an extra mile.

8. TEAM PLAY - Don't think of yourself. Make
something to lift others. Make a clone of yourself. Make others as good
as you are so that others could replace you. Remember, you can't be promoted
to higher position if nobody can replace you. Remember,Management is the art
of making others do it for you.

9. THERE'S NO SUCH THING AS SUCCESS - Never think that you are successful.
Success is relative, intoxicating and momentary. You might be the president
of a company but your family might be in shambles. Thus there should be a balance
of career success. Remember, man's life is an open book until he dies.

10. AIM SMALL BREAKTHROUGHS - A winner never quits, a quitter never wins. You
should learn to accept small breakthrouh as winnings because success is not all
material. What's important is that you are happy in what you are in.

11.GOD'S GRACE - Seek ye first the kingdom of God and everything shall be added
on to you. Your greatest inspiration, mentor and ally is God. No matter how
colossal your efforts are, they are nothing if there is no grace from God.

Electrical inventors

List below with attached picture with their Biodata. They are very popular electrical inventors even up to the present time, one of the remarkable was their family names use as units in the formulas of ohms law.

Ohms Law formula
Voltage(v) = Current(i) times resistance(r)

addtional formula
Power(p) = Current(i) times voltage(v)

The unit of voltage is volt while current is ampere then resistance is ohms and power is watts.

Alessandro Volta
Born 1745 at Como
Died 1827
Facts :
Italian physicist
Educated in the public schools
1774 He became a professor at Royal School in Como
He devised the electrophorus
1776-77 He devised the ignition gases by an electric spark
1779 He became a professor of physics at the University of Pavia for 25 years
1800 He developed voltaic pile
1801 Napoleon made him a count the electrical unit known as volt.

Andre Marie Ampere
Born : January 20, 1775 in Lyon, France
Died : June 10, 1836 in Marseilles, france
Facts :
Mastered in mathematics by the age of twelve without proper schooling
He did not read mathematics books until he was 13 years old.
1797 - 1802 earned by tutoring mathematics
Professor of physic and chemistry at Bourg Ecole Centrale
1809-1828 Apointed professor of mathematics at Ecole Polytechnique
He demonstrated various magnetic
He had discovered elctrodynamical forces between linear wires
1826 electricity and magnetism was published.

George Simon Ohm
Born - March 16, 1789 in Germany
Died - July 6 1854 in Munich, Bavarua Germany
Fact :
1806 He took up a post as a mathematics teacher in a school
in Gottstadt bei Nydau.
1811 He recieved a doctorate from Erlangeon.
1817 He received an offer to become a teacher of mathematics and
physics at Jesuit Gymnasium of Cologne.
1820 He had learned of Oersted's discovery of electromagnetism
1825 He published his first paper about electromagnetic force
produced by a wire.
1826 He gave a mathematical description of conduction in a circuits.
what we called ohms law.
1827 He gave his complete theory of electricity.
1843 He stated the fundamental principle of physiological acoustic.
1849 He He took up a post in Munich as curator.
1852 He achieved his lifelong ambition as chair of physics.

James Watt
Fact :
He is Scottish engineer
He is inventor
one who developed of the steam engine as a practical power source.
1757 He appointed as instrument maker at the University of Glasgow.
He studied the Newcomen steam engine.
1769 He patented a separate condeser
He improved in developed the twin-action piston engine.

Saturday, September 27, 2008

What is a fiber optic ?

So why is this jargon becoming one of the most talked about terms? This means we can now easily exchange large volume of data files through the local area network, So, what exactly is a fiber optic? Well, think of it simply as a glass pipe with a tube size as tiny as your hair having a pulsed light that carries information which travels along its core from one end to the other. It is the ultimate communication media on earth, the most ingenious technology that man has ever invented. In today’s modern world where technology is taking its lead in the society, the role of fiber optic is becoming pervasive to everyday living. Do you know that you are using fiber optic when using your 3G cell phones to send video streams to your friends anywhere in the world? Are you aware that fiber optics enable clearer long distance calls to other countries and allow even better internet surfing? The possibilities that modern technology can offer to the field of human communication nowadays are endless with the fiber optic working hand in hand with other forms of media such as wires,
radios, and satellites. If you ask me. , “Is it true that there is a fiber optic cable linking every country?” I replied, “Yes!” In fact, there are transoceanic submarine fiber optic cables laid throughout the world. In the Philippines, we are
connected to the outside world via Hawaii, Guam, Japan, China, Malaysia and Indonesia through the Batangas fiber optic terminal. Almost all nations are now physically connected via fiber optic cable laid either underground, aerial or undersea. But why are they not using wires or radios instead? Only one word is the answer - “capacity”. Fiber optic’s capacity is virtually limitless that could only be bounded by the transmitter’s capability to send very high speed data. To date, the highest speed attained is only 1 terabyte a second which is equivalent of copying 250 DV disc in just one second, but it can theoritically handle up to 3 terabytes in a single fiber. Aside from the great capacity that it can carry, it has the advantages of being very secured, its being lightning proof, and its noise free.
The great advantage of having this investment are security, bandwidth and connectivity, factors that microwave radio transmission cannot guarantee. One of the apparent applications that this technology has benefited us was the LAN linkage.

Steps to make design and estimate on overhead transmission lines

First in foremost when you make a design and estimate you should have a guide or step in order to less time and fast. below listed my technique on how.

1. Pole - I gathered all the poles from the highest height.

2. Standard construction - grouping all the construction according to its type we have the primary and secondary including also the construction of the transformer.

