What the heck does that third prong on a Western Hemisphere power plug do (the “ground”) if it isn’t necessary for all electronics?


Hell, I’ve even seen people rip them off to fit 3 prong plugs into 2 prong extension cords. I’m sure it’s not safe, but I dont know why and why they would be necessary sometimes and sometimes not.

In: Engineering

Double insulated is the answer, if it’s not double insulated the exposed metal parts of the appliance need to earthed, the earth/ground prong should never be cut off if it’s there it needs to be there

It’s a grounding wire to protect users and electronics from power surges. You’re right it’s 100% not a necessity, but the more power something uses the more I would recommend using it. It’s essentially a safety feature. I don’t know if you know anything about jumping a car, but one of the cables you attach to metal under the hood instead of the negative of the car you’re jumping, it’s the same concept as that. You’re grounding it so if too much power goes through it will have somewhere to go.

The 3 Prongs correspond to 3 different wires in the plug. The main one is the Live wire, in which the current flows through to go to the appliance. The second is a neutral wire which has no charge/current compared to the Live one. And finally the top prong is the earth wire which also has no charge, but is a form of prevention in the case of a surge of current through the plug and touches the metal casing, this allows for the current to be ‘earthed’ instantly reducing the current flowing.

It’s a safety feature on electronics that have a metal exterior, to prevent people from getting shocked, in case the wiring inside gets messed up and touches the case. It grounds the actual metal exterior. I guess it’s only necessary if you value your safety, LOL.

How and why it works is actually really interesting!


Some items have their own protections built in that keep you safe when things go wrong. Those don’t require a grounding wire. Other items are not made with protections so the grounding wire fills that role … to protest people, pets, and property. Removing the prong is a frankly asinine idea that may not kill you or me, or even anyone you will ever meet, but it does kill plenty of people every year.