Geek Trivia

Which Of These Countries Has The Safest Electrical Plug Design?

The United States
The United Kingdom
Which Ultra-slick Coating Was Discovered by Accident?

Answer: The United Kingdom

There’s a very good chance that you’ve used the outlet and plug system in your home country and never thought much about it. Outlets are located in walls, plugs are required to get the power to the things you want to use—be they Christmas lights or your laptop—you plug them in, and that’s that. But if you take a moment to step back from the familiarity of day-to-day life and look at outlets and plugs from around the world, you might be surprised to find significant variation and that the outlets and plugs used in the United Kingdom are remarkably well designed. Their outlets and plugs are so well designed, in fact, that it’s very easy to argue they have the safest outlet and plug design out there.

What makes it so safe? There are multiple design features on both the plugs and outlets that makes it incredibly hard to injure yourself without outright negligence or determination. First, the plugs are designed so that the ground prong is at the top of the outlet and the neutral and live prongs are located at the bottom, further, the neutral and live prongs are partially coated in insulation. This orientation ensures that if a plug is loose in a socket, not only will a conductive object that falls between the socket face and the plug likely not even touch the live or neutral prongs (hitting the ground prong instead), but if it does, it will hit the insulated portion of the prongs.

Second, the ground prong is longer than the other two prongs and actually engages a safety mechanism in the socket itself. When you push the plug in, the longer ground prong pushes on a shutter system in the socket that opens the slots for the neutral and live prongs (partially unseating the plug closes the shutters and stops the flow of power). Not only does that make using the plug itself safer, but it also makes it very difficult for children to accidentally shock themselves by inserting something into a socket. To do so, they would need to use a screw driver or similarly narrow and strong tool to push on the safety mechanism in the ground slot while simultaneously sticking something into the other part of the socket—a task that requires enough foresight and planning that by the time you’re old enough to pull it off, you’re (hopefully) old enough to know better.

Third, as the result of a design choice made back around World War II, all plugs have individual fuses inside them instead of relying on a fuse or circuit breaker in a centralized panel to provide the appropriate safety override. If the load on an individual plug is too high, the fuse pops.

Finally, the interior design of the plugs is quite clever. Although you can’t see it in the image here, if you look up a cut-away-view of the interior of a U.K. style plug, you’ll see the layout choice immediately: the interior wires are different lengths. The plug is designed so that if the cord is pulled on and the plug connections damaged, the live and neutral wires pull free first and the ground wire (which serves to protect the user of the device from being shocked) pulls free last.

All told, it’s a significantly more clever design on all fronts than anything else you’ll find in the world and, by any account, light years ahead of two prong designs and even three prong (with ground) designs. While things have continued for too long in the developed world for such standards to change, we’d certainly put in a hearty vote for the U.S. adopting the U.K. style outlet and plug system.

Image courtesy of Tiber/GrabCad.