Electrical Engineering

DC ground refers to a reference point in an electrical circuit that is considered to have a zero voltage level, typically used for direct current (DC) systems. It serves as a common return path for electric current, ensuring stability and safety within the circuit. In many applications, DC ground is connected to the physical ground (earth), helping to protect against electrical faults and providing a reference for circuit measurements.

600v is a three phase service, where 347v is the L-N voltage (if grounded).

Assuming the question is about simple reactive control gear, e.g. a choke or inductor in series with the discharge lamp, then the following answer applies.

In an ideal situation, an ideal inductor, that is an inductor exhibiting pure inductance by virtue of its construction and the use of wire with no resistance, then the losses would be zero and the power consumed by the circuit would be V.I.Cos Phi, where Phi is the phase angle between the voltage and current.

In the real world electronic components are rarely ever perfect, and although a component may be called an inductor or choke, it will possess some parasitic resistance and possibly some stray capacitance too. The main source of the parasitic resistance is due to the resistance of the wire used to wind it, the diameter and length of the wire required to obtain a particular inductance and current rating and any eddy-current losses in an iron core if one is used. In the case of street lighting control gear designed to function at 50 or 60Hz, laminated iron cores are almost always used to obtain the relatively large inductances required. (At 240v R.M.S., 50Hz approximately 1 Henry of inductance is required to regulate a 20 Watt discharge lamp and 100mH for 200Watt lamp and 10mH for a 2Kw lamp, particular lamp types such as fluorescent, high pressure sodium or metal halide of the same power rating requiring slightly differing inductance values dependent on their discharge voltages at their specified operating currents.) The laminated iron cores are often constructed with an air gap to control the current value at which the core saturates.

In a real choke power is wasted in I squared R losses in the parasitic resistance of the wire, which appears as a low value, (hundreds of ohms for low current, high inductance chokes down to a an ohm or less for high current low inductance chokes used for large H.I.D. lamps) in series with the actual reactive inductance obtained by the number of turns, thickness of the wire and the nature of the core. Eddy current losses appear as a parallel resistance across the series combination of the actual inductance and resistance of the wire. Both of these resistive components add a small in-phase current to the large lagging current of the inductive component. (An ideal inductor exhibits a pure quadrature lagging current.) The series resistive component due to the wire is easy to measure and can simply be measured with a multi-meter on the appropriate resistance range for relatively high inductance chokes used with lamps up to about 400w rating. A four wire milli-ohm meter may be needed to measure the lower resistances of "larger" , lower inductance chokes with fewer turns of thicker wire, used with lamps rated above 400w.

Simply measuring the operating current, squaring it and multiplying this by the previously measured resistance will give the loss in the choke due to its wire resistance, but this will not include any eddy current losses in the core. Another method would be to connect the choke directly across a low source impedance A.C. voltage of the intended operating frequency. Generally most series regulating discharge lamp chokes can be connected directly across the supply voltage they are intended to be used from, (lamp shorted out), although some may saturate and in this case the voltage would need to be reduced. Under these conditions one could use a low value shunt or a suitably terminated current transformer in series with the choke under test to obtain the current waveform on an oscilloscope. The voltage waveform across the choke could also be displayed on the second channel of the oscilloscope to give both the amplitudes and phase angle between the voltage an current. Rembering to take into account the ratios of the current and voltage transformers used and to convert the peak values to R.M.S., the in-phase component should be able to be extracted by resolving the phase ange and magnitudes from the oscilloscope into two orthogonal components. The magnitude of this in-phase component of choke current can be used to calculate all the lossy resistive components, Rt, of a real choke and thus using "Iop" squared "Rt" to get the trus losses. ("Iop", being the operating current through the choke when used with a fully run-up lamp in series.)

Some notes, low inductance, high current chokes wound on large cores with few turns of thick wire and used for H.I.D. lamps with power ratings of aroud 1Kw or more are a lot less lossy than high inductance, low current chokes used for small fluorescent tubes which are wound with many thousands of turns of fine wire with high resistance. High frequency control gear, such as that used in electronic compact fluorescent lamps. operating at frequencies of around 45-50KHz make use of the fact that inductive reactence = 2pifL, and by increasing the frequency, f, the inductance, L, can be reduced by an inverse amount and since the inductance, L, is roughly proportional to the number of turns, these can be reduced requiring a lot less wire and thus possessing a lot less resistance and thus are a lot less lossy. The losses in the rectifier and oscillator used to raise the frequency are more than compensated for by the large increase in inductance.

Measuring omic "I squared R" losses in control gear such as leak transformers and "constant wattage", CWA gear is more demanding but not impossible.

