answersLogoWhite

0


Best Answer

When you put negitive to positive

User Avatar

Wiki User

11y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: When does a neutral current flow?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Continue Learning about Electrical Engineering

Why there is zero volt across neutral earth of isolation transformer?

Geez, because it is just that; A NEUTRAL EARTH, there should be equal potential on each side, therefore no current flow, and no voltage.


Why neutral wire carry no current?

Usually yes, sometimes no. For instance: The neutral in a single-phase, 120V (in the US) branch circuit, such as one feeding receptacles, does. The neutral in a 120/240V circuit feeding a 240V appliance does not. The neutral in a 480Y feeder feeding a balanced load does not. A neutral is there because of the possibility that current flow could occur. For instance, in a US household, with 120/240V service, if you plugged in 5 100 watt lamps on one side of the line, and another 5 100 watt lamps on the other hot leg, there would be no neutral current in the service cable feeding the house. The loads are said to be 'balanced'. The 500 watts of power flowing into the first hot leg goes through the first set of lamps, then the second set, then out the other hot wire. Neutral current still flows in the individual branch circuits, of course. Now, if you moved one of the lamps to the other side, 600 watts would be coming into that side, but only 400 would be going back out the other hot wire, so 200 watts would flow through the neutral.


How 3 phase unbalanced current flow through neutral?

Kirchoff's Current Law states that the signed sum of the currents entering a node is zero. If the neutral point is the node, then, in a balanced system, hot matches the other two hots, resulting in no current through neutral. Any imbalance, either due to neutral to hot current flow that is not balanced by the other two neutral to hot current flows, or due to ground fault, will result in a current flow on neutral, so that the sum of zero is maintained.When you think about this, remember that the law said "signed" and "entering". When you analyze a circuit, simply be consistent in your usage. For instance, in a balanced system, current entering the neutral node from one hot side is considered positive, and the current entering the neutral node from the other hot side is considered negative, i.e. it is leaving, not entering.This gets more complicated in three phase power, because now you have to consider phase angle, but the concept is exactly the same...If you are connected in wye, with a neutral, then the neutral conductor will have zero current on it only if the three phase hots have the same current on each. If you do vector analysis on this, adding up sin(x), sin(x+120), and sin(x+240), you get zero.The same thing happens when you are delta connected, without a neutral, but then the imbalance occurs out in the distribution system, beyond the service transformers, because the distribution system is generally a wye system.Ground fault will, of course, "change the rules", because you no longer have only four paths to that neutral point node. In fact, that is how ground fault current interrupters (GFCI's) work - they measure outbound current and compare it to inbound current - they must be equal and opposite, i.e. they cancel each other out - otherwise there is another path - a ground fault - and the device trips.


Voltage is pressure and current is flow what opposes flow?

Reverse current.


What is a flow of electricity?

a current

Related questions

What will happen without a neutral wire?

Current needs a return path to earth to flow. The neutral carries this flow. Therefore, no neutral and no current flow.


When the neutral switch is open where do the line current flow to?

There is never a switch installed in a neutral line.


When phase and neutral are glowing what is the problem in circuit?

There is more current flowing and the wire can not flow that much current.


Is there any current flow through the neutral wire of single phase motor?

Yes. It is identical to the line current.


Can ground conductor use as a neutral conductor in a house wiring?

No. Absolutely not. The ground conductor is not rated to carry constant current flow. It is only rate to carry fault current flow.


What would cause 5 volts to be sensed at water supply pipe?

The water pipe is not properly grounded AND there is a ground fault or neutral imbalance in the house. Alternatively, there could be a neutral problem. In an ideally balanced house, the current on one hot leg balances the current on the other. This means that there is no current on neutral. In practice, there is some imbalance, and that common mode current does flow on neutral. If a circuit has a ground fault, the current return for that circuit is on ground, instead of neutral. That is wrong, and must be corrected. However - neutral and ground ARE connected together at the distribution panel. They are also connected at the street, so imbalance current could flow through ground instead of neutral. How much voltage is dependent on how much impedance. If there is a voltage at the house ground, and no ground fault or major imbalance, it calls into question the adequacy of the ground path, however, it is also possible that neutral is open, causing the imbalance current to flow through ground alone.


What is the reason for using a neutral current transformer on a transformer?

A current transformer is primarily used at the neutral point of a transformer for earth fault protection. A neutral current transformer will measure any ground fault current which will essentially flow from the star point of the transformer. A fault-detection device other devices is connected to the current transformer and, if the fault current exceeds a certain trigger value, the fault-detection device will give a trip command to an earth-fault relay to disconnect the supply of electricity to the transformer.


Why zero sequence current cannot flow through a star connected machine unless the neutral is grounded?

If the neutral point is not earthed than the zero sequence current will not have any return path.It will be an open circuit for the zero sequence circuit.


Why there is zero volt across neutral earth of isolation transformer?

Geez, because it is just that; A NEUTRAL EARTH, there should be equal potential on each side, therefore no current flow, and no voltage.


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.


What is difference between ground and neutral?

A neutral is an active conductor in the circuit. It is grounded at the source but that's for another discussion. The ground exists to ensure the proper operation of over current devices like fuses and breakers in the event of a fault.


What is use of neutral in a wall receptacle?

The neutral in a receptacle is the return conductor to complete the circuit back to the distribution panel. When a device is plugged into the receptacle this completes the circuit and allows the current to flow and the device to operate.