Tom Scott runs a YouTube series simply titled “Things You Might Not Know.” Can you guess what it’s about?
His most recent video, which comes to us via Digg, extols the virtues of design and safety as manifested in a particular everyday object: the British electric plug. He explains his love for what might otherwise be considered a mundane part of every home appliance.
See the small red plastic “shutters” below? Outlets have these covers to prevent you from accidentally electrocuting yourself.
The only way to open the shutters is to plug in the larger “ground” prong of the plug first. This deactivates the shutters and lets you insert the other two pins. (In the UK, it’s not called “ground,” but “earth.”)
If you leave the plug hanging halfway out of the outlet, there’s no accidental risk of shock — the active pins are insulated (note their black covering) to keep you safe if you should somehow touch them.
On the inside, each plug has its own fuse in the case of a short. The blue and brown wires, neutral and live, respectively, are designed so that if there’s an aggressive tug on the plug, they will detach and fail first, leaving the green and yellow wire (ground) attached as a return route for the electricity, safely keeping it away from people.
The only flaw, as Scott explains it, is that if you drop the plug on the ground it will almost certainly land with the prongs pointing up, making it pretty hazardous for barefooted middle-of-the-night navigation.
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