3. wires - gathered also all wires needed starting from primary, secondary, the guy etc.

4. others - after all are separated by group the last is the materials that are not included in the above 1, 2, 3 steps like the connector, pvc tape, cut-out fuse, clamp, additional materials to standard construction, split bolt.

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what is load transfer ?

During maintenance and upgrading on overhead or underground transmission line we need to off the line and work on the specific area but what if, if has a big customers to interrupt its also a bigamount of money from the company wasted. So therefore there is a sulotion called the interruption free load transfers. But first, what is a load transfer? Load transfers are when power is transferred from
one source to another, and this usually happens during maintenance works and/or upgrades made on a certain substation. Think of it this way, you plug your TV to outlet A and turn it on. Now, you need to work on outlet A, so you turn off the TV, transfer the plug to outlet B, and then turn it back on. This way, you can work on outlet A and still you can enjoy watching the TV being supplied now by outlet B.

this means temporarily interrupting electric service for a number of customers in order for the transfers to take place. Normally, these transfers will require two power interruptions of about 15 minutes each, one before the work and one after. Because of the collective experience

Going back to our analogy, this would roughly imply that we plugged the TV to outlet B (thereby being supplied by both outlet A and B) before we unplugged it from outlet A to prevent any interruption. (CAUTION! This is a rough ANALOGY, please don’t try this at home!) There are a lot of technical requirements to make this happen, and thus, all parameters should be checked, re-checked, and computed to measure its workability. If this is not done with caution, damages could be large.

KELMAN - Transport X Portable Dissolve Gas Analyzer

The deterioration of electrical equipment is normal, and this process begins as soon as the equipment is installed. If this negative impact of the equipment is not checked, it can cause electrical failures and malfunctions. To carry out the successful operation of electrical equipment, it is essential to have effective and
reliable test equipment.

Lately our company buy a new generation test equipment worth P 3.1 million, the KELMAN - Transport X Portable Dissolve Gas Analyzer. A portable and user-friendly
field proven technology, this is used for dissolved gas and moisture analysis of oil-filled equipment. Dissolved Gas Analysis (DGA) is an established technique and recognized as the most important test in monitoring power transformers. It is being successfully extended to oil-filled equipment such as tap-changers and circuit breakers. Transport X uses Photo Acoustic Spectroscopy to achieve unprecedented performance for DGA equipment. This process involves the production of images utilizing sound waves that produce spectra for visible electromagnetic radiation. This device represents invaluable commodity for asset management such as:

· Accurate & Sensitive - wide
detection ranges with excellent
accuracy for all relevant gases.

· Moisture Analysis - gives
measurement of water content
in oil.

· Simple & Fast - extremely
easy step-by-step operation
with no extensive calibration setup
or interpretation required; onsite
results in a matter of minutes.

· No Consumables - no
calibration gases or carrier
gases.

· Portable & Rugged - weighs
10 kg. (22 lbs.) in a rugged
convenient carry case.

· Reliable - engineered design
provides inherent reliability.

· DGA Diagnostics - includes
DGA diagnostic algorithms
Roger’s Ratios, Duval’s
Triangle, and IEEE Key Gas;
also has a user-settable caution
and warning threshold on all
gases; analyzes the condition of
the transformer.

· Test Gas Samples - ability
to test gas samples taken from
Buchholz Relays.

· PC Software - includes
transport Pro PC software
package to allow storage,
exporting, trending, and analysis
of results.

The different combustible
gases that can be detected by
this test equipment are:
1. Hydrogen is a gaseous colorless and odorless highly flammable chemical element
2. Carbon Monoxide is a colorless and odorless very poisonous gas formed by the incomplete burning of carbon.
3. Carbon Dioxide is a heavy colorless gas that does not support combustion.
4. Methane is a colorless and odorless flammable gas produced by decomposition of organic matter.
5. Acetylene is a colorless flammable gas used as a fuel (as in welding & soldering).
6. Ethane is a colorless and odorless gaseous hydrocarbon found in natural gas.
7. Ethylene is colorless flammable gas found in coal gas or obtained from petroleum.
8. Water in form, or secrete water, or watery matter.

I believes that having the KELMAN - Transport X Portable Dissolved Gas Analyzer will help the company maximize its valuable assets, reduce related costs, improve the safety of personnel and property, and, most of all, increase productivity.

Electrical and Electronic theory, laws, principles

Electrical circuit and theory - transformer, how to build transformer, the variable and inductor, magnetic fields, electric fields, induction motor, phase shift, wave forms analysis.

Fundamental network theorems for dc and ac analysis - Ohms laws KCL and KVL, voltage and current devider, Nodal analysis, loop or mesh analysis, superposition, source transformation, thevenin's and norton's theorems.

Electrical formulas - Notation, impedance, admittance, reactance, reasonance, reactive loads and power factor, complex power, three phase power, per unit system, symmetrical components, fault calculation, three phase fault level, thermal short time rating, instrument transformers, power factor correction, reactors, harmonics reasonance.

free Ohms law and power calculator - you can enter any value that you want and it will give automatically the answer

pad mounted transformer

This afternoon october 25, 2007 Copper Power System visit at Don Ramon Aboitiz substation for giving us a seminar and actual instruction on pad mounted transformer.

