What is the purpose of earthing and why earthing is important
Earthing is the process of connecting the electrically conductive part of the electrical equipment to the earth. The importance of earthing is that it can prevent overvoltage and current conditions, it will provide a proper path to the fault current, the fault current won’t damage the equipment if earthing is done. Earthing can provide protection to personnel and equipment, earthing can prevent the rise of the potential of the equipment parts rather than the live part.
If the metallic part of the electrical equipment makes a contact with the live wire then it could be dangerous to the person who would be operating it. This contact of the metallic part to the live wire can be caused because of the installation failure, or it can be because of the failure of the cable insulation. So to avoid this all the equipment needs to be earthed.
How to check if the earthing is properly done in our home?
We can do it in two ways either by using a lamp or by using a multi-meter.
Earthing check by using a lamp
Before starting the test we must know the basic thing such as the phase, neutral, and earth. If we look at our electrical switchboard in our home we can see the three-pin socket and we must be aware that which is the earth, phase, and neutral. The big pin in the three-pin plug is the earth, so in order to determine the phase and the neutral take a tester and insert it to the three-pin socket not in the big slot that is the earth, insert the tester to the other two small slots one after the other in the socket and if the tester glows then it is the phase and if not then it is neutral. A phase is called the live part because it provides the current.
We can also check it by using a lamp connect one of the lamp wire to the earth and the other wire to any one of the two slots, so if the lamp glows then it is the phase if not then it is neutral. In order to determine if the earthing is proper in our home to check this, we have to connect the lamp to the neutral and phase and by doing so the lamp will glow, connect the lamp to the earth and phase, and if it glows then the earth is connected if it glows at the same intensity as it glows in the phase and neutral connection then the earthing is proper. So that means the voltage is the same and the earthing is proper.
Earthing check by using a multimeter
Set the multimeter to AC voltage and set it high and connect it across the phase and neutral so that we can get the voltage. So we got the voltage value across the phase and neutral after that connect the multimeter across the phase and earth and if the value is the same then the earthing is properly done in our home. So it means that the earth’s resistance is proper. Then connect the multimeter across the earth and neutral and if the voltage is below 2 volts then the earthing is proper. If we get the voltage across the earth and phase is different from the phase and neutral then it could be because of the earthing problem or it can also be because of the load unbalancing.