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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
NO! NO! NO! The circuit breaker must be rated for the line voltage used. Exceeding this limit can cause catastrophic failure! If you are really working on a 1600A bus, stop right now, ang go hire a professional! Your question indicates you are not qualified to work on this gear. YOU ARE GOING TO KILL SOMEBODY. I'm not kidding about this. A breaker that is applied beyond its rating can arc over, and the resulting arc-flash can punch right through the panel cover, spraying vaporized metal on anyone unfortunate enough to be standing there. A 1600A bus can have a fault current of 20,000A OR MORE. This is not something to even think about working on unless you are trained and absolutely know what you are doing!
What is a regenerative variable frequency drive?
Its is a type of Variable frequency drive which uses concept of dynamic braking to generate a feeding back power , once the brakes are applied to a electric motor , the energy is usually dissipated as heat inside the electric motor in all the regular VFD's but instead this Regenerative unit passes on this energy into a resistor , from which it is converted into electricity, which is of fen fed back to the system , resulting huge power saving , but this also depends on the load and the number of time brakes are used in an application ,
this is of fen called in different names like Regenerative AC drives, Regenerative VFD'S (in short form)
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Same note played on two different instruments different?
Usually the way you play the notes are different. so the answer would be yes the note is different.
An impedance triangle has resistance (always positive) in the x axis and reactance (at a right angle to resistance) in the y axis. The line that completes this triangle (the hypotenuse) is the absolute value of the impedance.
How can you determine the difference between an AC or DC electric motor?
Direct current or DC electric motors work for situations where speed needs to be controlled. DC motors have a stable and continuous current. DC motors were the first and earliest motors used. They were found, however, to not be as good at producing power over long lengths. Electric companies found using DC motors to generate electric did not work because the power was lost as the electric was transmitted. Brush DC motors use rings that conduct the current and form the magnetic drive that powers the rotor. Brushless DC motors use a switch to produce the magnetic drive that powers the rotor. Direct current motors are often found in appliances around the home. Alternating current or AC electric motors are used differently based on what type of AC motor it is. Single phase AC motors are known as general purpose motors. They work well in many different situations. These AC motors work great for systems that are hard to start because they need a lot of power up front. Three phase, also called polyphase, AC motors are usually found in industrial settings. These motors also have high starting power built transmit lower levels of overall power. AC power gets its name from the fact that it alternates in power. The amount of power given off by an AC motor is determined by the amount of power needed to operate the system. gary
DC motors are of mainly 3 types.series motors, shunt motors, and compound motors. DC motors are mainly used where high torque is required from less speed (rpm),and a constant rpm can be maintained.
Used mainly in : lathe ,drill machines, grinding machines, compressors and so on.
Ac machines have less expenses. Used widely because Ac is more popular. They have less torque on slow speeds.
Used on cooling fans, water pumps etc.
Circuits need 3 things to work. They need a load, (what the power goes on) power source, (the battery) and connectors (the wire inbetween). Circuits use electrons to flow from the negative side of the battery and around the circuit back to the battery. This repeats until the circuit breaks.
Why high voltage transformers have graded insulation?
It is to decrease the amt of insullation materials used. It can be used only for star connection.
Answer'Graded insulation' is all about controlling the shape of the electric field within the insulator to prevent breakdown due to local peaks in potential difference across that insulation.
Operation of on load tap changer in transformers?
OLTC - INSTALLED IN THE PRIMARY SIDE OF A POWER TRANSFORMER TO SELECT OR ADJUST VOLTAGE. THE ADVANTAGE OF THIS IS FOR SOLVING THE VOLTAGE DROP ISSUES IN THE SECONDARY OUTPUT IN THE FARTHEST LOCATION. FOR EXAMPLE YOUR SECONDARY VOLTAGE REQUIREMENT IS 380 VOLTS AND YOU CAN ADJUST TO 400 VOLTS FOR LONG CABLE RUNS.
Is it possible to build a fire proof building?
