PDA

View Full Version : What On Earth.......


acbus1
7th Nov 2005, 16:51
The Water Board (or whatever they're called these days) are going to rip up the old mains and replace with wonderful shiny new plastic.

Trouble is, they say this won't act as an electrical earth for the wiring in our house. They say it's our responsibility to check and sort it.

I see mucho money dissapearing down a big pit. :uhoh:

Does any one have experience of this, please?

(Free of charge, please. Good conduct. Quick as a flash. I'll offer no resistance. Safety in the ohm and all that.)

Farmer 1
7th Nov 2005, 17:07
Are they going to rip up the pipe which actually feeds into your house? If not, I don't think it will change anything.

If yes, then you will need to do something, like get an earth spike, which should not be expensive.

I'm not an expert here, just a pilot, you understand, but you do need to ask for professional advice. I would imagine (and sincerely hope) that the water board would give out the information before they start doing the work.

The laws on electrical fittings are being changed on a daily basis, so I say again, professional advice is necessary, I'm afraid.

tony draper
7th Nov 2005, 17:13
Yup a large copper spike driven into the earth will surfice,lecktricy loves the earth yer see,
frankly one does not understand why they did not do away with earths years ago, they can be a menace.
:cool:

acbus1
7th Nov 2005, 17:14
Thanks, Farmer 1 and Monsieur D. :ok:

That raises another question.

There was a thread recently about the new regulations for anyone working on domestic electricity installations. Basically, if I got it right, only qualified people (so called) allowed to do any work with prior survey and approval of the Local Government Council Jobsworths.

Wondering if this will rear it's stupid head as well..... :uhoh:

Farmer 1
7th Nov 2005, 17:23
You could be right, but don't despair just yet. If the work needs to be done, you will obviously not be the only victim. I just cannot believe a water board would be permitted effectively to make a death trap of a large number of houses.

Even the jobsworths are aware of just how dangerous the electrical stuff is.

markflyer6580
7th Nov 2005, 19:49
The waterboard in my neck of the woods (yorkshire water) are useless, old pipe burst on the small green in front of my house on sat eve. As I write this there is still a six inch high fountain coming from the ground my car is stood in about kerb height water(not ideal when trying to get in it without getting wet). I'm no tree hugging hippy mentalist but there are people in the world with nothing to drink and we have it spraying from the ground,what a waste:mad: I rang them today to ask what was happening and they said it would be fixed this week! What are they on:mad:

gas path
7th Nov 2005, 20:55
................wanders back after taking a peek at this house, and lo and behold its earthed to the gas main!
So, if convenient, why not run a 10mm earth cable to the gasmain? upstream of the meter of course!

edit to add; the above is no good if the incoming gas supply is plastic:uhoh:

Grainger
7th Nov 2005, 22:38
. . . earth cable to the gasmain . . .Yikes ! Electricity and gas :eek: - this to me is not a good combination. One spark and . . .

What you always used to do is get an old biscuit tin, solder a good length of 1/2" copper braid to it and connect the other end to your domestic earth. You then go out into your back garden and bury the tin in the - ahem - earth. That should do the trick. Eventually the tin rots away so you'll need to replace it every ten years or so.

M.Mouse
7th Nov 2005, 23:10
We are getting a little confused here. My knowledge of electrical wiring practice does not go back far enough to know what the policy USED to be but certainly in the past 30 odd years it is not the water main, or gas main, being used as an electrical earth source but BONDING of the water, and gas main, to the house earth source.

The house earth source is either supplied by the earth sheath on old underground electricity board main supplies, or an earth stake where a house has an overhead supply with no earth continuity conductor or the dreaded Protective Multiple Earth conductor which is an earth terminal connected directly to the neutral of the supply cable....NO don't ask for an explanation the answer will have you rolling in the aisles, PME can be very dangerous in my eyes.

The modern terminology has changed a great deal but I believe what I have written is basically correct....unless anybody knows differently.

BombayDuck
8th Nov 2005, 02:43
drapes

frankly one does not understand why they did not do away with earths years ago, they can be a menace

Can you (or anyone else) explain that please? I didn't get it.

Farmer 1
8th Nov 2005, 05:39
I hope no one does away with my Earth, I'm rather attached to it.

