What is earth, Neutral, Live wire?
Ground or earth in a mains (AC power) electrical wiring system is a conductor that provides a low-impedance path to the earth to prevent hazardous voltages from appearing on equipment (high voltage spikes).[citation needed] The terms ground and earth are used synonymously in this section; ground is more common in North American English, and earth is more common in British English. Under normal conditions, a grounding conductor does not carry current. Grounding is also an integral path for home wiring because it causes circuit breakers to trip more quickly (ie, GFI), which is safer. Adding new grounds requires a qualified electrician with knowledge particular to a power distribution region.
Neutral is a circuit conductor that normally completes the circuit back to the source. Neutral is usually connected to ground (earth) at the main electrical panel, street drop, or meter, and also at the final step-down transformer of the supply. That is for simple single panel installations; for multiple panels the situation is more complex. In a polyphase (usually three-phase) AC system, the neutral conductor is intended to have similar voltages to each of the other circuit conductors, but may carry very little current if the phases are balanced.
All neutral wires of the same earthed (grounded) electrical system should have the same electrical potential, because they are all connected through the system ground. Neutral conductors are usually insulated for the same voltage as the line conductors, with interesting exceptions.
A "live" wire is a wire that typically and intentionally has a voltage on it that can be detected with a voltmeter measured from the wire to ground. A "neutral" is not a "live" wire, however it does carry all return current on single phase and unbalanced three phase system. Touching the neutral in parallel will typically result in nothing happening, however if you somehow find yourself in series with the neutral it will be to your everlasting regret.
What is the difference between Live, Neutral, Ground wire?
A standard electrical system basically consists of live, neutral and ground. Electric current usually flows from live (also known as the HOT) to neutral (serves as return path for the current flow).
A lot of mains powered appliances needs these three wires to work safely but only two of the wires are used when the appliance works properly. These are the live (red) and the neutral (black) wires.
- The Live Wire:
This wire carries current to the appliance at a high voltage. In fact, it is the that carries the 220v AC used by most of our home appliances.
-Neutral wire:
It is the return path for an ac circuit which is supposes to carry current in normal condition. This current may be due to phase imbalance, 3rd or 5th harmonics that is the reason it is expected to carry current under normal condition. The neutral wire completes the circuit and carries current away from the appliance. This wire in essence carries or returns the 220v of the live wire back to the source. It is a wire with zero potential (volt).
Though it serves nothing in the conduction process, but only supports the live wire to maintain its potential through which mainly the current flows into our home.
-Earth wire:
The earth wire (green/yellow) is a safety wire and connects the metal case of the appliance to the earth.
Many a times, electrical and electronics devices/equipment due to physical exertion becomes short, they can even give shocks upon being touched. In such cases, earth wire which is present mostly in every devices and also in the main plug shunts the heavy current to the ground instead of surging through your body, thereby saving you the damage.
Earth wire is used for bypassing the current in case of emergency to the ground. A Ground represents an electrical path, normally designed to carry fault current when an insulation breakdown occurs within electrical equipment. Connections to the electrical path (Ground) are made convenient for the installation of electrical equipment. Some current will always flow through the ground path. This current will come from a number of normal sources.
Earth wire is normally thicker than live wire and it is usually tied to anything conductive surrounding wiring in order to prevent faults current from passing through the personnel or user of the device
This is the reason every main plug at home have got three insertions, one for live, another one for neutral, and the last one for the earth wire.
Ground is just a reference, think of it as the drain that sucks up all the electricity (as an extremely simplified view). Remember, earth ground is tied to a lot of the metal cases holding your wiring, and then tied to a pole thats several feet deep into the soil.
Also, before I round up, Neutral and Ground are connected together in the distribution panel and note that all neutral are ground but not all ground are neutral!!!
What are the functions of earth wire, neutral wire?
In domestic electrical connections, we have three different types of wiring: live or hot wire, neutral wire and earth wire. Each electrical circuit is composed of these wires, each of which is color coded. The live or hot wire is black in color, while the neutral is white and the earth wire is typically green in color. For an electrical appliance to work, the circuit must be complete. This simply means that the current should flow from a source, through the appliance and back to source. The live wire carries the current to the appliance, while the neutral wire carries it back. The earth wire is for our protection, in case the live wire makes a contact with metal casing of an appliance. When this happens, the current will pass to the earth instead of our body, thus saving us.
