Electrical Engineering

A phase current is the current passing through a phase, whereas a line current is the current flowing through a line.

volts times amps equals watts, a measure of power. Amps times hours equals amp-hours, a measure of electric charge. Electric charge times voltage is energy.

So 120 volts at 10 amps for 4 hours would pass 40 amp-hours of charge, the power would be 1200 watts and the energy would be 4800 watt-hours or 4.8 kilowatt-hours.

So volts times amp-hours equals energy in watt-hours.

Most do, but not all. Some have a separate exciter winding.

A voltmeter must have a very high resistance to measure voltage. A voltmeter is placed in parallel with the element that you are measuring. If the voltmeter has a low internal resistance, then all of the current will flow through the voltmeter instead of the element. You want all of the current to flow through the element, to get an accurate reading of the voltage.

Conversely, an ampmeter must have zero resistance, because it is placed in series with the element.

If it were less than a number of Megohms it would not be insulation.

208V is one standard in the US for light commercial 3-phase power. It measures 208V phase to phase and 120V phase to neutral. 230 (or 240)V refers (in the US) to the common service supplied to residential. It is single-phase, with two hots and a neutral; 120-0-120. One hot and the neutral (120V) is used for receptacles and small appliances, both hots (240V) are used for large appliances, such as stoves, ovens, air conditioning, and water heater.

Circulating fluidised bed combustion

I also have the same question. After some research, I understand that you cant just jump in and calculate this. You have to have alot of information about that spesific generator. I have found out that you can use some formulas from losses in transfomers.

The bandwidth of a signal is the width of frequencies between the highest and the lowest frequency.

So 500Hz - 50Hz = 450Hz bandwidth.

AE7HD

2 wire.3 wire nd 4 wire...rtd...

3 wire rtd is widly used....hv good accuracy...

This mainly depends on your motorsize, characteristics,applications,according to the sitedesign, there are die casting aluminum, cast aluminum, cast iron andgray cast iron andductile ironcasting

Materials, aluminum, cast iron( gray iron and ductile iron are very common),steel plate and so on can do stand.

Pressingstator, a thermalsleeve having cold after being tightened screws fixed, weldingand so on, but also all kinds of method to have.

The base is generally divided into: box, shell and the core shell casting

In 1, a boxwith steel plate welding, short cycle,low cost, no standard, no need.

2 casting shell are generally used for small motor.The majority to iron.

Aluminum motor shell in general use thermal cover,glue, screws, iron general directly press,screw fastening

A potentiometer.

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The core of the armature consists of thin metal plates instead of a single piece. The thickness of the laminations depends on the frequency of supply. They are approximately 0.5mm thick. For the armature core, laminated silicon steel is used to reduce eddy currents and hysteresis losses

cos it's a plot it needs to be called a plot

Transformation are nothing but changing the image in to different forms by

1)scaling

2)translation

3)rotation

scaling:increasing the size of the actual image

translation:moving image from one position to another position

rotation:changing the angle of image

and yaw

I work for National Instruments. NI is one of the companies that defined PXI. PXI stands for PCI eXtensions for Instrumentation. It is like the PCI bus, but extended. This means that extra connections are available to share signals between multiple PXI peripherals.

SCXI stands for Signal Conditioning eXtensions for Instrumentation. Signal Conditioning is the general term for the process of making a signal more useful by improving its precision, accuracy, or signal-to-noise ratio.

Think about a sensor/transducer such as a thermocouple. In order to get quality temperature readings, you need to amplify the thermocouple signal. You should also filter out high frequencies, because while noise is high-frequency in most environments, temperature changes almost always happen very slowly.

SCXI can also handle switching, and has some multiplexer's in the background so that a separate ADC can capture the conditioned signals.

So, to put these two together, a real-world signal from a transducer goes into SCXI, which might then send the conditioned signal into a DAQ board in a PXI system.

Another key difference is that a PXI bus directly communicates to an operating system on a computer, while SCXI only does things to signals and passes them on to DAQ devices.

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IS ISMILAR

TO THE GROUND RESITOR

CALCULATION FOR TRANSFOMER

THE TYPICAL EXAMPLE WAS ANSWERED EARLIER FOR TRANSFORMER DT.19-06-2009

Neutral of transformer can be grounded solidly earthed OR with Neutral Grounded with Resistance.

Typical shunt calculations fro 5 MAV 11/6.6 kv

transformer neutral are as :_

Transformer rating =

5 MVA

Voltage ratio =

11/6.6 KV

Vector Group =

Dyn11 (6.6 KV ground through Resistor)

During Earth fault voltage between Neutral & Earth =

6.6/√3 =

3.81 KV

Earth Fault current will be limited to =

5 x 10³ /(√3 x 6.6) =

437.38Amp.

N.G.R.

value in ohm =

V / I =

(3.81 x 10³) / 437.38 =

8.71 Ohm

Value of N.G.R.

is 437.38 Amp, 8.71 Ohm., 10 Sec

NGR are inserted On Higher voltage to restrict earth fault current

BY

SRI

these instrument are widely used in laboratories and switch boards at commercial frequencies because these are cheaper in cost , robust in construction and can be manufactured with required accuracy.

there are two general types of such instrument i.e (i) the attraction type (ii) the repulsion type . the attraction type instrument operate on the principle of repulsion of two adjacent iron piece magnetised by the same magnetic field. repulsion type instrument are are more sensitive as in these instrument large operating torque is developed by having two iron element positioned close together inside the field coil where the magnetizing effect is maximum. in both type of these instrument the current under measurement is passed through a coil of wire. this current carrying coil sets up the necessary field. depending on the magnitude of the current to be measured the coil may be of a few turns of very heavy conductor or of many turns of fine wire. the instrument to be used as an ammeter is provided with a coil of thick wire in order to have low resistance and carry large current and to be used as a voltmeter is provided with a coil of large number of turns of fine wire in order to have high resistance and draws as small current as possible.

A transformer or, more-properly, a mutual transformer, has two windings, the primary and the secondary, which are electrically-isolated from each other, with the secondary voltage induced through mutual induction. An autotransformerconsists of one tapped winding, so the secondary circuit is not electrically isolated from the primary circuit. An autotransformer may be used to either increase or decrease the primary voltage, depending how it is connected.

because our system form factor is 1.1

When is the result of diploma which held in october 2008?

How Negative phase sequence relay work

good question