3Ø Pad-Mounted Transformers
Ratings
kVA: 45 – 10,000
Primary (High) Voltage: 2400 – 46,000 Volts
Secondary (Low) Voltage: 120 – 15,000 Volts
Oil or Envirotemp® FR3™ Filled
55/65º Rise for 12% More kVA

Installation Location
1. Sufficient Space
2. Sufficient Ventillation
3. Stable Mounting Pad

Pre-Service Inspection
Check the exterior of the transformer Dents, Nicks, Scratches on the bushing
Check all the seals and gaskets seepage Tank cover, bushing seals, gauges, fuses, operating devices, etc..
Check the presence of Vacuum
Check the liquid level

External Connections
Transformer must be connected and operated as indicated by the nameplate
Bushing and terminals must be thoroughly clean prior to connection
Allow sufficient flex for all Cables connected to the transformer terminal

Ground Connections
Transformer tank must be connected to a permanent, low resistance ground.
All CPS padmounted transformers are equipped with two grounding pads

High Voltage Connections
Make connections as shown in the diagrams and info on the transformer nameplate
Transformer Neutral to Systems Neutral
Leads and connections that are not used must be insulated from ground and all other leads
Allow sufficient flex for all Cables connected to the transformer terminal
The bushings are positioned to allow vertical take off of the primary cables entering from below

Deadfront Transformers Connections
All 3 phase padmount transformers are equipped with Universal Bushing wells
One-piece bushings or bushing wells with factory installed inserts
Other brand well inserts must be compatible with the universal bushing well otherwise it will cause premature failure of the transformer.

Low Voltage Connections
Check the information on the transformer nameplate (Voltage, Config., BIL)
Transformer Neutral to Systems Neutral
Allow sufficient flex for all Cables connected to the transformer terminal
Use the sec. bushing support if the cable are heavy enough to pull down the bushing

Accessories
Liquid level gauge
Liquid Temperature Gauge
Pressure Vacuum Gauge
Pressure Relief Device
Bay-O-Net Fuse

Switches and Protective Devices
Refusing of Bay-O-Net Fuse
a. Pull ring of
Pressure Relief
valve

Refusing of BaY-O-Net fuse
*SHUTDOWN CONDITION ONLY
a. Pull the ring of Pressure Relief Valve and hold
b. Using Hot stick twist the fuse holder to unlock
c. Turn fuse holder to 90deg. to break seal bet gasket and fuse housing
d. Draw fuse holder out quickly 8 to 10 in.
e. Wait several sec to drain the oil
f. Remove fuse holder from the Bay O net housing
g. Wipe off catridge holder Refusing of BaY-O-Net fuse
h. Use ¾” wrench to remove fuse catridge from holder
h. Insert Replacement Fuse Link of same catalog into the Fuse Catridge

Internal Loadbreak Switch
Two Position LBS
On/Off Switch function

Internal Loadbreak Switch
Sectionalizing LBS
V-Blade 4 Position Sectionalizing LBS
3Ø Pad-Mounted Transformers
4-Position V-Blade Switch
Internal Loadbreak Switch
Sectionalizing LBS
T-Blade 4 Position Sectionalizing LBS

3Ø Pad-Mounted Transformers
4-Position T-Blade Switch

Tap Changer
Hot Stick Operable TC
Lever Handle TC

3Ø Pad-Mounted Transformers
High Voltage Connectors
For Deadfront
Loadbreak Elbow Connectors

3Ø Pad-Mounted Transformers
High Voltage Connectors
For Deadfront : MOVE Surge Arrester
3Ø Pad-Mounted Transformers
High Voltage Connectors
For Deadfront : TOP II Connector

3Ø Pad-Mounted Transformers
High Voltage Connections
Radial Feed - 3 HV Bushings

3Ø Pad-Mounted Transformers
High Voltage Connections
Loop Feed Means 6 HV Bushings to Loop High Voltage Cables In and Out

free electrical magazine

Electricity today - electrical engineering magazine, power engineering information, articles electrical power industry

free trade magazine source - free magazine for electrical industry.

The engineering tool box - tools and basic information for engineering.

Free Trade Publication - The world media guide

High voltage power & engineering e-magazine - with pdf and zip file

free construction magazine - quick and easy way free construction magazine

Transmission and Distribution magazine - free magazine for transmission and distribution

the sources of electrical energy

Biomass energy
Biomass energy - all about aspects of biomass energy, the proccess how they start to produce energy

Information Resources about biomass
biomass free download - with free download about the biomass, case studies, reports,

Geothermal energy
What is geothermal energy ?
Geothermal energy facts
Classification of geothermal power
how geothermal energy is captured.

hydropower
hydropower how it works
Free download hydro power handbook
hydorpower articles

Renewable energy
learning about renewable energy
difinittions renewable energy resources
Photographs of installations renewable energy

nuclear power plants
how nuclear power plants works?
frequently question about nuclear energy
nuclear boiling water reactor

solar energy
free video about solar energy
free pdf file about solart energy
the proccess of a solar energy

tidal energy
free download pdf file about tidal energy
tidal energy systems
complete facts about tidal energy
another free download pdf file about tidal energy

wind power energy
free download pdf file the theory of power energy
how a wind power turbine works free download pdf file and picture
basic of wind power energy and its components

Thursday, September 25, 2008

the fundamentral of electrostatics

the demonstration of electrostatics

the electrostatics machines

complete list topics about electrostatics

electrostatics potential and its formulas

what is electroscope

electrostatics - biot's hemispheres and hollow globe, charge distribution surfaces, ekectrophorous, gold leaf electroscopes, pivot, wimshurst machine

Electric Field, charge, permittivity of free space, attractive, repulsive - free question and answer, formulas

electric charge, electrostatics, electron, proton, neutron, positive and negative ions, principle of conservation of electric charge

Electrostatic charging

presence of electric field - with moving picture for you to more understand the presence of electric field

all about magnetic

magnetics through hand - you need to know how the magnetic force can penetrate through our hands

electricity and magnetism - wants to learn more about magnetics fields, magnetics properties, and more..

magnetism experiments - looking for a magnetism experiments its free..

free pdf file about magnetics field and magnetics lines of force

how to make a simple compass without need an expensive materials.

how Loudspeaker and Microphone works by the power of magnetics

90 percent of Mindanao grid experienced black out

October 28, 2007 Davao Light experienced a total black out of the whole franchise only the downtown area and hospital are automatically on because we have a back up power generator. The main cause is from TRANSCO the reason state below as our supervisor receive a text.

