What is the relationship between the line and phase current?
IT depends upon the 3-phase connnection ..if it is
Y connection:line current = phase current
if it is delta connection: IL=(root 3)IPh
What is the relationship between line current and phase current in a three phase star connected system?
The line current is exactly equal to the corresponding phase current, in a star-connected system, because it is the same current.
'Line currents' are those currents flowing in the line conductors, whereas 'phase currents' are those currents flowing in the phases. Each line current is the phasor sum of the phase currents at the junction between a line and two phases. For a balanced load, the line current is 1.732 times the phase current.
A 'phase current' is the name given to the current in a phase and a 'line current' is the name given to the current in a line. 'Lines' are the conductors that connect a three-phase load to a three-phase supply. 'Phases' are the individual windings in a machine, or the individual impedances that make up a three-phase load. In the case of a star (wye) connected load, the line current is numerically equal to the… Read More
Because if you apply Kirchhoff's Current Law to the junction between the line current and the two phase currents, the line current is the phasor (vector) sum of two phase currents. For a balanced load (only), this works out to 1.732 x phase current.
A load current is a current drawn by an electrical load. In other words, it is the current flowing from the source to the load. For a single-phase system, a line current is a current flowing through the line, or 'hot', conductor, while the current through the neutral conductor is called the neutral current. For a three-phase system, the three 'hot' conductors between the load and the source are called 'lines' and, so, the currents… Read More
A phase current is the current passing through a phase, whereas a line current is the current flowing through a line.
In a delta connection, the line voltage is equal to the phase voltage. In a star connection, the line voltage is 1.732 larger than the phase voltage.
On a delta system the line current would be 1.732 times higher than the phase current. In a Wye system the line current and phase current are the same. In a parallel circuit (Delta) current divides. In a series circuit (Wye) current stays the same. Another Answer Line currents pass through line conductors, whereas phase currents pass through phases. 'Phases' are (in the case of a supply) are the windings of a three-phase alternator or… Read More
in three phase you have lost more Answer For a given (balanced) load, the line current in a three-phase system is lower than for a single-phase system by a factor of 1.732 and, since line losses are proportional to the square of the line current, three-phase systems have lower line losses than a corresponding single-phase system.
Phase voltage is sqrt(3) times the line voltage, that is 1.732 times. So for a 240 v line voltage the phase voltage is 416 v.
Sqrt(3). Line current is 1.73 times phase current. Answer Line currents occur in the three lines (the conductors that connect the supply to the load). Phase currents occur in the phases (i.e. in the three individual loads, or in the three armature windings of the supply generator). For a balanced wye-connected load, the line currents are numerically-equal to the phase currents. For a balanced delta-connected load, the line currents are 1.732 times the phase currents.
What is the current difference in a 3 phase motor running continuously in star connection and delta connections?
The voltage difference between star and delta is 1.732, the square root of 3, or, going from delta to star, 1 over 1.732, which is 0.5774. That is the same as the current difference, neglecting motor efficiency at the two different operating voltages. The power difference between star and delta is 1.7322, or 3, and between delta and star is 0.57742, or 0.3333. <<>> In a wye connection, the line current is equal to the… Read More
Balanced Star (Wye) Connected Systems: Line Voltage = 1.732 x Phase Voltage Line Current = Phase Current Balanced Delta Connected Systems: Line Voltage = Phase Voltage Line Current = 1.732 x Phase Current
1.732 is the square-root of three (and is often written that way in the relevant equations), and the relationship between a three-phase, four-wire, system's phase and line voltages. That is, the line voltage is 1.732 times greater than the phase voltage, and the line current is 1.732 times A three-phase, four-wire, system is provided by, for example, a transformer, whose secondary windings are connected in a consideration called 'star' or 'wye'. This configuration provides four… Read More
If there is a voltage differential from phase to phase, and a conductance (inverse of resistance) between them, then current (amperes) flows. This is no different than phase to neutral, i.e. voltage across conductance generates current, (I = EC, or I = E/A) except that neutral current is zero in a true phase to phase connection. Note that phase angle is always relative. In phase to neutral, it is relative to (typically) neutral; while in… Read More
The current is the same in the three live wires. The voltage can be described as the line voltage (phase to neutral) or the phase voltage (phase to phase) which is larger by a factor of sqrt(3). So a line voltage of 230 v corresponds to a phase voltage of 400 v.