No. You can help fire proof a building. But there is always a chance it can catch on fire somehow. Fire sprinklers are only used to keep the fire under control so it doesn't spread...they are not used to put the fire entirely out. Firefighters are for that. Anything that you use to fire proof a building is only used to keep the fire under control until the Firefighters arrive.
The closest you can get to a fireproof building is a brick one with a terracotta tile roof.
What is the principle of operation of gang capacitors?
Gang capacitors are a series of capacitors that are mounted to a common location. When they are mounted in series, they can be controlled by a single switch instead of multiple ones.
What is the current density formula?
J = ρ.u
Where
J = Current Density (Ampere per meter square) ρ = Charge Density (Coulombs per cubic meter) u = Particles average drift velocity (meters per second)
http://www.etap.com/faqs.htm
How do you calculate the multiplication factor of energy meters?
Look for the ct (current transformer). You will find a ratio rating (for example, 200:5.) This means divide 200 by 5. The result is 40. Any difference in reading from a certain time should be multiplied by 40 to get actual energy consumption. This is the basic information, but in practice it should be calibrated by a government-certified body (the department of energy, for example) to perfectly match the kwhr-meter revolution.
What is meant by proximity effect in transmission line?
Assume the AC currents are going in opposite (SAME) directions in a twin pair transmission line. The magnetic fields so created have the effect of forcing the current flow towards the centre (OUTSIDE). The effect is greater with higher frequency. As the copper is not being effectively utilised, the resistance goes up. This effect is distinct from "skin effect". The effect is also greatest if the gap between wires is small. Unfortunately, as of April 2009 an on-line calculator is difficult to find.
Is it safe to connect a 4 speakers to a 4 ohm amp?
First, you must know: There is no 4 ohm amplifier. All audio amplifiers have an output impedance of smaller than 0.5 ohms. So you use impedance bridging. No problem to connect the 0.5 ohm output to your 4 ohm loudspeaker. Scroll down to related links and look at "Impedance bridging - Wikipedia".
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Contact HSS academy for the same. This the best institute in India. It is located in NOIDA. They are openong more branches in the country. www.hssacademy.com The head institute
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What do you mean by Dynamic and transient behavior of diode?
A diode is characterised by its static transfer function, i.e. the I/V curve for forward and backward volts, how the junction capacitance varies with reverse voltage.How the temeprature varies with power. But the dynamic behavior of diodes is expressed by the response to steep edges at turn on (i.e the length of delay in current turning on in response to forward volts) and turn off (how long before the charge carriers are all swept out of the diode junction and it is turned off.)
Definition of coil in contactor?
The coil in a "Contactor" is essentially an electromagnetic coil that provides the driving force to close the contacts in a Contactor. When the "Coil" is energized by a lower control voltage usually from some type of controller such as a PLC, the Normally-Open contactor will close or in the oposite case, the Normally-Closed contactor will open.
How do you amplify DC voltage?
Either electronically through a DC Bus similar to what is used in a Variable Frequency Drive, or through a Voltage doubler where resistors in parallel with a series r off of the p resistor acts as a voltage multiplier. Search for Voltage divider, or DC amplifier.
What is the working principle of electronic dimmers?
Electric dimmers work basically by controlling the amount of voltage going through. It chops out portions of the current, and the reduced voltage reduces the power of the receiving device, usually a light.
What is the differences between the slip and split rings?
Split rings are in AC generators ( alternating current) while slip rings are in DC current (direct current).
Why windings of a direct current motor are made of copper?
Copper is the best base metal for conducting electricity. Gold and silver are better but too expensive.
If you used a poorer metal you would lose more power and it would also generate more heat which in a motor would be quite a lot. More heat would then cause more resistance which would cause more heat.
What are the various types of filters that are employed in HVDC converter station?
There are various types of filters that are employed in HVDC converter station. These include high-voltage direct current and terminal stations.
What is the difference between busbar and busbar trunking system?
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