0
Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
What is mean by armature reaction?
armature reaction means when load is added to the armature then current is passed through armature conductors then in armature creates flux. It is demagnetize and cross magnetize the main field flux. in other ward it is effect of armature field on main field.
Not adhere to the rules of parallelism for items in a series?
The lawyer ran to the courthouse, was wondering about her case, and eventually decided to eat lunch.
If your dimmer switch goes out will it make your lights not work?
If a dimmer switch goes out, it may cause the lights to not work at all or to stay at a single brightness level. This can be due to a faulty switch or wiring connection. It is important to check the switch and wiring to determine the cause of the issue and resolve it accordingly.
What is the type of switch that reverses the rotation of a single phase motor?
If you are talking about a switch that is used to change the direction that a single phase motor turns from clockwise to counter clockwise, the switch is called a forward - reverse drum switch.
By reversing any two of the three phase legs that feed the 3 phase motor.
<<>>
On a single phase motor a drum switch is used. This switch reverses the start winding so that when voltage is applied to the motor it will revolve in the reverse direction.
The work done by the crane motor can be calculated using the power formula: Power = Work/Time. First, convert the 2.5 tons to kilograms (1 ton = 907.185 kg), then calculate the work done. Next, use the work-energy principle (Work = Force x Distance) to find the vertical height the load is raised (assuming constant speed).
How does an earthing transformer provide a neutral point for delta connected secondary?
There is normally no neutral point for a delta connection, Star or Y connections have grounded neutral points. So earthing transformers (or grounding transformers, GT, as they're called in this part of the world), are used to provide a neutral point in an otherwise ungrounded system. Typically they are found in utility transmission systems, where the grounding transformer provides a path for ground-fault current detection on the phases. The GT is connected in a zig-zag type arrangement such that positive-sequence (phase to phase) current is minimized, while zero-sequence (unbalanced) current presents a low-impedance path to ground. Usually, a reactor or resistor is inserted between the GT neutral connection and ground to limit the fault current to a level which will cause the detection to work but not damage the transmission equipment. See the links below for a simplified connection diagram and a somewhat more complex explanation.
What would 7.5 volts do to a person?
It depends... If the voltage were applied externally, like to fingers or toes, etc. basically nothing. If the voltage were applied to the tongue, you would feel a tingling sensation, nothing more. If it were applied with electrodes inserted through the chest directly to the heart muscle, it could stop your heart, killing you! It's not the volts that cause damage or pain, its the amps. The higher the voltage, the higher the amps. Also, if the electrodes touch moist tissue such as your tongue, the saline moisture conducts better, causing higher current. If the current gets high enough, tissues start to heat, and enough can cause tissue destruction. 7.5 volts is not high enough to do that, given the resistance of human tissue. But, even low current, if it flows through a muscle, can cause the muscle to contract uncontrollably. This is why even a small current through the heart is trouble. Unless you deliver the current directly to the heart muscle, it takes much higher voltage. If you grab an electrode with each hand, for instance, some current would flow through the heart, but because the skin resistance is so high, it takes several dozens of volts before the heart would be endangered.
Are the ground and neutral wires the same circuit?
This is a complicated question to answer accurately. Maybe someone else with enough time available may be able to give a better answer than this one!
For more information on this very interesting topic, please see the answers to the Related Questions and also the much more detailed Related Link whcih you will find below this answer.
In North America, the "neutral" (or "grounded") wire and the grounding (or protective ground) wire are bonded together and connected to a solid Earth ground at a single point in every building electrical service. Obviously at that point, the grounding and neutral wire have the same potential.
At other points, the function of the two wires has to be considered. The neutral is a current carrying conductor, and the grounding wire is not. Since the neutral carries current, there will be some voltage drop between any remote point in the building's wiring and the point where the neutral is bonded to ground, if any current is flowing. This will result in a small potential difference between neutral and ground--usually a few volts at most.
The above is only true if things are working properly. If a neutral wire breaks, then all the neutral connections beyond the break can be at the "hot" wire potential. There are other faults that can cause a "hot" neutral, so it is never safe to assume the neutral is at ground potential.
It is also important to note that the neutral should NEVER be used as a safety ground and vice-versa. I have seen this done: where some incompetent handyman jumpered the neutral wire to the green screw / ground on a receptacle because there was no grounding wire in the box (old two-wire house wiring from before grounding wires were required). Unfortunately another incompetent had switched the hot and neutral someplace, so the result was any appliance plugged into the outlet had a hot metal frame!
What happens if the high and low speed wires are switched on a 3 phase motor?
I am guessing that what you are talking about is a two speed motor. The motor should have 6 wires coming out of it. There are two complete sets of three phase windings for each speed. Look on the motor name plate for the wire numbers or sometimes on the inside of the motor junction box. A 2 speed 6 lead motor should have the following markings, 1U 1V 1W for slow 2U 2V 2W for fast. Also check for the two different amp draws for each winding. These types of motors should be run from a reversing type contactor assemble so that individual overloads can be used on each of the high speed windings and on the low speed windings.
