Neutral and Earth

The role of Neutral is to close the circuit and carry the consumer load current back to the transformer point while the earth shall carry no current in normal situations.

Different systems are used to minimize the voltage difference between neutral and local earth ground. In some systems, the neutral and earth join together at the service intake (TN-C-S); in others, they run completely separately back to the transformer neutral terminal (TN-S), and in others they are kept completely separate with the house earth having its own rod and the neutral connected to earth within the distribution network (TT). In a few cases, they are combined in house wiring (TN-C), but the dangers of broken neutrals and the cost of the special cables needed to mitigate this mean that it is rarely done nowadays.

Please go through following links

http://professional-electrician.com/technical/%E2%80%98neutral-earth%E2%80%99-faults

http://www.ab.com/support/abdrives/documentation/techpapers/rfignds.htm

Er.digu

Dear All,

If we can use Earth wire as Neutral wire. Then what is the Different between them?Why we use neutral wire instead of earth?

The role of Neutral point (Neutral wire) is to close the circuit and carry the consumer load current (return current) back to the transformer point) while the earth point (earth wire at consumer premises) shall carry no current in normal situations. The earth point (earth wire) is used to bond the metallic chassis of consumer equipment that is isolated from live wires. Hence, the earth wire is used to ensure safety of equipment and personnel in two cases:
-The earth wire will carry (short) currents in case of chassis of the equipment becomes electrified , i.e. a bare live conductor touches the metallic chassis. This short current will trip some circuit breaker in the way immediately.
- The earth wire will carry (Leakage) small currents due to insulation deterioration, humidity and carbon deposit on the insulator. In this case a special breaker called ELCB (Earth Leakage Circuit Breaker) or RCCB (Residual Current Circuit Breaker) that is calibrated to trip at small currents (of the order of 6-30 mA for residual purposes and 300mA for industrial purposes). Not all electric codes enforces the uses of ELCB's or RCCB's.
Hope you found this answer of value.

Er.digu

Dear All,

If we can use Earth wire as Neutral wire. Then what is the Different between them?Why we use neutral wire instead of earth?

1) Neutral define as a closed path of electical ckt having zero potential.and earth wire is a protection path of electical ckt.
2) Neutral is a return path to complete the electrical circuit. It is originated from transformer star point.Earthing is connected to the panel or equipment to protect the equipment & human life when leakage occurs.
3)An Earth wire is used to provide a path for leakage current in case the body of an equipment is in touch with a naked portion of live wire whereas a neutral wire is there to provide a closed loop to the flow of current in an equipment. The neutral is earthed at the Distribution transformer secondary side.
4) neutral wire is there to form closed path of current earth wire is there for the protection of equipment from the leakage current and also provide ground path to leakage currentand hence saves human life  

Chetan2490

Er.digu

Dear All,

If we can use Earth wire as Neutral wire. Then what is the Different between them?Why we use neutral wire instead of earth?

Hello Jeet,

Earth point is the point connected locally to ground, i.e. earthed locally at the consumer premises while Neutral point is a point that is connected to ground (earthed) as well but faraway at some point of the power company equipment (e.g. the star point of the secondary stepdown transformer feeding the consumer premises). See the picture that I prepared to illustrate the answer. Hence neutral at consumer premises is ground point at some other company's equipment.

The role of Neutral point (Neutral wire) is to close the circuit and carry the consumer load current (return current) back to the transformer point) while the earth point (earth wire at consumer premises) shall carry no current in normal situations. The earth point (earth wire) is used to bond the metallic chassis of consumer equipment that is isolated from live wires. Hence, the earth wire is used to ensure safety of equipment and personnel in two cases:
-The earth wire will carry (short) currents in case of chassis of the equipment becomes electrified , i.e. a bare live conductor touches the metallic chassis. This short current will trip some circuit breaker in the way immediately.
- The earth wire will carry (Leakage) small currents due to insulation deterioration, humidity and carbon deposit on the insulator. In this case a special breaker called ELCB (Earth Leakage Circuit Breaker) or RCCB (Residual Current Circuit Breaker) that is calibrated to trip at small currents (of the order of 6-30 mA for residual purposes and 300mA for industrial purposes). Not all electric codes enforces the uses of ELCB's or RCCB's.
Hope you found this answer of value.

KIRAN_DABHI

No you can not use earth wire as neutral for safity.because If the neutral wire was somehow broken or interrupted,
YOU would be electricity's shortest path back to the earth, so the ground wire is like an insurance policy to carry
the current back so you don't get shocked in case the neutral wire fails.


from this example you can easily understand difference between them,

If the live wire inside an electric device comes loose and touches the metal casing, you will get an electric shock.
The earth terminal is connected to the metal casing, so the current goes through the earth wire instead of through you.
The earth wire route has a very low resistance, so a big current flows which blows the fuse, disconnecting the device.



now Some devices such as vacuum cleaners and electric drills don't use an earth wire. You can't get a shock off the casing
even if the wires inside become loose. This is because the casing is made of plastic, or because the wire can't touch
the casing.For that devices you usally found only phase and neutral socket.



REGARDS,
KIRAN P DABHI