Rtotal = 1 / ( (1/RA) + (1/RB) )

1) in inductor there is generation of magnetic field due to flow of current . so there is phase difference in voltage and current .

2)in capacitor there is storage of charges. there is phase diff.

3)But in case of resistor there is no such things are happend . it is only a power dissipating element.therefor there is no phase difference between current and voltage.

It can overspeed.

eşşeğin siki bizde bunu arıyorduk

Thermal conductivity in a substance relies on the collisions of the molecules within the substance to impart the vibrational, rotational and/or kinetic energy of one molecule to another molecule. Because the molecules in a gas are (usually) much more widely spaced than in a liquid or solid, the collisions are less frequent and it takes longer for the energy to propagate through the volume occupied by the gas. There is also the matter that because there are fewer molecules in a given volume of gas - compared to if a liquid of solid were occupying the space - there are fewer molecules impacting the heat source and the heat sink - consequently a gas is slower to pick up the heat energy from the source and transfer it to the sink. A third factor is that because gases are less dense than liquids or solids, they have a much lower heat capacity than those denser phases. The lower heat capacity acts somewhat to throttle the rate at which heat can be transferred.

A flow of charge is called a current. It is measured in coulombs per second per amperes.

In induction motors no seprate source is required to start the motor,and motor itself induces emf as the word induction clearly reflects it starting principle while in case of synchronous motors ,motor is synchronised with an external source of emf.

Examination leakage typically occurs due to a combination of factors, including inadequate security measures, lack of proper supervision, and the unethical behavior of individuals involved in the examination process. This can involve students, teachers, or administrative staff who might intentionally share exam content or answers. Additionally, reliance on digital formats without robust cybersecurity protocols can lead to unauthorized access and distribution of examination materials. Ultimately, systemic vulnerabilities and a culture that does not prioritize academic integrity contribute significantly to this issue.

1000

All transformers are AC. Your question also does not contain enough information. If it is a multi-tap transformer, the wiring will be unique to the manufacturer but is very often indicated on a label or printed onto the former or case of the transformer. If it isn't a muti-tap transformer, no wires should be connected together, or you have worded the question very badly.

The neutral in single phase AC circuits is used as the common power return conductor for half phase operation. In a typical (US/Canada) 120/240 split phase system, generally used in residential applications, the voltage between neutral and either of the two hot conductors is 120 VAC, and the voltage between the two hot conductors is 240 VAC.

Neutral is also grounded at the distribution panel, as well as at the utility distribution transformer, in order to limit the voltage of any conductor relative to ground, and also to be able to detect ground faults by sensing imbalance between neutral and hot currents.

Note that this is not called two phase power. It is single phase, or split phase, and it comes from one center tapped transformer winding. The center tap is neutral.

output power/Rated power

More of an explanation is needed to give a good answer. It is possible for a line reactor to overheat due to harmonics. What voltage? What is the sub layout? When does this appear to occur? How old is the reactor (perhaps it is actually failing, so the harmonics are just pushing it over the edge)? How big is the reactor? Is there a capacitor bank nearby? Capacitance of the line? Length of the line? When is it switched on/off? How strong is the source bus that it is being switched to (is it turned on and the line is energized locally, or from the remote end)? etc., etc.

If possible, a better forum for such a question may be Eng-tips, although there are people here that may be able to give some good insights.

This nothing but forward and reverse recording... nothing but bidirectional meters

Here are several. We don't know which one would be the 'main' one.

Power =

(voltage) x (current)

(voltage)2 / (resistance)

(current)2 x (resistance)

(energy) / (time)

(voltage) x (current) x (power factor)

Ohm's Law answers your question. Voltage = Current x Resistance. In a series circuit you are in effect adding resistance. If the Voltage remains constant then the answer is obvious looking at the equation above.

1,175 watts. Which isn't very feasible

As it infers a voltage of 2350 Volts across the resistor.

Pls recheck you numbers and resubmit

As you don't specify how R1 & R2 are connected, it is impossible to give an answer to your question.

you are beautiful just your bald head just makes Aaron want to hug you.

By Aaron Albert

d. Dialtetric Strength

PHASE ADVANCER:phase advancers are used to improve the power factor of induction motors.The low power factor of an induction motor is due to the fact that its stator winding draws exciting current which lags behind the supply voltage by 90 degree.If the exciting ampere turns can be provided from some other A.C. source,then the stator winding will be relieved of exciting current and the power factor of the motor can be improved.This job is accomplished by the phase advancer which is simply an A.C exciter.The phase advancer is mounted on the shaft as the main motor and is connected in the rotor circuit of the motor. It provides exciting ampere turns to the rotor circuit at slip frequency.By providing more ampere turns than required,the induction motor can be made to operate on leading power factor like an over-excited synchronous motor.