"Sparks" wrote in message ...
Ello ;-)

I have an earth supplied by the power company - There is an earth wire
that
appears out of the bottom of the main power companies fuse where the main
cable comes in.

This is then connected to a black box, sealed with an electric company
seal
It then proceeds into my consumer unit - pretty straight forward
From a google search, I gather this is a TN-S system
All fine and dandy

(See the first picture here
http://www2.tsbcs.co.uk/electrics/electrics.htm )

I have nearly added a generator transfer switch to the equation.
(You can see it on the page above, all that is currently connected is a
cable from the mains in terminals to an isolator
I am planning of removing the meter tails from the CU, and shoving them
into
the bottom of this isolator (after the power company has come out to
remove
their fuse!)

I am a tad confused with the earthing requirements for this...

The instructions with this switch state I need a TT system. where the
earth
spike is connected at the generator end.

Also in the transfer switch, the neutral from the generator is connected
to
earth

Do I simply bang an earhting rod in the ground next to the generator, and
connect it to the generator's earthing point, then connect this earth to
the
CU, so I then have two earth's, one provided by the electricity company,
and
one provided by me?

Some advise would be greatly appreciated!

Sparks...



Ha Ha Ha !!!! Sorry. But I've got to laugh. Can I ask who told you this
is going to work ? For one thing, what feeds your consumer unit after your
swap over switch ?

There is no neutral on a generator supply, so how are you isolating the
phase / phase supply from the generator so that it doesn't back feed to the
existing domestic mains supply ? Sticking one phase from the generator into
the ground, would also mean you'd also have to stick the neutral side of the
existing consumer unit into the ground. This won't give you full 240 volts
supply unless the earth impedance is below 1 ohm between your generator
neutral/earth point and your consumer unit neutral terminal.

The only safest way to swap between domestic supply and a generator supply,
is with a proper 100 ampere break before make switch. Like the ones with
the big handle you'd see on an old Frankenstein movie. Does the unit you've
bought have an automatic contactor which is rated at 100 amps and has the
ability to completely break from the domestic supply before it makes contact
with the generator ? If it does, then you don't have to stick anything in
the ground and you can leave it as a safety device. You'd only have to make
the connections from the phase/phase supply of the generator to the existing
consumer unit, but through the swap over switch.

Have a word with the sparks that comes to remove the consumer fuse. He may
have a better idea of what's needed.

Good luck with it.


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