This information can be found in the latest edition of the NEC. A calculator that I like to use is below in Related Links. Note that the NEC (National Electric Code) tables are usually adopted in the US. Since your question is in SI units (meters), you are probably outside the US. Be aware that your local electrical code may be more stringent than the NEC, or have different requirements. Best to consult a local professional or research what standards are adopted in your area! Be legal, be safe! IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS. If you do this work yourself, always turn off the power at the breaker box/fuse panel BEFORE you attempt to do any work AND always use a meter or voltage indicator
to insure the circuit is, in fact, de-energized.
The phase angle between voltage and current in an a c circuit through a pure capacitance is?
90 degrees. In an AC circuit with a pure capacitance, the current leads the voltage by 90 degrees. This is because the current in a capacitor is proportional to the rate of change of voltage across it, leading to this phase relationship.
Do your own homework.
^^^^^^^^^^
I'm pretty sure that if this user wanted a smart remark like yours he wouldn't have posted the question, this website's name is "answers.com" not "smart remarks made by people who have no lives and suck at life.com" thank you. I wish you luck getting the correct answer.
Ditto....this person has nothing else better to do
How many megawatts would be needed to supply 1 million kilowatt hours?
A 1 MW generator produces 1000 KWH every hour assuming its fully loaded. There are 8760 hours in a year, so assuming no downtime, it would generate 8,760,000 KWH in a year. 1MW = 1000000 watts 1 KW = 1000 watts 1 MW = 1000 KW 1 MW for 1 hour = 1 MWH 1 MWH = 1000 KWH
What is that charging a neutral object by bringing it close to a charging object?
Charging a neutral object by bringing it close to a charged object is known as charging by induction. When a charged object is brought near a neutral object, the charges in the neutral object are rearranged, causing one side to become oppositely charged to the charged object, resulting in an overall charge on the neutral object.
What is thermodynamic equilibrium in physics?
Thermodynamic equilibrium is a state in which a system is not experiencing any net change in its macroscopic properties over time. In this state, the system's temperature, pressure, and other relevant variables are uniform and do not exhibit any gradients. This concept is important in understanding the behavior of systems in thermodynamics.
Generally no. The purpose of an arc fault breaker is to kill a circuit if water or any other type of element were to intrude the branch to prevent an arc fault blast. They can go bad over wear and tear over time and if not used properly or if the neutral becomes to short to reach the neutral bar or if an arc fault blast occurs the breaker will go bad ofcourse.
V=IR
To calculate your voltage drop (V), you multiply your resistance (R, measured in Ohms) and current (I, measured in Amps [A]) by each other the. The number you are left with should be your voltage drop.
Yes, the efficiency increases. Yes, it is linear. Power lost in a current-carrying conductor is: P = I^2 * R So, if you halve the resistance, you halve the power loss. Note though that the current (I) term is squared. So if you can decrease the current by increasing the transmission voltage, the increase in efficiency is not linear, but exponential! Halve the current (and double the voltage to get the same power), and you reduce losses by four times! This is why utilities use such high voltages for transmission. Superconductors are no different, you are still talking about a reduction in resistance, superconductors just achieve a much lower resistance than a standard conductor. The question is whether the cost of superconductors and their cooling systems (currently very high) outweigh the modest gain in transmission efficiency.
What is an electrical three line diagram?
An electrical three line diagram is a simplified representation of a three-phase power system showing the interconnection of power system components using lines to represent conductors. It is commonly used by engineers to quickly understand the configuration and operation of complex electrical systems.
You didn't specify the voltage that you are using but here is a simple easy to read chart that may meet your needs:
http://www.fennelfamily.com/gti-vr6/electrical/cable-length.html
You can google "wire gauge distance" for more charts. Be careful and good luck!
What is the equivalent resistance through the entire circuit?
The equivalent resistance is the overall effect all of the resistances in a circuit has. Put another way, it is the value a single resistor in a circuit would have to be in order to have the same effect as all of the resistors resistors combined in a given circuit.
What you basically want is will each phase take 26 Amps current for 15HP 3 phase 415VAC motor?
Yes, for a 15HP 3-phase 415V AC motor, each phase will draw approximately 26 Amps of current when running under normal operating conditions. This results in a total current draw of 26 Amps per phase for the motor.
What do you call a fuse with two black wires attached?
A fuse with two black wires attached is typically called a "black wire fuse." The black wires serve as the connections for the electrical circuit, with the fuse serving to protect the circuit from overloading or short circuits.
Why phase displacement is maintained between primary and secondary windings of the transformer?
Maintaining a phase displacement between the primary and secondary windings of a transformer allows for the effective transfer of power from the primary to the secondary circuit. This phase difference ensures that the magnetic flux induced in the primary winding can generate a voltage in the secondary winding, enabling power to be transmitted efficiently and accurately between the two circuits.
False. The total current in a parallel sub-circuit where all resistors have the same value cannot be found by multiplying the current by the number of resistors. In a parallel circuit, the total current depends on the individual resistor values and how they affect the overall resistance of the circuit.
