Why is Earthing Necessary at Home? Let’s Understand
First, let’s understand what earthing is. Earthing means directing fault electricity straight to the earth through a low-resistance wire. It is part of an electrical network that functions as a safety measure. Its aim is to protect both equipment and users from electric shocks.
If your home is not earthed, you become a medium for the current.
When you touch the metal part of a faulty electrical installation or appliance, the electric current can flow through your body to complete the circuit, which can result in an electric shock—definitely unsafe.
However, if an earthing system is installed, when you touch faulty equipment, the current will flow through the grounding wire to the earth instead of passing through you. This keeps both you and your electrical equipment safe. An RCCB (Residual Current Circuit Breaker) is also installed with the earthing wire, which cuts off the power supply as soon as current flows through the grounding wire, keeping you safe.
How to check earthing at home?
It is very important for a building or home to have earthing installed. This process transfers any discharged electricity—meaning electricity that takes an unintended path—directly to the ground, ensuring safety in case of a faulty wire. If you want to check whether your home has grounding, follow these steps.
Earthing is found only in three-pin sockets. The largest outlet at the top is where the grounding wiring is connected. First, you need to take a line tester and turn the switch on.
Then, insert the line tester into the lower two outlets of the socket to check which one is the live wire. The outlet that lights up the tester is the live wire. In this process, you must touch the metal part at the back of the tester with your finger.
Next, take a light bulb connected to two wires, inserting one wire into the large outlet (the earthing hole) and the other into the live outlet, then turn on the switch. If the light bulb glows brightly, it means your home has proper earthing. If the bulb glows dimly or does not light up at all, it indicates that there is no grounding or there is a fault. For a more accurate test, you can also use a multimeter to take readings. This process is only for 5A sockets.
You should check how much voltage is showing on the meter. If it’s between 3V and 5V, it means there is no issue with the earthing. If it goes above 5V, it indicates a fault in the grounding.
History
During 1836-1837, German scientist C.A. von Steinheil discovered that the ground could be used as a return path to complete a circuit, eliminating the need for a return wire. Steinheil was not the first to do this, but he was unaware of earlier experimental work, and he applied this principle to in-service telegraphs, making it common knowledge among telegraph engineers.
However there were some issues with this system. In 1861, the Western Union Company constructed a transcontinental telegraph line between St. Joseph, Missouri, and Sacramento, California. During dry weather, ground connections often developed high resistance, causing the telegraph to malfunction or phones to fail to ring. To solve this problem, water had to be poured on the ground rod.
In the late nineteenth century, as telephony began to replace telegraphy, it was found that power systems, electric railways, and other telephone and telegraph circuits, along with natural sources like lightning, induced currents that caused unacceptable interference in audio signals. Therefore, around 1883, a two-wire or ‘metallic circuit’ system was reintroduced.
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