In a three-phase system, a line voltage is the voltage measured between any pair of line conductors. The line current is the current flowing in any of the lines. Line voltages are usually numerically equal when measured between any pair of lines. Each line current, however, may be different if the load is unbalanced, or the same if the load is balanced. In a residence, the line voltage is the voltage between the incoming line… Read More
the difference between the two line currents - anything from zero (no neutral current ) if perfectly balanced or only line-to line loads up to the entire line current if completely unbalanced (all current on one line and neutral, no current in other line).
The RC circuit can reduce the phase shift between the voltage and current in the power line. The phase shift is caused by the inductance of the motor. The phase shift between the voltage and current in the power line causes problems due to the presence of so called imaginary current or power that does no work but must be supplied by the power source.
What is the relationship between phase and line values of current and voltage quantities for star and delta connected systems?
A: A DELTA transformer is a 1:1 voltage transfer delta to Y IS 1:2 voltage transfer. That is for 3 phase system, If the phases are not exactly matched or the voltage is not exactly right then on a Y setup there will be circulating current at the common node.
A connection can be taken between phase lines, or between one phase and neutral. Both methods give a single-phase supply. Between phases the voltage is sqrt(3) times more than between one phase and neutral. In each case the load gives an unbalanced current on the 3-phase system but the idea is to average out the unbalances over a group of single-phase loads.
The phase voltages (i.e. line-to-neutral in a 4-wire system, or line-to-line in a 3-wire system) of a three-phase system are displaced from each other by 120 electrical degrees. Each phase voltage, in fact, is rarely in phase with its phase current, as the phase-angle (the angle by which a phase current lags or leads its phase voltage) is determined by the load not by the supply. In general, most loads are resistive-inductive so the phase… Read More
Answer for USA, Canada and countries running a 60 Hz power supply service. Most power lines will carry 3 phase power. Basically there is 240V (or whatever voltage your country uses) between each phase and ground, so between phase 1 and ground, there will be 240V or 120V, between phase 2 and phase 3 will be 480V or 208V. <<>> Answer for countries in Europe and other world areas running a 50 Hz power supply… Read More
If you are referring to an alternating current system, then a phase describes a winding, or a load, that is connected between any two line conductors in a delta-connected system, or between any line and the neutral conductor in a wye-connected system.
in safe systems the summation of every phase currents is equale to the line current,but in deffect system not equale , this difrance circulates between parallel phases
In a balanced 3-phase system, if the three loads are star connected, the line current is equal to the load current. If the loads are delta connected, the line current is less than the load current by a factor of 1/sqrt(3).
given a balance three phase, three wires system with star-connected load for which lime voltage is 230v and the impedance of each phase is (6+j8)ohm. find the line current and power absorbed by each phase.
They are identical.
The terms 'phase voltages' and 'phase currents' are used in three-phase alternating-current systems, to distinguish them between 'line voltages' and 'line currents'. In a three-phase system, the generator has three coils which generate voltages that are displaced from each other by 120 electrical degrees. The generator is then connected to the load using three conductors, called line conductors. The generator's three coils are described as 'phases', and the generated voltages are called 'phase voltages', while… Read More
Line current = 1.732 x Phase Current Comment Only for balanced loads.
A phase current is the current passing through a phase, whereas a line current is the current flowing through a line. In the case of a balanced delta-connected load, IL = 1.732 IP. In the case of a balanced star-connected load, IL = IP. For unbalanced loads, these relationships don't hold true, and must be individually calculated.
normally delta connection wired in 3 phase induction motor. during starting wiring is in Star and after running normal speed changeover to delta .beacause starting time its phase voltage equals less root3 times of line voltage ,line current and phase current equals. in Delta phase voltage and line voltage equals, and phase current equals root3 times line current
In a 3 phase system, the voltage measured between any two phase is called line to line voltage. And the voltage measured between line to neutral is called phase to neutral (line to neutral) voltage. Answer There is no such thing as a 'phase-to-phase' or a 'phase-to-neutral' voltage. The correct terms are 'line-to-line' and 'line-to-neutral'. The voltage between any two line conductors is called a line voltage. In a three-phase, three-wire, system, the line voltage… Read More
Write dowen the relationshipbetween line and phase the 3phase system if voltageline and currentline are line value voltage power and current power are phase value?
