An earthing pin, also called a grounding pin, harmlessly absorbs electrical surges to prevent electrical shocks in the event of a short circuit. It transfers the power surge to a solid copper grounding rod that is attached to the main electrical panel by a single earth-grounding wire. Its main purpose is to reduce the risk of dangerous electrical shocks from uninsulated metal parts of an appliance or electrical device.
Since electricity follows the path of least resistance, an appropriately earthed electrical system and device discharges harmful power spikes to the soil safely.
The system protects electrical devices, such as home appliances, machinery and power tools, via a three-wire power plug. The extra pin, which is the grounding pin, is connected to the device's circuit protection system and harmlessly carries electrical surge away to prevent electrocution of users. On some appliances, a grounding wire must be fastened to metal water pipes to prevent electrical shocks.
Some three-pin plugs, also known as three-prong plugs, are arranged in triangular formation with two flat pins parallel to each other and one round pin located below. The round pin is the earth pin and transfers power surges into the grounding system built into the wall outlet.