Transco Iligan MRCC. Please be informed that the system experienced major system trouble at 1:04 pm today. The following 138 kv lines trip affecting 90% of mindanao grid: agus 2- kibawe line 1 and 2, abaga-agus 2 line 1 and 2, abaga agus 6 line 1 and 2, abaga-tagloan, abaga-aurora, abaga-lugait, lugait-tagaloan. Initial finding, abaga-agus 6 line 1 conductor flashover/melted at agus 6 switchyard.

electromagnetic induction

The process by which an electromotive force and hence current is generated
or induced in a conductor when there is a change in the magnetic flux, linking
The conductor,is called electromagnetic induction.

Faraday's experiments - Len's law,Some definitions like magnetic flux,
Electromotance or electromotive force e.m.f., motional electromotance
motional electromotance in terms of flux cutting, induced currents and
charges, The differential form of Faraday's law, Self-inductance, Calculation of
sefl-inductance, Magnetic energy(in terms of self-inductance, in terms of the magnetic field)

electromagnetic induction - with moving picture for you to quick understand about electromagnetic Induction and with question and answer, Facts, Len's law and equations of the formula

electromagnetic induction - magnetism, magnetics fields, force & magnetic induction, electromagnetic induction, Back EMF, Transformers.

application of electromagnetic induction - eddy currents, an electric generator, back EMF in electrical generator mutual inductance, self inductance, transformers.

electromagnetic induction - motional emf, example problem, the induced electric field, inductance with problem, magnetic energy with problem, the RL circuit with problem.

electromagnetic induction - with free animation shows a copper rod being moved.

electromagnetic induction - current changes direction with change and magnetic motion,
voltage change polarity with change in magnetic motion, magnetic moved back and forth and its formulas.

KEY FACTS OF ELECTROMAGNETIC INDUCTION

- Good smoothing factor of a coil depends on the induction of the coil.
- Wherever a conductor cuts magnetics flux. an e.m.f. is induced in that conductor. This statement is due to Faraday's law
- Magnetic field intensity is a vector quantity.
- Leakage factor is more than unity.
- It is difficult to magnetize steel because of its low permeability
- A degaussing is the process of the demagnetizing metallic part.

what is alternating current(AC) system

the sinusoidal waveform - dc current vs. ac current, the sinusoidal ac waveform, Instantaneous Current and Voltage,

amplitude of a sinusoidal waveform - Peak and Peak-to-Peak Voltage, RMS Voltage, Average Voltage

frequency and period of a sinusoidal waveform - Period of a Waveform, Frequency of a Waveform , with question and answer

phase angle - Phase Angle , Leading and Lagging Phase Angles

sinusoidal power waveform - AC Power Waveform , Average AC Power

non-sinusoidal waveform - Rectangular Waveform, Amplitude and Period , Period and Duty Cycle , Sawtooth Waveform

basic ac theory - what is alternating current?, what is AC waveforms, measurement of ac magnitude, simple ac circuit calculation
ac phase, principles of radio, contributors.

AC METERING CIRCUITS - ac voltmeters and ammeters, frequency and phase measurement, power quality measurement, ac bridge circuits,
ac instrumentation transducers.

Resistors and Ohm's law in AC circuits

Bandwidth and Q factor

RMS and power in single and three phase AC circuits

What is Automatic Voltage Regulator in transmission and distribution lines

The AVR units maintain
voltages within the allowable
levels. They operate in
similar principle as the
smaller AVR units we use in
our homes. Whenever there
are variations in voltage
feeding by the substations, the
AVR units shall
automatically regulate the
output voltage so that the
customers receive a steady
voltage from their end.

Wednesday, September 24, 2008

The main function of substation

Substations serve as sources of energy supply for the local areas of distribution in which they are located. Their main functions are the following:

1. To receive energy transmitted at high voltage (in Philippines, it is usually 230 kV or 138 kV transmission voltage and 69 kV sub-transmission voltage) from the generating stations;

2. To Reduce the voltage to a value appropriate for local use and provide facilities for switching; and

3. To Provide points where safety devices may be installed to disconnect circuits or equipment in the event of trouble.

Voltage on the outgoing distribution feeders. can be regulated at a substation. It is also a convenient place to make measurements to check the operation of various parts of the system.

All about transmission and distribution lines

Information on High Voltage Overhead Transmission and Distribution lines - what is in a tower?, about phases,circuits and shielding, how high is high?, about different ways to express voltage, electrical fields and induced voltage, telecommunication on high voltage overhead lines.

free transmission lines calculator

Transmission Lines - A 50 ohm cable?, circuit and the speed of light,Characteristic impedance, Finite length transmission lines, Long and short transmission lines, Standing waves and resonance, Impedance transformation, waveguides

How Power Grids Work

3 Phase Power Distribution and Transmission

Flying kite near power line

Inventor Benjamin Franklin He used kite to prove that lighting was a electricity. So therefore playing kite could prove also that be very a good conductor too especially when you are using a materials that does not right.