A-for star connection E(line)=1.73E(Phase) I(line)=I(Phase) & B-for delta connection E(line)=E(Phase) I(line)=1.73I(Phase)
In the case of a delta connection, measuring phase current is relatively difficult, as access to the phases of most loads (e.g. motors) for the purpose of inserting an ammeter is not very practical. In the case of a star (wye) connected system, of course, it is relatively easy because the phase current is exactly the same as the line current. And line currents can be read very easily because the line conductors are accessible… Read More
Negative sequence current is defined as 3I2 = (phase 1)*(1angle 0) + (phase 2)*(1angle 240) + (phase 3)*(1angle 120) Negative sequence current is seen in three phase power systems due to natural system imbalance. Also during unbalanced fault conditions such as line to line, Line to ground, and line to line to ground faults. It is not seen in purely balanced three phase faults.
For a transformer, the turns ratio always applies between its primary and secondary windings. So the turns ratio for a three-phase transformer is the ratio of primary to secondary phase voltages, not between line voltages.
KVA means product of voltage and current. For 3 phase generator, its KVA = (1.732 X (Line Voltage) X Current)/1000. Put line voltage in this equation and get current.
To get KW, multiply KVA by the power factor (cosine of the phase angle between voltage and current on the line).
There is no such thing as a 'phase-to-phase' voltage. The correct term is 'line-to-line' voltage or 'line voltage'. For a star (wye) connected system, the line voltage is 1.732 times the phase voltage, where the phase voltage is measured between any line and neutral.
For a three-phase, three-wire, system, the line voltage and the phase voltage are numerically equal to each other, and both are measured between any pair of line conductors. For a three-phase, four-wire, system, the line voltage is 1.732 times the phase voltage. The line voltage is measured between any pair of line conductors, whereas the phase voltage is measured between any line conductor and the neutral conductor.
If two phases are shorted together, you will get a phase to phase fault, which will cause protective devices to operate (fuses, relays, breakers, etc.). Comment There is no such thing as a 'phase-to-phase' voltage, although the term is frequently, but misguidedly, used in the field. The correct term is 'line-to-line' voltage, because phases exist between lines.
Would only one wattmeter be needed to measure the total three-phase power on a balanced three-phase four-wire system?
Yes. The wattmeter's current coil will have to be connected into one of the line conductors, and its voltage coil between that same line conductor and the neutral point of the load. Connected this way, the wattmeter's voltage coil is measuring one of the three phase voltages (line-to-neutral voltage) while its current coil is measuring the corresponding phase current (for a 4-wire system, the phase current = line current). The power factor (cosine of the… Read More
The neutral wire is used to close the current circuit between the load and the supply distribution's neutral bar. Where as the feeder line is used to supply the current between the supply distribution and the load.
First of all: 'line' and 'phase'. The conductors that connect a three-phase load to a three-phase supply are called 'line conductors' or, simply, 'lines'. The individual three-phase loads are 'phases'. So voltages measured between line conductors are called 'line voltages' whereas voltages measured across phases (individual loads) are called 'phase voltages'. THERE IS SIMPLY NO SUCH THING AS A 'PHASE-TO-PHASE' VOLTAGES. Similarly, currents passing along line conductors are called 'line currents', whereas currents passing through… Read More
Impossible. 25KVA is a power measurement. To convert to amps, you must have voltage. In the case of three phase: P = Voltage * current * sqrt(3) (assuming voltage is line to line) The current in the equation is phase current, thus the current calculated above will flow in all three branches, and will be 120 degrees out of phase with the other phases.
There is no such thing as 3 phase to a DC motor. DC is direct current and is totally different from AC. 3 phase only exists in AC or Alternating Current
phase - hot neutral - return ground, earth - safety ground Comment The correct term is 'line', not 'phase'. For example, after incorrectly using the term, 'phase', for many years, the latest edition of IET Wiring Regulations (BS7671) now uses the correct term, 'line', to describe the energised ('hot') conductor. Despite this, the terms are widely misused in the field. Unless used in this way, the resulting terms, 'line voltage (and current)' and 'phase voltage… Read More
Yes, if the power factor (cosine of the phase-angle between voltage and current) is ' 1 '. In order for that to be true, the total load impedances on the line have to be pure resistive, with zero reactance. All of this stuff applies only on an AC line. On a DC line, voltage and current are always in phase, the power factor is 1, and KVA = KW .
In a three phase four wire system - voltage between any one phase and the neutral is single phase. Hence the single phase equipment or load between any one phase and the neutral. Another Answer A single-phase load can be connected either between any line conductor and the neutral conductor, or between any pair of line conductors. The choice is dependent on the voltage rating of the load, which must match either the phase voltage… Read More