| Answer 1: That's a really good question that I have never thought to ask. I'm assuming you're talking about the 3-prong outlets which fit plugs with 2 flat blades (on 'top') and one round pin (on 'bottom'). The two blades carry the current, and the pin is the 'ground'. The ground pin only carries current when there is a fault in the system. A fault is when something disrupts the usual flow of electricity through the circuit -- if one of the wires gets damaged, or something metal touches an exposed wire. In situations like that, the ground pin will carry the extra current away from the fault and to the ground (literally) which should prevent all the current from going into the fork that you're holding. This is why the 3-prong plugs are safer than the 2-prong variety, and also why you tend to see them in devices that are used outside, or around water, or in hospitals, which are all places where some moisture is likely to get into the device, causing a fault, and potentially giving a nasty shock to anyone who happens to be touching the device. So, why put the plugs upside down? The best answer I could find was on a message board for electricians, where one contractor suggests putting the ground pin facing up for this reason: if the plug isn't all the way into the wall (so that some of the metal parts of the plug are exposed) and you happen to drop something metal onto the exposed parts of the plug, it would be best for the dropped object to contact the ground pin (causing no damage) than the current-carrying blades (potentially causing a short-circuit). I suppose they don't want to take any chances in the hospital! So remember to always be cautious around electrical appliances and wires. Also, even 3-prong plugs won't always save you, you can still get some rather nasty shocks just from touching the insulated plastic around a 3-prong outlet. |