Overhead transmission lines are very much danger it is because most of the lines
carrying 7620 volt above they are bare conductors which means not insulated.

Substation or transformer installed on pole are live parts also that are dangerous to contact.

Current always seeks the shortest path to the ground,it tries to find a good conductor or something that they can pass through to the ground. Our body contains about 70 percent of water which means current can able to flow. For instance if you are touching a live parts while your feet in on the ground, the current will automatically to flow it causes harmful.

Becuase of that it is better or advisableto stay clear off the electrical wires when flying or playing kites, because it can cause a serious injuries or even death.
The question. How much current can a body take? The answer is it doesn't take much to get hurt even 10 watts of Christmas tree bulb can kill you in a fraction of second if it passes throug your heart.

For safety tips
1. If your kite is caught in power lines or it falls into a substation you must leave there or call an emergency line man of the company.
2. use cotton, linen or any nylon to use as string of your kite.
3. use kites made of good insulator like wood or plastic.
4. before you playing kite always clear and be observant and knowledgeable about electricity.

power factor correction

what is power factor? the power factor is the cosine of the angle between the voltage
and current in the circuit or the ratio of the resistance to the impedance of the circuit and also the ratio of the real to the apparent power. To give more detail regarding power factor please follow the links below for additional information on power factor.

free pdf file for power factor - power in single phase ac circuits, complex power, the complex balance power, power factor correction.

free pdf file for power factor fundamental - power factor correction saves money, what is power factor, the power triangle, why do we install capacitors?, other benefits, summary of benefits for installing capacitor.

free pdf file for three phase theory - balanced load, three phase power, analysis of three phase balanced systems, single circuit of a three phase system, equivalent circuit for three phase balanced system, unbalanced three phase system, sysmetrical components,
graphical methord of solution, power associated with sequence components.

Useful Formulas for Power System Analysis & Power Factor Correction - formula symbols,free calculation for capacitors connected in parallel, capacitors connected in series, capacitive reactance, capacitance, capacitor kilovars, power factors, kilovars required to change power factor, equations for total power factor, total power, reactive power, voltage rise, released system capacity for power factor improvement, loss reduction for correction power factor, capacitor current, total power factor, quality factor, crest factor. note : just click the capacitor and input the value then automatically give you the answer.

power factor - power in resistive and reactive ac circuits, true power, reactive power, apparent power, calculating power factor, practical power factor correction.

free pdf file for power factor - the difference between volt amperes and watts, definition of a volt ampere reactive, a graphical representation of real, reactive, apparent and power factor.

FACTS ON POWER FACTOR

1. The reason why we need to improve power factor is to avoid poor voltage regulation.
2. Another reason is to decrease the reactive power.
3. On magnetizing component of a transformer the power factor is always leading.
4. On incandescent bulb or lamp the power factor is unity.
5. using synchronous motor can improve the power factor.
6. Using static capacitors can also improve the power factor and they are almost loss free.
7. If the system has poor power factor it will result to overloading of transformer as well as alternator.
8. For indicative circuit they can improve the power factor by connecting in series of capacitor.
9. KVAR are rated terms of the capacitors of power factor correction.
10. oN AC circuit which contain both resistor and conductor the power factor is leading between 0-1.

TYPES OF POWER FACTORS
1. unity power factor - equal real and apparent power.
2. leading power factor - when the current leads voltage by an angle and the true power will less than the apparent power.
3. lagging power factor - when the current lags voltage by an angle and the true power is less than the apparent power.
4. zero power factor - when there is phase difference of 90 degree between the current and the voltage. If the circuit has zero power factor you have no useful work to be done.

Electrical Per-unit Calculation

The per-unit method of calculation in its basic concept is to develop a counterpart impedance or reactance network diagram of the power system involved and resolve these impedances down to a single impedance value through delta, wye, series, parallel conversion equations. While it is possible to do the calculation with the actual system ohmic values, it becomes very complex when several voltages levels are involve since ohmic values at different voltages are not directly compatible. With the aid of the per-unit mathematical technique, it has facilitated this difficulty. While the equivalent diagram and the per-unit mathematics are two separate fields, they usually are used together and referred to as the per-unit method of determining short circuit values.

For Medium voltage power system usually benefit the application of the per-unit
method because the analysis normally undertaken involves a relatively few specific points in an existing system. Also in these system, reactance usually far exceeds resistance high X/R ratio, permitting resistance to be ignored, which greatly simplifies the mathematics.

The primary advantages of the per-unit system are as follow:

1. The per-unit values for transformer impedance, voltage and current are identical when referred to the primary and secondary line ( no need to reflect impedances from one side of the transformer to the other, the transformer is a single impedance).

2. The per-unit values for various components lie within a narrow range ragardless of the equivalent rating.

3. The per-unit values clearly represent the relative values of the circuit quantities. Many of the ubiquitous scaling constants are eliminated.

4. Ideal for computer simulations.

The need for fault calculation in design

After my seminar last March 2007 it was a three days seminar on fault calculation
at Cebu Philippines. I become aware with my work when making Design and Estimate, it
is also an eye opener for all Electrical Engineer especially to the newly engineers,
this what happen.

Contrary to the practice of many local engineers, Fault Calculation must precede any effort to procure system protection devices. This activity is supposed to be one major part of the design process, but is oftentimes skipped or omitted.