Loose rivets
8th Nov 2005, 06:11
(I get to the question above after initial ramble)

EDIT I should say that at the time I sold my home in Essex there was no requirement to tie the incoming Earth to any other underground pipe or rod. If this has changed, please someone pipe up.(groan)


We had a huge thread running on this subject a year ago or so. It seems that wile I'm in Texas I had darned well better be grounded...or else. But in the UK the cable that comes into the house is covered in a sheath of think strands. This sheath is Earthed by the powers that be. (Sorrreeee, couldn't resist it....oh, dear, oh dear.)

It is required to set a datum for one's Earth. Once this sheath is deemed to be ‘solidly connected to the suppliers Earth' then this is you datum. You now have to ensure that all your pipes in the house are ‘tied' to this datum. This is the tricky bit. Connecting them via several routes is a formula for trouble. Small voltages appear that cause accelerated corrosion of said pipes. So, the bonding of pipes has to be done by the book.

Also, I think we agreed that all Earth pins had to come back to the meter in an approved manner...again so as not to create loops.

In your case, all this should be done. You just have to ensure that the house Earth system is indeed connected to the incoming braid. There is a good chance that you will be able to do this by just looking. If not, a digital volt meter should show no more than a small fraction of a volt between your earth system and this braid. WHILE SUBSTANTIAL LOADS ARE IN USE.

There should be no more than a couple of volts between your Negative line and Earth. Don't do this testing if you are not totally confident that you won't zap yourself.

Now, the need for Earths. I agree wholeheartedly with TD on this. Earthing was always the lesser of several evils. It nearly killed my daughter. Very, very nearly. Modern electronics did away with the need for Earthing 15 or more years ago.

All houses should be protected by RCDs or RCCBs or whatever they are called now. They monitor the current on the live and neutral wires, and if they see a difference of, typically 35 milliamps, they will open a set of contacts in a small fraction of a second. The chances are that the person trying to ground the mains with their wet pinkie will not feel anything.

I think that these devices are the single best invention since the wheel...BUT...they do not protect against anyone trying to be a light-bulb. If you are determined to grab hold of live and neutral, these things will not know the difference between you and any other load.

There are breakers now that detect patterns of arcing. The analysis is made on a chip in the circuit breaker. Quite spectacular. I don't know if they are available in the UK. Strange to think that this $30 device might have saved the Queen's castle a while back.

arcniz
8th Nov 2005, 07:54
One context where power system earths pay for themselves is when lightning is folicking about.

In arid climates, direct earth connections sometimes gradually fail to operate properly as the season shifts from damp to dry. Individual buildings can develop very large voltage voltage differences between them. Plays havoc with telephone lines - that use earth circuits to drain off static, and electronics such as computers with lots of interconnection and sensitivity to small signals. If one happens to have a transmitting station of a few hundred or a few thousand watts, the whole neighborhood can glow in the dark when the earth grounds are dry and xmit goes active.

acbus1
8th Nov 2005, 08:00
the whole neighborhood can glow in the dark when the earth grounds are dry and xmit goes active.

Bit like Sellafield then, 'cept they've got two headed sheep as well. :\




Erm, thanks to all, but some of this is a bit technicologibble for me......I never did understand electrickery (no-o-o-obody mention aircraft 3 phase or oil tump yer).

I've printed it all out so far for deep deliberation and no doubt much use of coloured highlighter and tears (as opposed to tears). :ooh:.......

Keep it coming......:ok:

BombayDuck
8th Nov 2005, 10:05
Ah Loose Rivets I know what yer talking about! We call them ELCBs (Earth Leakage Ckt Breakers) here. Not as commonplace as they should be, and yes, 30 mA differential is what they're rated for (at least the ones at me home).

That makes sense of why you'd want to not have a ground.... but unfortunately out here not enough people have ELCBs installed to get rid of this. Though I dont know enough cases of the ground/earth fouling things up, I guess it does happen.

tony draper
8th Nov 2005, 10:12
One came up with a cunning ploy once,one would hammer a very long earth rod into ones back yard with a better earth potential than earth itself, and a slightly shorter one at one front door thus intercepting and using all ones neigbour lecky free of charge as it makes it way back through earth to the generating point, twas fraught with technical difficulties though.
:(
One has had more electric frights in ones working life than one can shake a stick at,overhead high level link audio feed was the worst the fecker could peak at 600 volts,used to tickle you a tad on a wet day that did, we practiced one hand gripping ladder rung working for oneself tother hand working for the company in those circumstances
:uhoh: