Friends, whenever we talk about single phase, we take one phase and one neutral wire, but in three-phase, we take three phase wire. We do not take neutral wire in three phase. Some people are always confused about the working of the neutral wire.
So friends, neutral wire gives return path to phase current. Mean with the help of neutral wire phase current can return to generator or ground. As you can see in the below photo, the first supply comes from source and then goes to load.
Then supply is returned to the generator through neutral wire.
Friends, now the question will come to your mind why do we use neutral wire? What will happen if we do not use neutral wire? Along with this, some people will say that in a three-phase system, there are only three-phase wires, and there is no neutral wire.
Friends, we will discuss all these questions in today’s post, so let’s first talk about why we use neutral wire? Then we will know why there is no neutral wire in the three-phase.
Why Neutral wire used?
Friends, as we discussed above, the neutral wire is used to giving the return path to the phase current. This means current which comes from the generator, neutral wire sends this current again in generator or earth.
Now the question comes, what happens if the neutral wire is removed? So, friends, do you know that current flows in a closed path? Close path means the loop where the network starts and ends at the same point. It is called a closed path.
As you can see in the photo below, our network starts from the cell and ends again on the cell after traveling from the switch, bulb.
If our path becomes open from somewhere, that is, due to some fault in the circuit or any other reason, it is called an open path. As you can see in the photo below that the wire broke in the middle, due to which our circuit started from the cell but ended in the middle. This is called an open path.
Now, friends come back to our main question why do we use neutral wire? As we have just understood, current always flows in a closed path. This means one wire is used to carry the current from the generator to load and the neutral wire is used to return the current.
Now, if we do not use the neutral wire, then there is no close path. Because we have only one wire to carry the current, we don’t have any wire to return the current. So our path will not be closed, and no current will flow.
You can say that the neutral wire is used to provide a closed path in our electrical system so that current can flow.
Now friends, you will ask why there is no neutral wire in the three-phase, do we no need for close path in that?
Why there is no neutral wire in Three Phase?
Friends, many people think that there is no neutral wire in three-phase, but friends it is not true. Always closed path need for current flow. But you also have to keep in mind that it is not necessary that we need a separate wire for close path.
As in three phase we have three phase wire. You can see their wave form below.
We can see in this wave form that when our R phase brings current from generator to motor or any other device, then at that time the direction of current in both the other phases Y and B reverses.
This means that when our R phase brings current to the equipment, at that time our Y and B phases work to provide the return path to that current. That is, Y and B act as neutral wire.
In this way we get a closed path and current starts flowing.
Friends, if we see the summary of the whole post, then firstly the neutral wire provides the return path to the current coming from the generator. That is, it sends the current back from the device to the source. The second question was what will happen if we do not put the neutral wire?
The answer is there will no closed path in our system due to which current will not flow. Next and last question why there is no neutral wire in the three phase?
In three phase system we have three wires, when the current from one wire goes to the equipment, then both the other phases provide the return path to the current, which means one wire acts as phase and other two wires work as neutral wire.
We hope friends that you got all the question that why neutral wire is used, why there is no neutral wire in three phase system? If any question left then you can comment out below or you can send question to us on Instagram “Electrical Dost.”
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