Several provisions of the National Electrical Code, the Philippines Electrical Code
& IEEE publications ralate to proper system protection. Safe and reliable operation
of the industrial plant based on these provision mandate that electrical system must
be protected adequately & effectively.

While over-current protection devices are provided for overloaded protection for system components such as switchgears, busses, wires & cables, motor controllers, etc. it is also necessary to place protection for more damaging events such as faults. To obtain a reliable operation and to assure that system components are protected from damage during abnormal events, it is necessary to firts calculate the fault duties at various points in the electrical system while still on the drawing boards and adequate protective devices must subsequently be in place to anticipate these faults.

For all possile conditions, it is the responsibility of the system designer to design
electric power systems with adequate control of short circuits as one major consideration. It is also the plant engineer's responsibility to see to it that the protective devices are armed to predetermined settings either by himself or by consultants. As can be recalled, uncontrolled short circuits can cause service outages with accompanying production downtime and associated inconvenience, interruption of essential facilities, extensive equipment damage, personnel injury or fatality and a possible full-blown fire.

Again as the system designer is responsible for the selection of the right equipment, and would generally have the task of calculating system short circuits, procedures and techniques for these calculations are not generally available in on reference dissertation but are scattered among many publication and technical papers.

Fault calculations result to at least three very significant outputs which will
become the bases of the following:

1. First : proper selection of protective equipment ratings as circuit breakers or fuses that suit to system requirements :

2. Second : realistic arming up of protective relays to trigger operation of circuit breakers once faults do occur :

3. Thirdly : Proper coordination of operation of these protective devices to effect selective interruptions of the only required breakers to trip faulted circuits without the hassle of rendering the other portions of the system powerless.

Electric Motor

Electric motor - A motor that converts electricity to mechanical work

electric motor - rotating electrical machines, principles of electric motors, its magnetic field, current, and forces, synchronous motor.

free pdf file for Induction machine with squirrel cage rotor and slip ring rotor - The experiment, experiment preparation, experiment realization.

electric drives - electrical machines fundamentals - principles,
motor action, generator action, alternative motor action, reluctance torque, basic electrical machine, magnetic circuit two pole motor, commutation, motor characteristics, generators.

electric motors - history and development, categorisation of electric motors, dc motors, universal motors, ac motors, torque motors, stepper motors, linear motors, doubly-fed electric motors, doubly-fed electric motor, singly-fed electric motor, nanotube nanomotor, motor calculation, motor standards.

simple electic motors - how it works, technical information, selecttion suggestion,
assembly instructions, experiments and application, troubleshooting, safety rules.

electric machine applications - notation, transformer, induction machines, synchronous machines, direct current machines, efficiency, temperature rise, dielectric dissipation factor.

free pdf file for electrical power and machines - power systems, phasor diagram, three phase power, magnetic circuits, electomechanical engergy, conversion, dc machine, transformers, induction motors, synchronous machine.

a tutorial on electrical motors - motor selection criterias, motor type,

motor formulas - calculating motor speed, calculating braking torque, calculating work, calculating torque, calculating full-load torque, calculating horse power, calculating synchronous speed.

basic motor formulas and calculations - rules of thumb approximation, mechanical formulas, temperature conversion, synchronous speed, frequency and number of poles of ac motors, relation between horsepower, torque and speed, motor slip, symbols, equivalent inertia, electrical formulas, locked rotor current from nameplate data, basic horsepower calculations, accelerating torque, duty cycle.

motor tutorials - ac motors, dc motors, brushless dc motors, servo motors, brushed dc servo motors, brushless ac servo motors, stepper motors, linear motors.

motor comparisons - brush vs. brushless, housed vs. frameless, stepper vs. brushless, induction vs. pm brushless.

free pdf file for motor control fundamentals - motor anatomy, what makes a motor spin?, types of motors, why do we need electronics in the motor?, system level block diagram.

Electrical Formulas

lIST Below links are all free electrical formulas.

electrical formulas etc. - metric conversion, electrical formulas, conduit weight, maximum no. of conduit, 600 volt building wire, weights and ampacities, ampacities of a insulated conductors, copper to aluminum, receptacle configuration.

electrical and mechanical formulas - ohms law, power - ac circuit, power - dc circuit, mechanical, blower motors, pump motors.

useful electrical formulas - to find ampers when horsepower is known, amperes when kilowatts are known, amperes when kilovolt amperes are known, kilowatts, kilo volts amperes, horsepower.

electrical formulas - admittance, ammeter shunt, batteries, capacitance, capacitance in parallel, capacitance and series, charge division by parallel capacitances, compensation theorem, complex power, current division by parallel resistances, delta-star transformation, dielectric dissipation factor, direct current machines, efficiency, energy, fault calculation, harmonic resonance, inductance, inductance in parallel, inductance in series, induction machines, impedance, instrument transformer, joule's law, kirchhof's laws, maximum power transfer theorem, millman's theorem, mutual inductance, norton's theorem, ohm's law, per-unit system, power, power factor, power factor correction, reactance, reactive loads, reactors, reciprocity theorem, resistance, resistance in parallel, resistance in series,
resonance, star-delta transformation, superposition theorem, symmetrical components, synchronous machines, temperature rise, thermal short time rating, thevenin's theorem , thievenins and norton equivalence, three phase fault level, three phase power, time constants, transformers, voltage division by series capacitances, voltage division by series resistances, voltmater multiplier, wheatstone bridge.

free download Formulas, Equations, and Help - unit converter, periodic table of elements, kvar calculator, voltage drop calculator, motor protection calculator, motor calculation, circuit design calculator, conduit fill calculator, 4 function calculator, zonal cavity calculator, arc flash calculator, fault current calculator, lighting system calculator, capacitor kvar calculator, software, residential load calculations, touch potentian 2 wire circuit, conversion formulas, electrical formulas based on 60 hz.

