What is Neutral?
In a 3 Phase supply system, its star point is called Star Point or Neutral Point by making Star Connection. And the wire coming out of that point is called Neutral wire which is always represented by black wire.
- Ohm’s Law | Who was Omh? | 3 important formulas of Ohm
- What is a Polyphase System?
- What is Neutral In Electrical? | Purpose of Neutral Wire in electrical Circuit
- What is 3 Phase Induction Motor?| Types, structure and working principle of Three phase induction motor.
What is the Purpose of the Neutral in Electrical?
Star connection and delta connection are done in the 3 Phase supply system. Wires supplied from their points are supplied to the load.
In both these connections, the additon of current flowing through all three phases is zero ‘0’. (IU + IV + IW = 0)
Because at any moment in the formation of 3 phase, the highest value is at one stage, the same phase is at the highest value. And the third failure is around zero or zero.
Therefore, the vector sum of current or voltage of all three phases is ‘0’. This means that, if two phases are carrying current, then the third phase is carrying current. That means the path to the return of the third phase current is complete.
As we know, Neutral is not available in delta connection. Therefore, one of the three phases performs the task of completing the return path of current in delta connection. Neutral wire in Star Connection completes the return path of current.
The current flowing through the Neutral is equal to the addition of current flowing through all the three phases.
IU + IV + I W + IN = 0
IU + IV + I W = IN
Why is the size of a Neutral Conductor Smaller than Other conductors
If the load connected at 3 Phase is balanced then the current flowing through the Neutral is zero (0). But if the load is unbalanced, then the current flow is different from the three phases. And at that time there is also a current flow from the Neutral.
At unbalanced load, the current flowing through the Neutral is lower than the current flowing through the other phase. Because of this the size of a Neutral conductor smaller than other conductors
How is Artificial Neutral prepared?
Neutral wire is the conductor that completes the return path of current. But Neutral is not available in delta connection. And where we have to connect only the equipment working on single phase and there is only 3 Phase Supply available, then that device cannot be connected to the 3 Phase Supply.
Neutral can be made at that place by artificial method. And single phase equipment can be connected.
3 resistances of the same weightage are taken. (Example three bulbs of 100 W / 200 W)
The star connection is made as shown in the figure. An artificial Neutral is formed at the star point of that star connection.
What is Neutral Earthing?
In the 3 Phase Supply System, making a star connection to that star point through the conductor, meaning it to a suitable depth in the ground, and from there the Neutral wire exit is called Neutral earthing.
Why is Neutral Important to Earthing? | Why is Neutral connected to Earth?
What happens if Neutral is not grounded?
In the 3 Phase 4 Wire System, it is very important to Earth the Neutral. Because in AC Distribution system, 3 Phase 4 Wire System has single phase and one Neutral wire connected with single phase load.
And 3 phase load is connected at 3 phase. When such loads are added, the load should be split in even proof at all three phases. But this does not actually happen. The load of all three phases can be unbalanced.
When there is an unbalanced load, the current flows from the Neutral (Neutral). In this situation, if Neutral is not given meaning, then it comes to the Unbalanced Current Star Point. From there, the phase winding whose impedance is less, the current starts to flow to that side.
Due to this, the current of that phase increases and the system starts unbalance again. The voltage found in one phase and Neutral is very low and the voltage found in other phase and Neutral starts getting very high.
if Neutral is not grounded thenVoltage may become unstable by receiving a high voltage from all three phases. Because of this, alternators or transformers may be overloaded. If this is not the case, then it is very important to give meaning to Neutral.
What happens when Neutral is connected to Earth?
The meaning of Neutral means that the current flowing from the Neutral at Unbalanced Load moves directly into the ground through the Earth conductor while not going towards other phase windings.
Because of phase winding and earthing, the resistance of earthing is very less. And the current always flows towards the lower resistance. And thus by Neutralizing the Neutral in electrical 3 Phase System, the voltage and stability of the machine and equipment are safe.