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Can we do away with earthing?

Adam Seddon

Had a discussion with my colleagues at work today around the theory of removing all earthing.

This is my question:

If I poke my finger into the live terminal of a 230v socket, the line current travels through me, through the floor (earth), back through the earth to the supply transformer (because the transformer star point is also tied down to the general mass of earth) the fault currents travel back into the transformer star point and hopefully the completed path is of low enough impedance to be able to blow or trip the protective device serving the socket I touched.

Now. If the transformer star point WAS NOT connected down to earth, there would NOT be a return path from the socket I've stuck my finger in, back into the star point of the transformer and I wouldn't be able to recieve a shock as there is no complete return path.

Is that correct or not?

So following on from that, my question is: why cant we just isolate all transformers from earth and remove the risk of a "line to earth" shock? After all, this is exactly why we use SELV transformers in bathrooms no????

Obviously you could still get a line to neutral shock, but that's got nothing to do with the question I'm asking here.

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    I suggest you visit South America or parts of Africa and look at the wiring - the answer is yes, we do not need earthing at all,  but its not at a safety level we would normally accept, being single fault to danger.

    Yep, its a shower, yep the red wires are carrying mains to it, yes the joins are just tightly twisted and taped. Its OK, just don't raise your arms up or turn the water up so high you get an unbroken stream.

    UK wiring regs however have required earthing for new power circuits since 1939  (example of pre 1939  2 pin plug - plenty still in service during my childhood in the late 60s early 70s)  and lights since 1969 or so.

    Mike

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    I suggest you visit South America or parts of Africa and look at the wiring - the answer is yes, we do not need earthing at all,  but its not at a safety level we would normally accept, being single fault to danger.

    Yep, its a shower, yep the red wires are carrying mains to it, yes the joins are just tightly twisted and taped. Its OK, just don't raise your arms up or turn the water up so high you get an unbroken stream.

    UK wiring regs however have required earthing for new power circuits since 1939  (example of pre 1939  2 pin plug - plenty still in service during my childhood in the late 60s early 70s)  and lights since 1969 or so.

    Mike

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