Home electrical system

[desertrat]

I went around an elderly relatives house and rewired all of her plugs as some of them even from the outside looked decidedly dodgy as she had a habit of doing them herself even though she has very poor eyesight and severe arthritis. Surprisingly when I checked the plug on the TV even though one plug had the live wire connected to the correct pin the negative was connected to the earth and the TV still worked. Is there a fault in the house electrical system?

[Michael H]

The circuit would work as you describe, not because of any particular fault in the house wiring, but because the negative return and the earth will most probably be connected together at the main distribution panel. Don't ask me why. I dicovered this to be the case in the building where I live and It puzzeled me too.

[norfolk boy]

The power to a tv go's through a trans former.As the resistance of the windings is high enough you won't get a dead short.On most households nowadays your earthing will more than likely be a tnc-s system which in laymans terms is a combined neutral and earth at the fuse box.

[thecooler]

TVs are powered by a switch mode power supply with live mains on the circuit board - no transformer. So you'll have to come up with a better explanation than that!

[norfolk boy]

Youv'e got me there cooler,it seems tellys have come on a bit since my day!

[Disco Fever]

At the transformer, somewhere near your house, Neutral and Earth are bonded together which is called the Star Point and thats why the tv worked connected to live and earth. But now a days you have a P.M.E. supply which means Protective Multiple Earth and the Neutral and Earth are bonded together where your cut out fuse is in your house. Easy when your a sparky innit.