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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
How can the power output of generators be coupled?
Generally speaking, the outputs of generators can be coupled by connecting the generators in parallel. In generators that produce DC (direct current), the voltages need to be equalized and the polarities of the connections needs to be observed. Both negatives are connected together and both positives connected together to create one parallel output. In an AC setup, the generators need to be running about the same voltage, and must be connected in phase for the setup to be successful. In practice, the generator that is being brought online is run up, and it frequency is allow to be a little bit faster than the unit that is online. When the phase difference is being observed, and the difference is approaching zero, at a "couple of degrees before" the zero, the generator that is being brought online is then connected to the grid and it "locks in" so that all the generators are running in phase. Connecting DC generators positive to negative is an invitation to disaster, and bringing an AC generator online 180 degrees out of phase with an running generator is the same kind of disaster. Shutting a breaker to parallel generators without insuring polarity concordance (in the case of the DC ones) or phase concordance (in the case of the AC ones) will pit one generator against the other, and severe damage will result.
What are the disadvantage and advantage of dry type transformer?
Advantages dry type transformer accommodates less place than any other.
this x'mer do not catches a fire.
instalation at any place is convenient.
eco friendly looks & use
internal inspection is possible.
no corrosion.
side clearance is less
maintenance free (easy)
disadvantages
can not be use for more than 2000KVA
How do you calculate total power in parallel?
Either (1) determine the power of each branch, and add them together, or (2) multiply the load current by the supply voltage.
Can you run a 240 volt pump with a generator that when idling puts out 260 volts?
It will probably be OK but if you are worried about it why not check with the User's Manual for the Pump to see if it mentions what tolerance of voltage fluctuation it has.
Normal household AC voltage fluctuation in US, Canada and countries which use similar 60 Hz supplies, can be 240 volts RMS +/- 10%, that is from 216 Volts to 264 Volts.
In Europe the standard frequency is 50Hz and the voltage specifications are now 230 Volts RMS +10%/-6%, that is from 216.2 Volts to 253 Volts.
What is the color of a phase conductor?
well that all depends when your dealing with what voltage is being applied to your motor,home, or building. the phase conductor in A panel box can be labeled with either red, or blue tape meaning that's the phase conductor or hot. This all comes down to with what type of electrical equipment or service your working with, The word phase just means that's the hot side and the hot side is usually the black wire, although a red or blue wire can to. Plus a wire being the hot conductor, or load the NEC likes to call it the phase conductor.
CommentThe term 'phase' conductor, in this context, is incorrect. The correct term is 'line' conductor.
Why the armature current is increasing when the terminal voltage is decreasing?
I did of enginearing pleace help me of you
Why transposition required of low voltage power transformer winding?
It is to reduce circulating current losses on winding.
You should study up on Kirchov's Current Law (KCL). It is the means of answering your question and a tool for understanding all parallel circuit configurations.
AnswerKirchhoff's current law will tell you that the supply current is equal to the sum of the branch currents.
How do you work out amps of current from 230V connected to 534 ohm resister?
you divide the volts by the ohms
How do you produce a current in a circuit without a voltage source?
A: mathematically speaking at zero potential with an infinite current source there should be current. PARADOX go around the world except go half way stop divide the distance and so forth mathematically there is going to be no end to the travel.
ANSWER: Current will only flow if it find a path to flow. POTENTIAL for volts can exist without current flow. As soon as we try to measure it current will flow.
BS7671:2008, Requirements for Electrical Installations, defines the design current (of a circuit) as 'the magnitude of the current (rms value for a.c.) to be carried by the circuit in normal service'.
Where can you find choke tubes for an Ithaca MAG 10?
ur gun was made after 1986,may wanna try old western scrounger on the net
Does the sharper image air purifier work?
The Sharper Image purifier uses negative ions that cling to dust particles, dragging them to the ground. What this means to you is that you are not cleaning the air, only temporarily putting the dust in "time out". I recommend something with a hepa filter, activated carbon, and UV to kill bacteria. Check out http://www.sterilairpurifiers.com.
Who discovered the motor principle?
Basically all the motors run by "Electromagnetic induction" principle which was set by Michael Faraday.This principle also known as "Faradays law of electromagnetic induction".
On a toaster which switch opens and closes the circuit?
There is a main switch to turn it on and off which, on some makes of toaster, is operated when the bread-carrier tray is moved into the "toasting" position. On some other makes of toaster the main switch is operated when the toast color control is operated, usually by turning a knob or sliding a slider.
Depending on the make of toaster this "browning level" control either sets a particular "toasting time" or a particular "color". In either case, when the toast is done - meaning when the temperature has reached the manually-set point - a thermal switch shuts off the current to help prevent the toast from burning.
For safety reasons, to help prevent starting house fires, on modern toasters there is also a second, high-temperature, thermal switch. This is designed to shut off the current if the temperature gets so hot that the toaster could burn not only the toast but also nearby surfaces such as the worktop or table it is standing on, a wooden cupboard, curtain, etc. Can't have toaster heating up the room!
What is maintenance in telecoms equipment?
Is to check periodiccaly,I am guessing. I suggest you check out the link i have attached for your reference.
When we look at transformers, we'll generally see that watts in will equal watts out. Said another way, volt-amps in equal volt-amps out. There is a simple relationship between the turns ratio between the primary and secondary and the voltages between those two windings. From there, it's a hop, skip and a jump to figuring out currents. In a one to one transformer, volts in equal volts out. Current in will equal current out, too. Watts in will equal watts out. In a step down transformer with, say, a 10:1 ratio, 120 volts in will produce 12 volts out. And a 1 amp secondary current will appear as a 0.1 amp current in the primary. The 120 volts x 0.1 amps = 12 watts. And the 12 volts x 1 amp = 12 watts. Volt amps in equals volt-amps out, and power in equals power out. Simple and easy. If you are using a step up transformer in, say, a 110 volt to 220 volt application, 110 watts in the primary at the 110 volts will be 1 amp. In the secondary side, 220 volts will appear and 0.5 amps will be the current flow. The 220 volts times the 0.5 amps is 110 watts, as asked about. The secondary has twice the voltage and half the current of the primary side. There are 110 watts in and 110 watts out. Again, simple and easy.
You would need an inverter
http://en.wikipedia.org/wiki/Inverter_%28electrical%29
Why is an electrical fuse burnt?
An electrical fuse would look "burnt" if something in the circuit it is protecting has developed a fault which caused a current overload situation to occur.
In other words, something caused the current flowing through the fuse to exceed its normal rated maximum current value so much that the fuse did what it was designed to do!
In this situation, if a new fuse of the same value immediately blows, do not attempt to replace it by a fuse having a higher rated current value. The correct procedure is to find out what went wrong in the circuit that the fuse is protecting and then get the problem fixed so that the equipment works properly again without blowing a new fuse having the same rated current value as the original fuse which looked burnt.
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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
Why elevators run on direct current?
One of the requirements of an elevator is high speed between floors, but a slow speed as it approached the floor, so that the floor levels are accurately aligned.
This is easy to organize with a DC motor.
When wiring up a 3 phrase motor what do you do if the motor rotates in the wrong direction?
Reverse the connection to any two of the three line conductors.
