To connect the metallic (conductive) Parts of an Electric appliance or installation to the earth (ground) is called Earthing or Grounding.
Earth protective conductors
Main Earthing Electrode
Damage, Injury & Death Prevention
Some people have second thoughts about the need for grounding installation and extra construction electrical material, especially in large-scale residential or commercial projects. If you already use top-quality equipment and perform constant maintenance, why would you need earthing ?
The answer lies in the fact that life is unpredictable, and you should always prepare for the unexpected. The safety and earthing or grounding system comes simply, making your building and electric boxes shock-free at a very low cost.
These systems provide long life to equipment, the safety of the personnel, does not require any maintenance as well as reduces the maintenance cost. Sabo makes a chemical earthing system that provides a low resistance path in the ground to any fault & leakage currents and ensures the smooth flow of the ground dissipation.
The earthing or grounding of an electrical system plays a very important role in the stability and safety operation of the system. Though the earthing or grounding in an electrical system is always invisible physically & by its function we can feel its importance only with the problems in electrical systems with poor or no earthing system.
As per IEC 60364- Earth: The conductive mass of the Earth, whose electric potential at any point is conventionally taken as zero
As per IEEE standard 80:2000-“Ground– A conducting connection, whether intentional or accidental, by which an electric circuit or equipment is connected to the earth or to some conducting body of relatively large extent that serves in place of the earth.”
Equipment Grounding :
In the equipment grounding system, all non-current carrying metal parts are interconnected and then connected to the earth. This way firstly there is no potential or voltage between the non-current carrying metal parts and then secondly there is no potential difference between the earth and non-current carrying metal parts. Non-current carrying metal parts are such as- panel or enclosure body, metal raceway, cable channel, equipment body, or frame.
System Grounding :
In system grounding a current-carrying conductor is intentionally connected to the earthing system grounded. This intentionally earthed current carrying conductor is called a Grounded conductor.
This is the main concept behind Earthing, which is a process bonding noncurrent bearing parts of an electrical device or the neutral summit of the electrical organization to the earth through wires possessing minor resistance to flow of current.
Earthing Through A Water Pipe
Earthing Through A Water Pipe
We know that current flows from a higher to a lower potential. Any electrical appliance or any electricity line which has been connected to the earth is now at zero voltage. In the case of any overloading of current, the immediate discharge of electrical energy takes place to the ground, without harming the appliance or the user. Even if the insulation of the equipment fails, if it is earthed, the appliance is safe enough.
Rod Earthing :
This method employs hammering of zinc and copper rods of about 1-1.5 metres length and 12-20 mm diameter into the general mass of the earth. Successive rods are screwed together and this chain is tried making as long as possible for lowered resistance by the surrounding soil. The earth wire is tied and clamped near the summit.This is a very economical and quick procedure for earthing.
Chemical Earthing is the use of bentonite based or graphite based compounds along with earthing electrodes (a pipe or a rod) that helps in improving soil condition and reducing the soil resistivity.
These systems provide long life to equipment, safety of the personnel, does not require any maintenance as well as reduces the maintenance cost. Sabo make chemical earthing system provides low resistance path in ground to any fault & leakage currents and ensure the smooth flow of the ground dissipation
Copper Bonded Earth Electrodes
Copper Bonded Ground Rods
Gi Chemical Earthing Electrode
Gi Ground Rods
Pure Copper Earth Electrodes
To install the Chemical Earthing :
1. Make a hole according to the size of the earthing electrode
2. Dig earthing electrode into that Hole
3. A BFC(backfill compound) should be put around the electrode
4. Then push the soil around it
Keep in mind that after installation, there should be an ample amount of water pouring near the earth-pit.
The main reason for doing earthing in the electrical network is for safety. When all metallic parts in electrical equipment are grounded then if the insulation inside the equipment fails there are no dangerous voltages present in the equipment case.
SOIL RESISTIVITY = 2πLR :
R = Value of Earth resistance in ohm. Distance between the spikes in cm.
π = 3.14
P = Earth resistivity ohm-cm.
Earth resistance value is directly proportional to Soil resistivity value
Safety for Human life / Building /Equipment
Over voltage protection
Location of Earth Pit
Effect of grain size and its distribution
Effect of current magnitude
Major power station = 0.5 Ohm
Major Substations = 1.0 Ohm
Minor Substation = 2 Ohm
Neutral Bushing = 2 Ohm
Service connection = 4 Ohm
Medium Voltage Network = 2 Ohm
L.T. Lightning Arrestor = 4 Ohm
L.T.Pole = 5 Ohm
H.T.Pole = 10 Ohm
Tower = 20-30 Ohm
If the earth pits are close by, the resistance value will be high.
Soil plays a significant role in determining the performance of electrodes. Soil with low resistivity is highly corrosive. If soil is dry then soil resistivity value will be very high. If soil resistivity is high, earth resistance of electrodes will also be high.