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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 do you determine no load current and core loss of a single phase transformer?
It's easily done if you can measure the power drawn at the normal working voltage but with no load on the transformer (open-circuit secondary). All the power is core loss with the exception of a (very) small amount of resistive loss in the primary winding.
Arc-fault circuit interrupter trouble shootting?
The test is, push the button, if the breaker trips, tested ok, if not,the breaker is bad,(rare)
or if it does not reset, somewhere in the house, hot is connecting to neutral. Bad outlet or even light fixture.
Arc-fault are used in bedrooms. Codes in most areas. These are in case the kids stick a fork into an outlet.
Ground fault is used near water.
the white wire is your neutral side (ground usually), the small potential you're measuring is bleed current
Is a current relay same as potential relay?
current relay are using for over current low state & high state.but potential relay are related to voltage.
Horn gaps in 315 mva power transformer?
I assume that you are asking what is the separation of a horn gap? Horn gaps are determined by voltage levels, not by power levels, so your question cannot be answered.
On the other hand, if you are asking what they are for, then its to divert travelling voltage waves (due, for example, to lightning strikes) to earth before they can damage the transformer.
Incidentally, if you mean 'megavolt amperes', rather than 'millivolt amperes', then your question should read '315 MV.A', not '315 mva'!
When is a motor in star or delta connection?
Star (or wye) connection is where each of the three phases has a fourth conductor, neutral, as its current return. Current flow in this configuration is phase to neutral, which is also grounded back at the distribution center. There will be five total connections, phase A, B, and C, neutral, and (protective earth) ground.
Delta connection is where each of the three phases uses the prior phase as its current return. Current flow in this configuration is phase to phase, and there is no neutral, though there is still a ground. There will be four total connections, phase A, B, and C, and (protective earth) ground.
Where can self winding watches be bought?
Self winding watches have been around for many years. Any leading jeweler will carry different brands. Kay Jewelers, Zales, Jarrod Galleria, and The Jewel Box all have them.
Why should civil engineers study basic electrical engineering?
It's been about 60 years since I was in engineering school but at that time civil engineers were not required to take any electrical engineering courses.
What is the voltage used in submarine cable?
Submarine power cables work on voltages of 400 kV or more, often with DC because they are linking power grids that are not synchronised.
Submarine communications cables now work with fibre-optics so the signals are modulated light-waves.
Additional Answer
Further to the original answer, another reason for using direct current for submarine cables is to eliminate capacitive currents that would flow if a.c. were used instead. The closeness of the submarine-cable's cores results in relatively-high levels of capacitance between each core and, with a.c., this would represent a capacitive load resulting in a continuous capacitive current along the cable. Such currents flow in all underground a.c. cables but, due to the length of most submarine cables, the capacitive current can be unnecessarily high.
The switch on the back is the switch for the power supply only. The computer boots from the main power switch on the front. This particular method of switching was introduced with the ATX power supplies.
Can you build a Joseph Newman motor using AC instead of DC and how?
Probably not. For more information click on the Related Link shown below.
What type of primary circuit is used when lighting makes up the substantial portion of the load?
In the US most residential an a fair amount of commercial lighting is done with 110 volt 15 or 20 amp Alternating Current (AC) curcits.
A large amount of office lighting is done with 277 volt 15 amp ac curcits. Some is done with 240 volt ac and some with 480 volt ac, but these ar usually in industrial or large area applications.
There is also 208 and other source power applications but these are rarer still.
LED, Florecent and other types of lighting is supplied through transformers with various voltages from 2 or 3 volts up to 10 or 15000 volts at very low amprages.
The general rule is to accomplish the lighting requirements with the most efective and efficent possible amps and curcits based on the available power supply scource.
Terry
Combination building inspector
Just because you get a good voltage reading at the PCM, and are still getting that OBD II code, doesn't necessarily mean that the TPS is still bad. The Signal wire running from the TPS to the PCM is a straight shot, but the ground wire and the reference wire have a few splices in between the TPS and the PCM. Make sure to check the voltage at all those different spots. If you get a good reading on the voltage at all the different points on those wires, then it could be that you just bought a bad TPS. One way to check, it to take the TPS off, but leave it connected to the wiring harness. With the voltmeter leads on the ground wire and the signal wire, and the key in the ignition and turned to the on position (engine still off), manually manipulate the rotating slot and you should see a nice gradual increase in voltage. If not then that's a bad TPS. Hope this helps.
Calculate three phase watts with unbalanced load?
Power can be calculated in each individual phase and summed together. If the voltage is supplied L-N in RMS: P = V*I. Note this will give the same answer as calculating balanced three phase power from the equation P = V*I*sqrt(3)
yes open all fuses close the primary neutral tap,remove secondary leads off of bad traansformer,tell customer to reduce his load until bad transformer can be replced.
High voltage gloves, also known a gauntlets, are gloves worn by utility line men. There are two parts to the gloves. The inner pair are made of a high dielectric rubber numbered from 00 to #4 which covers voltage ranges from 500 to 36000 volts. The outer pair are made of leather. They are used to stop perforation and scratch cuts of the inner gloves from wires end perforation. Before the gloves are used they have to be tested by the person that is using them. Every year they have to be sent to a testing laboratory to be tested with high voltage to make sure that they still maintain their voltage insulation number rating. If the gloves fail this test the gloves are destroyed and new ones have to be purchased. These gloves are for line men safety and are worn even when the high voltage system is de energized.
Is a 3 phase motor a Synchronous motor?
A synchronous motor can be a type of 3-Phase AC motor, or not.
A synchronous motor is defined by the period of the rotor being synchronized with the frequency of the stator windings' current. The stator windings might be 3-Phase or not (2-Phase would work).
Also synchronous motors are not the only type of 3-Phase AC motors. An induction motor could also be 3-Phase AC and has a few advantages and disadvantages over a synchronous motor.
Is it common to use a 4160 V 3 Phase motor with a variable speed drive?
No, a 4160 volt motor with a high inertia load will use a resistor bank in the starting of the motor.
