Protection from Overvoltage and Current: Earthing prevents overvoltage and excessive current conditions. It offers a designated path for fault current, ensuring that such current doesn't harm the equipment.
Safety for Personnel and Equipment: Earthing enhances safety by preventing the potential rise of equipment parts, especially when compared to live parts.
When the metallic component of electrical equipment comes into contact with a live wire, it poses a significant danger to anyone operating the equipment. Such contact can occur due to installation errors or cable insulation failures. Proper earthing is essential to avoid this risk.
Different Types of Earthing
Earthing comes in different forms, including neutral, ground, and phase earthing. It's essential to understand the distinctions between these types.
Neutral Earthing: This type of earthing involves connecting the neutral conductor to the earth, ensuring safety and stability.
Ground Earthing: Ground earthing connects the equipment's conductive parts to the Earth. This safeguards against electrical faults and hazards.
Phase Earthing: Phase earthing focuses on the phase conductor and its connection to the ground. It plays a crucial role in maintaining electrical system stability.
How to Verify Proper Earthing in Your Home
Checking whether your home's earthing is done correctly can be done in two ways, using either a bulb or a multimeter.
Earthing Check Using a Bulb:
Before conducting the test, it's important to identify the phase, neutral, and earth connections. In your electrical switchboard, you will find a three-pin socket, where the big pin is the earth. To determine the phase and neutral, use a tester. Insert the tester into the two small slots, one after the other, and observe whether the tester glows. If it does, it indicates the phase; if not, it's the neutral. The phase is often referred to as the live part because it carries the current.
Alternatively, you can use a 100 W bulb. Connect one bulb wire to the earth and the other to one of the two slots. If the bulb glows, it's the phase; if not, it's the neutral. To check proper earthing in your home, connect the bulb to the neutral and phase. If it glows, your earthing is connected. If it glows with the same intensity as it does in the phase and neutral connection, it signifies proper earthing, meaning the voltage is consistent.
Earthing Check Using a Multimeter:
Set the multimeter to AC voltage and adjust it to a high setting. Connect it across the phase and neutral to measure the voltage. Then, connect the multimeter across the phase and earth. If the voltage is the same, your home's earthing is correct, indicating proper earthing.
Finally, connect the multimeter across the earth and neutral. If the voltage registers below 2 volts, it confirms proper earthing. However, if there's a significant voltage difference between the earth and phase compared to the phase and neutral, it might indicate an earthing problem or an issue with load balance.
In summary, earthing is a critical safety measure to protect both individuals and equipment from electrical hazards. Regular checks using simple tools like lamps and multimeters can help ensure that your home's earthing is in good working order.