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Current on neutral in a multi phase system is caused by imbalance between the phases.
Question: Are you talking about neutral or ground? The two are very different. Although neutral is grounded, it is expected to be a current carrying conductor, so current on neutral is normal, so to speak. Ground, on the other hand is a protective circuit that is not supposed to have any current on it at all.
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What is the formula to get neutral current in three phase transformer where three phase cureent are given?
Neutral current is the vector sum of the phase currents. You should be able to add up the phase currents from their polar quantities.
How three phase line current convert in single phase?
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.
How much current will flow in neutral line for three phase supply 100amps?
If all three legs of the system are balanced then zero amps will flow all the way up to 100 amps if only one leg of the three phase system is used. The neutral in a wye three phase system carries only the unbalanced current. This is why in services for a three phase four wire system you are allowed to reduce the size of the neutral conductor.
What if the fourth wire in a three phase is having impedance would the current in the neutral line remain to have a value of zero?
When the system is in balance, with three equal phase currents, there is no current in the neutral 4th wire and it is not needed. However if the load is unbalanced, the neutral is needed to maintain the star point at zero volts.So for example a street of houses fed by a 3-phase supply needs a neutral because the houses draw unequal currents from the different phase lines, although a large enough collection of houses would tend to balance itself out.If a three-pase system has equal currents the current in the neutral is zero. If two phases draw equal current but the third has no load, there is an equal current in the neutral, and if one phase draws current but the other two have no load, there is again an equal current in the neutral.ANOTHER ANSWERA three-phase, four-wire, system comprises three line conductors and a neutral conductor. If the load supplied by this system is balanced (i.e. the loads connected between each line and neutral are identical in all respects), then no current will flow in the neutral conductor regardless of its impedance. If the load is unbalanced, then a neutral current will flow in the neutral conductor. In other words, the impedance of the neutral conductor plays no part in whether or not there is a neutral current.
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.
Why neutral cross section is half the phase in three phase cable while it has to carry current of summation of all phase..?
The current carried by the neutral of a three phase four wire system is the un balanced current. If the three phase system was completely balanced on all three phases there would be no need for a neutral, eg a three phase motor. This neutral current will be less that the phase current so a reduction in the neutral size is allowed.
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.
What is the limit or range of the neutral current in an unbalanced three phase system for it to be regarded as faulty?
The limit or range of the neutral current in an unbalanced three phase system is the third harmonic in single phase non-linear load current is the major contributor to neutral current.
What is the formula to get neutral current in three phase transformer where three phase cureent are given?
Neutral current is the vector sum of the phase currents. You should be able to add up the phase currents from their polar quantities.
How do you reduce neutral to earth voltage in three phase system?
It is done by connecting the neutral to earth at the transformer that produces the three-phase supply. If the three phase wire supply equal currents, there is no current in the neutral wire and its whole length stays at earth potential, but if there is current in the neutral it produces a small voltage on the neutral at places away from the transformer.
Why set an overload relay to full load current divide by root three in a star delta starter?
In a Wye/star system the overloads look at the phase to neutral/ground current; not phase to phase current. Which is always calculated as root three or 1.73205.............etc. Therefore the overloads have to be set to the phase to neutral/ground current.
Why is the neutral wire thinner in overhead 3-phase AC transmission line?
A smaller neutral wire in a three phase system can be used because it does not carry the full line current. It carries the unbalanced current of all three leg loads. This is one reason that three phase loads on a distribution panel should be equalized as much as possible to reduce the current on the neutral.
How three phase line current convert in single phase?
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.
What is line phase neutral?
Line, phase, neutral are terms used to describe the conductors in a three-phase system. The three live wires are called 'lines', and less correctly, 'phases'. Neutral is used for the fourth wire which in a balanced system carries no current.
How much current will flow in neutral line for three phase supply 100amps?
If all three legs of the system are balanced then zero amps will flow all the way up to 100 amps if only one leg of the three phase system is used. The neutral in a wye three phase system carries only the unbalanced current. This is why in services for a three phase four wire system you are allowed to reduce the size of the neutral conductor.
What if the fourth wire in a three phase is having impedance would the current in the neutral line remain to have a value of zero?
When the system is in balance, with three equal phase currents, there is no current in the neutral 4th wire and it is not needed. However if the load is unbalanced, the neutral is needed to maintain the star point at zero volts.So for example a street of houses fed by a 3-phase supply needs a neutral because the houses draw unequal currents from the different phase lines, although a large enough collection of houses would tend to balance itself out.If a three-pase system has equal currents the current in the neutral is zero. If two phases draw equal current but the third has no load, there is an equal current in the neutral, and if one phase draws current but the other two have no load, there is again an equal current in the neutral.ANOTHER ANSWERA three-phase, four-wire, system comprises three line conductors and a neutral conductor. If the load supplied by this system is balanced (i.e. the loads connected between each line and neutral are identical in all respects), then no current will flow in the neutral conductor regardless of its impedance. If the load is unbalanced, then a neutral current will flow in the neutral conductor. In other words, the impedance of the neutral conductor plays no part in whether or not there is a neutral current.
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.
