Friends, in this article you will be able to know how many types of earthing are there? 3 types of earthing are used in Electrical Installation as mentioned below.
- System Earthing (Neutral Earthing)
- Equipment Earthling
- Special Requirement Earthing
1. System Earthing ( Neutral Earthing)
System earthing is done at power generation centers (generating stations), and substations. Winding of the alternator winding of the generating station and secondary winding of the power transformer in the substation are done by making a star connection meaning their star point. Which is called System Earthing or Neutral Earthing.
The entire earthing system is protected because of system earthing. If any faults are created in the electrical system, then the Protection Devices located in that system are Activated. And separate the faulty section from the circuit. due to this reason earthing protects the instrument material and equipment located in the electrical system.
Example – If one conductor of the overhead line breaks and falls on the ground, then that conductor can prove to be extremely deceiving for the animals / humans communicating there.
If this happens, the safety devices are implemented in that circuit by faulting and isolating the part of the broken conductor from the power supply. Because of which humans / animals and equipment communicating there are saved from harm.
In the 3 phase system, the secondary winding of the distribution transformer is done by making a star connection that points earth. A neutral wire is ejected for the load from that earth point. This is called neutral earthing.
If the load is unbalanced in the 3 phase, then the unbalance current of that circuit goes into the ground through the neutral earthing. Because of this, the voltage balance of the three phase is reduced by maintaining the line and mean voltage differences.
Because of this, the devices located in that circuit are protected. This is possible only because of system earthing.
2. Equipment Earthing
The metallic part of an electrical device which is not used for the flow of electric current, or to connect the body of the equipment to the system earthing permanently and uninterrupted is called Equipment Earthing.
This is a type of earthing earthing known in our homes.
In order to protect the life of any electrical appliance and the human life working on it, it is very important to earthing that device. The resistance of the insulation used in the equipment decreases and leakage current starts flowing out of it.
This leakage current rotates continuously in the metalized part of the device, due to which the heat of the device increases and it is likely to burn. At such a time, due to equipment earthing, the leakage current goes into the ground, and the equipment remains safe.
If the insulation of the cable or wire that is electrically electrifying the device becomes defective for some reason, then the phase or live wire has direct contact with the body of the device, and electrical current begins to flow in the body of the device.
If a person starts working on that device, the person will feel a tremendous electric shock as soon as he touches the device. That person’s life can also be lost.
If the device is connected to the equipment earthing, then there will be earth fault protection devices (fuse / MCB) and disconnect the device from the power supply. As a result, the person working on that device will be safe.
If the conductor breaks or breaks in the middle for some reason, it is possible to make a living or financial loss as stated above while working on the equipment. If this is not the case, then for different protection, two different Earthings are made at two places for the metal body of the industrial equipment.
Which is called double earth. If one of those earing becomes inoperative then the equipment is protected from the other earthing.
3.Special Requirement Earthing
Static earthing is done in some specific places to protect the tall buildings from Static Charge (Lightning).
Large buildings and operation theater of the hospitals are installed in lightning conductors to connect them to the earthing.
They are also interpreted by installing Lightning arresters on the over head line.
Due to which the discharge of celestial electricity goes through the earth conductor into the ground. And thus high buildings and over head lines are protected.
Elsewhere, clean earthing is done for computer data processing equipment. Which connect independently to the computer system. Clean Earthing means any earthing that is used for only one device, and not in contact with commonly used earthing.