Earthing

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.”

There are several types of earthing systems used in electrical installations, each designed to provide safety and dissipate fault currents. Here are some common types:

1. TN System:
   - TN-C (Combined): Uses a common conductor for both protective earth and neutral, up to a certain point, and then separates them.
   - TN-S (Separate): Has separate conductors for protective earth and neutral throughout the entire installation.

2. TT System:
   - In a TT system, each electrical device is individually grounded to the earth, providing local grounding at the point of use.

3. IT System:
   - In an IT system, the neutral point of the power source is connected to the earth through a high impedance, providing limited fault current flow.

4. TN-C-S System:
   - A combination system that uses a combined neutral and earth conductor (TN-C) in distribution networks but separates them (TN-S) at the point of use.

5. Floating Ground System:
   - Also known as an ungrounded system, it isolates the electrical system from the ground, allowing continued operation with a single fault.

6. Grounding Electrode System:
   - Involves connecting various electrodes like rods, plates, or grids to the electrical system to ensure a low-resistance path to the ground.

7. Resonant Grounding System:
   - Utilizes a reactor to limit fault current and maintain system stability during ground faults.

The choice of earthing system depends on factors such as local regulations, the nature of the installation, and the level of protection required. It's crucial to follow electrical codes and standards to ensure the safety and proper functioning of the system.