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Why the neutral cable takes high current than the phase lines in three phase installation?
In a properly balanced three phase system, there is negligible current on neutral. If there is substantial current on neutral, then the system is not balanced and/or something is wrong.
Why cant take connection from phase line to neutral line?
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.
Does a three phase motor have a neutral?
No, three phase motors do not actually have neutral line unless you are referring to the motor control centre where a neutral line is required when your control coils and other components are single phase operated
What is dffrence between single phase and three phase?
In a single-phase system, one tension is provided by 1 phase and the neutral wire, which is convenient for domestic electricity consumption. As for the 3-phase system, you have 2 voltages: *between any phase and the neutral conductor, you have the PHASE VOLTAGE (V) *between one phase and any other, you get the LINE VOLTAGE (U) ;which is greater than V. Relation between these voltages is: U = V x sqrt[3] The advantage of such a "polyphased" system is obvious, since the electric power is divided into the three phase, you get less Joule loss compared to a single-phase system with the same total power. That's why great consumers of electricity (such as factories) chose to be powered through three-phase.
Why can the neutral wire diameter be reduced in relationship to the phase wires?
The Neutral wire should be the same gauge and size of the phase wires. Only the Earth or Equipment wire can be smaller than the phase(hot) wires. <<>> On a three phase four wire distribution system the neutral can be reduced in size. The neutral only carries the unbalanced load current and should be sized to that current. The highest current load to neutral of the three legs is used to calculate the neutral sizing. There is no reduced neutral allowed on discharge lighting and non linear loads. A demand factor of 70% shall be permitted to be applied to that portion of the unbalanced load in excess of 200 A.
What happens when phase to phase line is connected?
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 phase to phase, it is relative to the other phase. By Fourier Analysis, the difference between two phases of the same frequency, but of different phase angles, is still a sine (or cosine) wave. Also, by Kirchoff's Current Law, (implied, and I will (sort of) not repeat it here), current entering from one phase and equally leaving via another phase will not reflect at all in the neutral conductor.The simple answer is that connecting phase to phase is a short circuit, just like connecting phase to neutral.CommentThere is no such thing as 'phase to phase' or 'phase to neutral'. The correct terms are 'line to line' and 'line to neutral'.
Why 3 phase ac systems is preferred to 4 phase?
3 phase system has more power than a single phase system
What is a line to line voltage?
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.AnswerThere 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 is numerically equal to the phase voltage.In a three-phase, four-wire, system, the voltage between any line conductor and the neutral conductor is called a phase voltage. The line voltage is 1.732 times larger than the phase voltage.
Why is the neutral wire in any system half the magnitude of the line wire?
in case of motor, only 3core cable are used. Because there is phase balence between the winding. But in case of wiring,panel installation, 3.5c cables are normally used. Because there is unbalenced between the phase current. So the neutral taken to give the return path to flow of unbalenced (rush) current. Which always less than phase current,so the neutral cable is take half of the phase cable.
Why root 3 used in 3 phase system?
In a 3 phase, star connected system, the phase to phase voltage and phase to neutral voltage is calculated using root 3. That is, phase to phase voltage is root 3 times phase to neutral voltage. Also to calculate three phase power the voltage and current is multiplied by root 3 to obtain 3 phase power with unity power factor.AnswerIf you vectorially-add two quantities that are displaced from each other by 120 degrees, then the resulting quantity will be 1.732 (i.e. the square-root of 3) longer. Try it for yourself.So, for a wye (star) connected system, the phasor (vector) sum of two phase voltages will result in a line voltage that is 1.732 times larger than a phase voltage. For a balanced wye (star) connected load, the phasor sum of two phase voltages will result in a line current that is 1.732 larger than a phase current.
Why neutral wire current is more in 1-phase than the 3-phase?
On a typical house plug, there are three wires - the positive, neutral, and ground. Ideally, the positive and neutral wires carry the current (the neutral wire provides the return path for the current from the positive wire), and the ground wire carries no current. In a three phase system, you have three phase voltages of the same magnitude (ideally), but the three phase voltages are out of phase with each other by 120 degrees - meaning one is at 0 degrees, one is at 120 degrees, and one is at -120 degrees if you looked at them on an oscilloscope, and referenced to one phase. If you take (1 at an angle of 0 degrees) + (1 at an angle of 120 degrees) + (1 at an angle of -120 degrees), you will get zero. Thus the return path in three phase power is shared between the three phases, and the neutral wire in a 4 wire, three phase system is equivalent to the ground wire connected to your wall plug. The ground wire will only carry current when the "vector sum of the phase voltages does not equal zero" (meaning the simple equation at the beginning of this paragraph does not sum to zero - whatever it sums to is what is flowing in the neutral).
How do you wire a 110 V DB board from a 220 V 3 phase transformer supply?
In a wye system the voltage between any two wires will always give the same amount of voltage on a three phase system. However, the voltage between any one of the phase conductors (X1, X2, X3) and the neutral (X0) will be less than the power conductors. For example, if the voltage between the power conductors of any two phases of a three wire system is 220v, then the voltage from any phase conductor to ground will be 110v. This is due to the square root of three phase power. In a wye system, the voltage between any two power conductors will always be 1.732 (which is the square root of 3) times the voltage between the neutral and any one of the power phase conductors. The phase-to-ground voltage can be found by dividing the phase-to-phase voltage by 1.732 answer from ground and any phase
