Earthing and types of Wires and Cables

Earthing is defined as “the process in which the instantaneous discharge of the electrical energy takes place by transferring charges directly to the earth through low resistance wire.” Low resistance earthing wire is chosen to provide the least resistance path for leakage of fault current.

In simple words The process of sharing the charges with the earth is called earthing. Mostly, the galvanized iron is used for the earthing. The earthing provides the simple path to the leakage current. The short-circuit current of the equipment passes to the earth which has zero potential. Thus, protects the system and equipment from damage.

In homes, there shall be three types of wires, live, neutral, and earth. Live and neutral carry electric current from the power station and the earth is connected to the buried metal plate. Electric appliances like refrigerators, iron boxes, and TV are connected to the earth wire while operating. Hence, these devices are protected from the surge or faulty electrical supply. Local earthing is done near the electrical meter of the house.

There are three types of earthing, they are:

• Pipe earthing
• Plate earthing
• Strip earthing

*Pipe earthing is the best and most efficient way of earthing and is also easily affordable. Pipe earthing uses 38mm diameter and 2 meters length pipe vertically embedded in the ground to work as earth electrodes.

*In plate earthing, an earthing plate made of copper or G.I. is buried into the ground at a depth more than 3 meters from the ground level. This earthing plate is embedded in an alternative layer of coke and salts.

*Strip earthing is used in transmission processes. Strip electrodes of cross section not less than 25mm x 1.6mm of copper or 25 mm x 4mm of G.I. or steel are buried in horizontal trenches of a minimum depth of 0.5m.

Advantages of Earthing

1. Earthing is the safe and the best method of offering safety. We know that the earth’s potential is zero and is treated as Neutral. Since low equipment is connected to earth using low resistance wire, balancing is achieved.
2. Metal can be used in electrical installations without looking for its conductivity, proper earthing ensures that metal does not transfer current.
3. A sudden surge in voltage or overload does not harm the device and person if proper earthing measures are done.
4. It prevents the risk of fire hazards that could otherwise be caused by the current leakage.

Types of wires

There are 6 types of wires-

* Vulcanized Indian Rubber wire

*Tough Rubber Sheathed wire

*Poly Vinyl Chloride wire

*Lead Alloyed Sheathed wire

*Weather Proof wires

*Flexible wires

Types of cables

1. solid cable

2. coaxial  cable
3. flat cable

4. double stranded cable

6. multi stranded cable with a coaxial

7.multi stranded cable

Construction of a cable