Earth rods...do i need one?

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I live in a row of small granite houses, the doors all open straight onto the pavement and wandering home the other day when i noticed almost all the other houses have a copper rod and wire arrangement outside the front door. Intrigued i had a look round my house and the only earthy looking thing is a green/yellow wire from the fuse box to the gas meter pipe...The electrics are fairly old (probably 1970's) .... I've seen earth straps from water pipes in others houses but i don't seem to have any either...what are they for? what is the rod for?...
 
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The earth rod is required if you have a TT earth system. Can you photograph and put a picture of your main fuse and meter position on here? There is a high chance if your neighbours are on a TT earth then you should be too. However there is a possibility that they are all old and now redundant, and the DNO have now supplied a PME earth connection. A picture should tell us this.
 
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If you have an old house there may be a voltage operated earth leakage trip (ELCB-v). These units will fail to operate if a second earth is added so you need to be careful adding extra earth wires to an old system.

With the newer current operated earth leakage trip (ELCB-c or RDC) where fitted because you have an earth rod (Called TT) the trip is often 100ma rather than very new where we have at least two 30ma although a 100ma RCD could be fitted for other reasons having a 100ma RCD or an old ELCB-v would indicate likely on a TT system.

In days gone by it was common to use the water pipe as an earth but because of plastic piping this was banned however the water pipe and gas pipe are still connected to earth in real terms the banning of using water pipes as an earth really meant it changed it's name from earth electrode to extraneous-conductive-part however I have seen the connection removed in the past because people did not understand that when we say water and gas pipes should not be used as an earth it means in real terms "Only Earthed item" there should also be a dedicated earth.

I have in the past fitted earth rods under the floor boards where no front or rear garden so yours could be hidden some where. Earth rods should not be where one can touch them as under fault conditions it could be dangerous. However back in the days of party line telephones the post office fitted earth rods for the telephone these are now obsolete but you still find them about and are nothing to do with power to house.

The electricity supplier (DNO) can if he wishes supply you with an earth connection but he is not forced to however he is obliged to tell you what system you have. There are in essence two systems TT (needs earth rod) and TN (DNO provides the earth) the latter is sub-divided into TN-S and TN-C-S the latter is also know as PME as far as you are concerned it makes no difference. It will make a difference to an electrician testing as he looks for different readings but not to house holder.

Often the DNO will stick labels on the head where power comes in saying PME or TN-C-S which is why I have given those letters. Where the supply is underground then often you do get an earth provided although not always and where the supply is aerial often an earth is not provided again not always though.

As the others have said pictures is the easy way. A phone call to DNO asking what earth you have would likely also help as often they can't tell you and have to send some one out. Although they will not fit an earth rod they would tell you it all looks OK or some thing is wrong. However I have found that if there is a earth wire ready for them to connect to they will often connect it so saving a fee latter to convert to TN-C-S so could be better to get an electrician first.

I look forward to seeing pictures.
 
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Well for what its worth here it is, its to the right of the front door and up high. I must admit it just looks like a rats nest of killer electricity to me! The green wire goes down across the door frame to the gas pipe/meter which is on the floor the other side of the porch...
 
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where does the green/yellow wire disappear off to? That could be your main earth as it comes inside with the incoming cable.

Does the ELCB (black switch) trip when you press the yellow button?
 
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Well for what its worth here it is, its to the right of the front door and up high. I must admit it just looks like a rats nest of killer electricity to me! The green wire goes down across the door frame to the gas pipe/meter which is on the floor the other side of the porch...
Assuming that what we're looking at there is an "ELCB-v" (as described by eric), it looks as if it may well be missing one of its earth connections.

When you refer to the 'green wire', do you mean the one at the bottom of the picture, or the yellow/green one at the top? If the former, do you know where the yellow/green one at the top goes to?

Kind Regards, John
 
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Beat you again! Ahah!
Damnit :) ... but you didn't mention the VOELCB ;) . I would have thought that it's second earth connection ought to be at the top (where it clearly isn't), but it's just possible that there are two down the bottom. I'm not sure what those test buttons do/did, and therefore couldn't be sure that they wouldn't result in a trip even if the earth connection was missing, could you?

Kind Regards, John
 
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Do you have only one circuit for the house or is there another consumer unit located somewhere off camera?
 
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Do you have only one circuit for the house or is there another consumer unit located somewhere off camera?
If he did have and other CU, there's no obvious way that it could be fed, is there (unless by that T+E at the topof the pic!)?

Kind Regards, John
 
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Presumably if you are happy to allow half-a-dozen 3rd party sites to run rampage on your PC with scripts you know nothing about you can get a bigger photo - if so, does it show 2 earth connections?

Mind you, with no earth rod, where would one of the two wires go?
 
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Mind you, with no earth rod, where would one of the two wires go?
Quite, although it would have taken a bit of an idiot (at least, one who didn't understand how the devices worked) to install a VOELCB if there hadn't been an earth of some sort to connect to it (even if only a service pipe) at the time, wouldn't it?

Kind Regards, John
 
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I see no evidence of a general shortage of idiots doing electrical work.
True, and I suppose that was even true in the past (when people tended to be 'properly trained') - I would presume that must have been installed 30+ years ago?

Kind Regards, John
 
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