10 May 2009

DIY'ers will be puzzled by British electrical standards

Electricity is supplied at 240v and ½ the amps here. This means that heavy-draw appliances like vacuum cleaners will be sporting a wire that is so thin it looks like it should be hooked up to a telephone. That at least makes sense; abandon hope if you're trying to understand the logic behind house wiring.

It is illegal in the entire UK to have a light switch or electrical outlet inside of a bathroom (with the exception of a special low-amp plug for electric razors). The switch must actually be near the bathroom door but outside of the bathroom. The only exception to this that you're allowed to have a cotton pull string attached to a ceiling switch inside the bathroom, so that there's no chance of creating a short while standing in some water.

From this, you might conclude that electrical standards are really strict, but you'd be wrong. Outside of commercial buildings, conduit is never used-- simple vinyl-clad cable runs through walls all over the country, supplying power to outlets and wall switches. So apparently it's OK to die by drilling into a wall and through a live wire, but not to shake off this mortal coil in the can; I guess they just don't want people hogging the bathroom. And don't get me started about the breaker box; no, just don't go there.


  1. I remember a similar amazement I felt looking at the death trap that is US wiring, the first time I went to see my sister in Schenectady, NY.

    Mains sockets 2 inches above the basin in a bathroom? Unswitched and unshuttered as well? Metal pins on mains plugs that look like they will catch fire if used for more than 100mW? But at least if you inadvertently connect yourself to 110V supply you are less likely to be killed.

    Try visiting Germany, where they do both at the same time: 220V supply in unswitched unshuttered sockets in bathrooms. And yet nobody seems to die while blow-drying their hair in the bathroom there either.

    Maybe it's all just a myth.

  2. Be fair now. English three-pin plugs, being separately fused and insulated over half the two bottom pins; with sturdy connections and the cords pointing down out of harm's way, and sockets that are switched and have live/neutral shutters, must have some advantages over other plugs that look like toys?

    Conduit IS used, though perhaps some old houses lack good wiring. That situation is apparent in most countries.

  3. apparently doesn't stop people from not using it. I can't speak to new construction, but I've been in lots of houses with significant recent renovation (more than just a bathroom redone) that don't use conduit. I suppose you could fault the contractors, but it's surprising to me there isn't an inspection required where such things would be caught and corrected.