My Gran asked my uncle to have a look at her electrics after my Grandpa passed away...
... All seemed fine except for a mysterious white plug that disappeared behind the T.V but didn't seem to be connected to anything. Getting on his hands and knees he followed the wire behind the T.V, under the carper, out the room, across the hall and into my Grandpa's bedroom. By moving the bed my Uncle found what the plug was connected to; an identical white plug connected to the mains. For some reason known only to himself my Grandpa felt it necessary to hook the mains up to the mains.
(Ash_Pow is now available in extra medium, Thu 20 Aug 2009, 13:12, 7 replies)

Interesting
Could it be that he knew there was a defect in the ring main, or an under-rated spur? This could have been an unusual and creative attempt to avoid an electrical fire, caused by a heavy load where the existing fixed wiring couldn't stand one. But this is the first I've heard of someone actually connecting wiring in parallel like this.

That said, I've heard of people starting fires by connecting the entire domestic load through one socket and a shipload of power strips; in the misguided belief that this would lower their electricity bill.
(The Incredible Sulk Finally remembered his password on, Thu 20 Aug 2009, 13:18, closed)

Wire with plugs on both ends
Not a good idea.

Exposed live pins and all that.
(karnuvap, Thu 20 Aug 2009, 15:44, closed)

yup
I hope I didn't appear to support the idea - it's a safety disaster area; which would probably cause more problems than it could solve.

Even if you leave it plugged in, avoiding contact with exposed live pins; you could have a patch across two circuits, which could mean a circuit you think you shut off at the distribution board is still live (electrocution, death). Also, if one fuse/breaker trips out, you could have over 13A drawn down one small cable in a vain attempt to feed the whole other circuit (overheating, fire) - think of shutting down a section of the M25 and routing it down a C-road.

It would be even more dangerous in places with tri-phase supplies; hook one up to the other and I think you could get voltages exceeding an already lethal 240V (consider how you can get 415V machinery running off three "ordinary" 240V supplies).

There are other possible interpretations, but neither explains its location well:

This might be a crafty piece of hardware for stealing/borrowing electricity, plugged into someone elses supply and also into yours. If you kept your main supply switch off, and your total load below 13A per patch cable, this might work.

Alternatively, it could be a means to legitimately supply power to a caravan. Plug one end into domestic socket, the other into a socket in the otherwise electrically-isolated caravan, and you've just energised the caravan supply (although again limited to 13A per cable, this could be enough - a fridge, some lights, and you're all good).

Disclaimer: I am not a qualified electrician. Don't try this yourself, you may die or worse.
(The Incredible Sulk Finally remembered his password on, Thu 20 Aug 2009, 20:55, closed)

My Welsh great uncle did your caravan trick...
...plus a few home lightswitches, bell-wires, etc, to supply his barn. Until the system electrocuted (luckily not TO DEATH) my dad, who then spent a week installing a proper ring main, waterproof sockets, etc, while my great uncle continued to maintain that it was perfectly safe and my dad was a numpty Englishman.

20 years later, my Indian stepmum's uncle's insane home-made electrical wiring put 240 volts through me while I was trying to fix his computer. Given the way I was standing, if it wasn't for my rubber-soled shoes I'd be TEH DEAD. Obviously, myuncle continued to maintain that it was perfectly safe and I was a numpty Englishman.

Conclusion A: eventually, everyone who isn't English will end up electrocuted due to their dodgy wiring
Conclusion B: foreigners deliberately set up their wiring in the hope of killing Englishmen
(stalinism, Fri 21 Aug 2009, 13:43, closed)

What got me
was when they did this on an advert- it was British Gas or Scottish Power or something... they had a windfarm on a planet and a house on a planet and linked to windfarm to the house using a normal domestic style socket. But the power was coming from the plug end- so you'd have had live pins

I complained about it but nobody listened...
( uberdeity Wondered why Owen Lars knew of the term "hell" on, Fri 21 Aug 2009, 18:04, closed)

I've found
that things like this are either done by idiots or geniuses, and it usually takes a while to tell which.
( Sextant goes to him is emotionally erect, on this day, Sat 22 Aug 2009, 10:50, closed)

I just had my room rewired...
And it got me thinking. Maybe your Granpa's house was wired with a radial circuit, and he was rigging it to be a ring circuit?
(Spiked_Rycroft The Prodigal Son, Thu 27 Aug 2009, 10:29, closed)