Electrical and Electronics Free Download

Just click each free download and input a password if required as provided.

principles of electrical measurement

An Illustrated guide to wiring a safe house
Code Check Electrical, 4th edition, outlines the principles behind the various accepted electrical codes and provides information on the code requirements for all types of residential electrical systems. It is cross-referenced to the most recent National Electrical Code. The Code Check series is one of Taunton’s most successful book lines, selling over 400,000 copies. Spiral bound, with durable laminated pages, the books in this series are designed to be used on-site for quick reference, ensuring that all jobs meet the highest safety standards while drastically reducing code violation call-backs. The Code Check series is endorsed by the International Conference of Building Officials

Principles and applications for protective relaying
Technological advances and structural changes within the electric utility industry mandate that protection engineers develop a solid understanding of the related new technologies as well as of power system operations and economics in order to function proficiently. Continuing in the bestselling tradition of the previous editions by the late J. Lewis Blackburn, Protective Relaying: Principles and Applications, Third Edition retains the fundamentals of protection relays and power system protection while incorporating new developments in the field. Thoroughly updated and revised, this third edition focuses on technological changes in the design of protective systems, the practical concerns of power system protection encountered by users, and the techniques for protecting typical facilities used in modern power systems. New to the Third Edition · Expanded coverage of the requirements for generator intertie protection, generator protection, and generator excitation systems · The latest technologies in microprocessor applications, including digital-based devices and designs · Protection issues, such as capacitor bank protection, underfrequency and undervoltage load shedding, special protection schemes, DC tripping scheme designs, fault location, and event reports

Engineers and scienteist essential MATlab
This text presents MATLAB both as a mathematical tool and a programming language, giving a concise and easy to master introduction to its potential and power. Stressing the importance of a structured approach to problem solving, the text gives a step-by-step method for program design and algorithm development. The fundamentals of MATLAB are illustrated throughout with many examples from a wide range of familiar scientific and engineering areas, as well as from everyday life.

Statistical quality control and desing the introduction to engineering
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Many have heard that six sigma methods are necessary to survive, let alone thrive, in todays competitive markets, but are not really sure what the methods are or how or when to use them. Introduction to Engineering Statistics and Six Sigma contains precise descriptions of all of the many related methods and details case studies showing how they have been applied in engineering and business to achieve millions of dollars of savings. Specifically, the methods introduced include many kinds of design of experiments (DOE) and statistical process control (SPC) charting approaches, failure mode and effects analysis (FMEA), formal optimization, genetic algorithms, gauge reproducibility and repeatability (R& R), linear regression, neural nets, simulation, quality function deployment (QFD) and Taguchi methods. A major goal of the book is to help the reader to determine exactly which methods to apply in which situation and to predict how and when the methods might not be effective. Illustrative examples are provided for all the methods presented and exercises based on case studies help the reader build associations between techniques and industrial problems. A glossary of acronyms provides familiarity with six sigma terminology and solutions to homework and practice exams are included.

Digital circuit analysis and design
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This text includes the following chapters and appendices: Common Number Systems and Conversions, Operations in Binary, Octal, and Hexadecimal Systems, Sign Magnitude and Floating Point Arithmetic, Binary Codes, Fundamentals of Boolean Algebra, Minterms and Maxterms, Combinational Logic Circuits, Sequential Logic Circuits, Memory Devices, Advanced Arithmetic and Logic Operations, Introduction to Field Programmable Devices, Introduction to the ABEL Hardware Description Language, Introduction to VHDL, Introduction to Verilog, and Introduction to Boundary-Scan Architecture. Each chapter contains numerous practical applications. This is a design-oriented text.

Theory, design and application for wind energy with explaination
This authoritative textbook is intended to provide both a thorough and highly accessible introduction to the cross-disciplinary field of wind engineering. The economic viability and political appeal of wind power is on the increase, making this text a timely addition to the literature. * Developed to complement the increasing number of renewable/wind energy courses now available * End-of-chapter tutorial sections (solutions manual available) * Combines both academic and industrial experience giving the text a dual market appeal * Comprehensive coverage spans every aspect of wind energy engineering

Electromagnetics engineering fundamental
Practicing engineers in diverse fields need to understand how principles can be applied to the solution of real problems. Bridging the gap between standard textbooks and specialized references, Fundamentals of Engineering Electromagnetics builds a foundation in electromagnetics for engineers who need a thorough overview of the subject. Coverage includes applied electrostatics, electromagnetic induction, wave propagation, transmission lines, waveguides and resonators, fundamentals and representative types of antennas, and electromagnetic compatibility. Appendices provide useful constants, units and conversions, and a review of vector analysis and coordinate systems

Electrical engineering dictionary

Fiber reinforced engineering interfaces

Logic controllers programming methods and application - Password=ebooksclub.org

Monday, September 22, 2008

Multi conversions

Multi conversion anything that you want to convert from http://www.unitconversion.org/
with free download tools conversion version 5.1, all you have to do is click below or input.

