The two terms, ‘earthing’ and ‘grounding’ have been interchangeably used so much so that it is possible for people to get confused between the two. First of all, if you are under the assumption that both these are same, then, please get the facts right, they aren’t! We’ll dissect the terms and the symbols for them for you here.
Earthing means connecting the dead part which is the part which does not carry current under normal condition to the earth. For example, electrical equipment’s frames, enclosures, supports etc. On the other hand, Grounding means connecting the live part, the part which carries current under normal condition to the earth. For example neutral of the power transformer.
Both of them serves different purposes as well. While Earthing is generally done to reduce the risk of receiving an electric shock while touching the metal parts of an equipment when a fault is present, grounding serves another purpose. It is done to prevent the equipment and to provide an effective return path from the machine to the power source.
Now, the symbols used for both of them are also distinctly different. The “ground” symbol (Power Ground) to represent the net attached to a universal zero reference voltage, has always been a pile of three horizontal lines decreasing in length downwards. There is also now a symbol representing the open triangle pointing downwards (Signal Ground) as well as a symbol with what looks like a leaf sweeper, a horizontal line with three diagonally placed lines, relatively downwards (Earth Ground). The Earth Ground representing the connection to the earth in places like water pipes and represents the conduction of lightning safely to the ground.
Here are the symbols for all the terms that might be confused with one another. These are all distinct concepts that serve different purposes in electrical circuits.
Do share with your friends and let them also know of these differences.