1. distance and length conversion
2. weight and mass conversion
3. currency conversion
4. capacity and volume conversion
5. volume - dry conversion
6. temperature conversion
7. area conversion
8. pressure conversion
9. energy and work conversion
10. power conversion
11. force conversion
12. time conversion
13.velocity conversion,
14.angle conversion,
15.fuel consumption conversion,
16a.numbers conversion,
16b. data storage conversion,
17.velocity - angular conversion,
18.acceleration conversion,
19.acceleration - angular conversion,
20.density conversion,
21.specific volume conversion,
22.moment of inertia conversion,
23.moment of force conversion,
24.torque conversion,
25.fuel efficiency - mass conversion,
26.fuel efficiency - volume conversion,
27.temperature interval conversion,
28.thermal expansion conversion,
29.thermal resistance conversion,
30.thermal conductivity conversion,
31.specific heat capacity conversion,
32.heat density conversion,
33.heat flux density conversion,
34.heat transfer coefficient conversion,
35a.flow conversion,
35b.flow - mass conversion,
36.flow molar conversion,
37.mass flux density conversion,
38.concentration - molar conversion,
39.concentration - solution conversion,
40.viscosity - dynamic conversion,
41.viscosity - kinematic conversion,
42.surface tension conversion,
43.permeability conversion,
44.sound conversion,
45.luminance conversion,
46.luminous intensity conversion,
47.illumination conversion,
48.digital image resolution conversion,
49.frequency wavelength conversion,
50.charge conversion,
51.linear charge density conversion,
52.surface charge density conversion,
53.volume charge density conversion,
54.current conversion,
55.linear current density conversion,
56.surface current density conversion,
57.electric field strength conversion,
58.electric potential conversion,
59a.electric resistance conversion,
59b. electric resistivity conversion
60a.electric conductance conversion,
60b.electric conductivity conversion
61.electrostatic capacitance conversion,
62.inductance conversion,
63.magnetomotive force conversion,
64.magnetic field strength conversion,
65.magnetic flux conversion,
66.magnetic flux density conversion,
67a. radiation conversion
67b.radiation - activity conversion
68.radiation - exposure conversion
69.radiation - absorbed dose conversion
70.prefixes conversion
71.data transfer conversion
72.EU currency conversion
73.typography conversion
74.volume - lumber conversion

watt [W]:
exawatt [EW]:
petawatt [PW]:
terawatt [TW]:
gigawatt [GW]:
megawatt [MW]:
kilowatt [kW]:
hectowatt [hW]:
dekawatt [daW]:
deciwatt [dW]:
centiwatt [cW]:
milliwatt [mW]:
microwatt [µW]:
nanowatt [nW]:
picowatt [pW]:
femtowatt [fW]:
attowatt [aW]:
horsepower [hp, hp (UK)]:
horsepower (550 ft*lbf/s):
horsepower (metric):
horsepower (boiler):
horsepower (electric):
horsepower (water):
pferdestarke (ps):
Btu (IT)/hour [Btu/h]:
Btu (IT)/minute [Btu/min]:
Btu (IT)/second [Btu/s]:
Btu (th)/hour [Btu (th)/h]:
Btu (th)/minute:
Btu (th)/second [Btu (th)/s]:
MBtu (IT)/hour [MBtu/h]:
MBH:
ton (refrigeration):
kilocalorie (IT)/hour [kcal/h]:
kilocalorie (IT)/minute:
kilocalorie (IT)/second:
kilocalorie (th)/hour:
kilocalorie (th)/minute:
kilocalorie (th)/second:
calorie (IT)/hour [cal/h]:
calorie (IT)/minute [cal/min]:
calorie (IT)/second [cal/s]:
calorie (th)/hour [cal (th)/h]:
calorie (th)/minute:
calorie (th)/second:
foot pound-force/hour:
foot pound-force/minute:
foot pound-force/second:
pound-foot/hour [lbf*ft/h]:
pound-foot/minute:
pound-foot/second [lbf*ft/s]:
erg/second [erg/s]:
kilovolt ampere [kV*A]:
volt ampere [V*A]:
newton meter/second:
joule/second [J/s]:
exajoule/second [EJ/s]:
petajoule/second [PJ/s]:
terajoule/second [TJ/s]:
gigajoule/second [GJ/s]:
megajoule/second [MJ/s]:
kilojoule/second [kJ/s]:
hectojoule/second [hJ/s]:
dekajoule/second [daJ/s]:
decijoule/second [dJ/s]:
centijoule/second [cJ/s]:
millijoule/second [mJ/s]:
microjoule/second [µJ/s]:
nanojoule/second [nJ/s]:
picojoule/second [pJ/s]:
femtojoule/second [fJ/s]:
attojoule/second [aJ/s]:
joule/hour [J/h]:
joule/minute [J/min]:
kilojoule/hour [kJ/h]:
kilojoule/minute [kJ/min]:
power conversion factors provided by unitconversion.org

A dictionary of unit measurement - complete information on a specific unit alphabetical order.

free pdf file for symbol and conversions factors

conversions - mass, length, volume/capacity, area, mass density,linear density, surface density, time, force, energy, heat and work, power.

ampere [A]:
kiloampere [kA]:
milliampere [mA]:
biot [Bi]:
abampere [abA]:
EMU of current:
statampere [stA]:
ESU of current:
CGS e.m. unit:
CGS e.s. unit:
current conversion factors provided by unitconversion.org

volt [V]:
watt/ampere [W/A]:
abvolt [abV]:
EMU of electric potential:
statvolt [stV]:
ESU of electric potential:
electric potential conversion factors provided by unitconversion.org

ohm:
megohm:
microhm:
volt/ampere [V/A]:
reciprocal siemens [1/S]:
abohm:
EMU of resistance:
statohm:
ESU of resistance:
Quantized Hall resistance:
electric resistance conversion factors provided by unitconversion.org

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