Earth rod

[mickys86]

Hi guys. I've been reading a few posts about earth rods. What's the preferred way to join them, and also when installing a few of them what is the preferred way to link them? I've read some posts that says when installing them next to each other you should spread them apart the same distance as you go down. But none to answer my above question. Cheers

 

[mickys86]

At college when we asked questions like this all we got is we don't need to know. We watched one video a couple of years ago on how to test tt stakes but when asked to explain it again the tutor said don't worry about it, it won't Be in the exam. I guess their job is to just get us qualified

 

[huntos33]

So what advice do you give to someone on paye who has been given 1 earth rod to put in and only having a mft to test with. I tested Ze (my next question soon will be what's Ra) and the value I got was 179ohms. When I told my boss he said its below 200 so it's allowed......

When you join the rods do they clamp together or screw into each other? Because the rod that is in is just 1m copper rod. I need sound advice so I can learn something and also do the job right.

I have only ever used 1 rod and a mtf thats my point, i have never been told any different or trained any different would have no idea how to test RA which i would assume is the resitance of the rod to the earth around it , never done any different to you. you're best to ask the sparks doing it the right way i can see my 17th edd refresher and my 2391 course coming up to be real eye openers. Strange how the domestic world is so differnt to comerical works where you never see TT , well i hav'nt and hardly ever a RCD as is all in trunking conduit etc, so im learning to.

 

[trev]

So what advice do you give to someone on paye who has been given 1 earth rod to put in and only having a mft to test with. I tested Ze (my next question soon will be what's Ra) and the value I got was 179ohms. When I told my boss he said its below 200 so it's allowed......

When you join the rods do they clamp together or screw into each other? Because the rod that is in is just 1m copper rod. I need sound advice so I can learn something and also do the job right.

If you're given a little twig of copper you can always say what I've said in the past, "with a little bit of effort and a few quid we can get TN levels" usually that makes people sit up and take notice. If they don't well you're not signing the job off so it's their butts on the line, and anyone who thinks 200 ohms is ok is a fool.
As far as joining the rods, the ones I have used are threaded at the ends and there's a coupler to pick up with them. Drive the first one, screw on the coupler, screw on the second rod and start driving again. Rinse and repeat as necessary.

 

[trev]

Testing Ra is in GN3 mate go have a read it's not difficult, just a little time consuming.

 

[Deleted member 9648]

If you're given a little twig of copper you can always say what I've said in the past, "with a little bit of effort and a few quid we can get TN levels"Fine if you DO get TN values....but most on here dont,most seem to think they are the dogs danglies if they get 20-30 ohms,as yet nobody on here has ever given a valid reason why 30 ohms is any better than 200 ohms. usually that makes people sit up and take notice. If they don't well you're not signing the job off so it's their butts on the line, and anyone who thinks 200 ohms is ok is a fool......Would be great if you could give some examples of any actual instances of <200 ohms resulting in a dangerous situation on a UK TT system.....
As far as joining the rods, the ones I have used are threaded at the ends and there's a coupler to pick up with them. Drive the first one, screw on the coupler, screw on the second rod and start driving again. Rinse and repeat as necessary.

Posted by a fool.:waving:

 

[trev]

So basically wirepuller your red additions completely agree with the post of mine you have quoted.
However, rather than debate how your opinions may contrast with mine you resort to childishness. Makes me a little sad to say this but you're the first member on my ignore list

 

[richy3333]

So how low would you get it ? i mean there has to a limit when you stop banging in rods ?

Around here it's when your too knackered to bang any more rods in Soil condition will play a great factor and if at all possible get someone else to put them in the ground for you!

 

[huntos33]

so whats the conclusion ? 1 rod that passes the quoted 200 ohms is wrong or right ? or do we just keep on banging in rods at 10 quid a shot untill we cant get any lower ?

Not being sarcstic just wondering.....

 

[Guest55]

So basically wirepuller your red additions completely agree with the post of mine you have quoted.
However, rather than debate how your opinions may contrast with mine you resort to childishness. Makes me a little sad to say this but you're the first member on my ignore list

I thought wirepuller raised a couple of valid points , hardly worthy of spitting out dummy.
And could ou expand on the " anyone who thinks 200ohms ok is a fool " bit ?
You obviously know something we dont.

 

[trev]

200 ohms is not a stable Ra mate, my point is what will happen to that reading if/when the ground dries out completely?
I don't agree that I've spat out the dummy at all, I have never resorted to mudslinging on here and never will, if I disagree with a post I will say so and explain why I disagree

 

[Deleted member 9648]

So basically wirepuller your red additions completely agree with the post of mine you have quoted.
However, rather than debate how your opinions may contrast with mine you resort to childishness. Makes me a little sad to say this but you're the first member on my ignore list

You well knew my opinions on Ra values when you stated anyone who thinks the Bs 7671 maximum value of Ra is ok is a fool.... Calling someone a fool is hardly a good starting point for a debate is it?
More than happy to be on your ignore list mate...but you aint on mine,I'm not that childish.

 

[Engineer54]

Shall i jump in here, on this debate?? ...No i just can't be arsed!!

Save to say, that anyone here that has little to no experience of installing TT systems shouldn't be discouraged from creating the best system they can, by those that won't have a bad word said about the numbty 200 ohm Ra because it's stated in BS7671!!! This forum should be encouraging/promoting these and other electricians to install decent ''Working'' TT systems, when and wherever possible, and not telling them to stop at 200 ohms or whatever, cause that's what it Say's in their bible!!

Most of the rods sold and installed in the UK to electricians are in fact these useless 3/8'' twigs, that can't even be extended, these things have just got to be got rid of Full Stop!! When i first came into this game, Rods were all extendable 6 and 10 footers by 5/8 or 3/4''. to this day i've never actually seen a 1.2m rod of any size and i've probably be responsible for putting more rods in the ground over the years (well over 400 on my present project alone) than anyone else here. ...lol!!

One last word, what would any of you rather have, a coupled stable 30 ohm rod or a 200 ohm unstable single rod?? It's a real no-brainer isn't it?? lol!!!

 

[GLENNSPARK]

Shall i jump in here, on this debate?? ...No i just can't be arsed!!

Save to say, that anyone here that has little to no experience of installing TT systems shouldn't be discouraged from creating the best system they can, by those that won't have a bad word said about the numbty 200 ohm Ra because it's stated in BS7671!!! This forum should be encouraging/promoting these and other electricians to install decent ''Working'' TT systems, when and wherever possible, and not telling them to stop at 200 ohms or whatever, cause that's what it Say's in their bible!!

Most of the rods sold and installed in the UK to electricians are in fact these useless 3/8'' twigs, that can't even be extended, these things have just got to be got rid of Full Stop!! When i first came into this game, Rods were all extendable 6 and 10 footers by 5/8 or 3/4''. to this day i've never actually seen a 1.2m rod of any size and i've probably be responsible for putting more rods in the ground over the years (well over 400 on my present project alone) than anyone else here. ...lol!!

One last word, what would any of you rather have, a coupled stable 30 ohm rod or a 200 ohm unstable single rod?? It's a real no-brainer isn't it?? lol!!!

i`v said it before over various issues eng....if they cant see it in a book....some folk`s minds just seem to fall apart...lol....cant think on the spot.....i mean the obvious thing would be to get it as low as you can....but as the book says different..lolffs...

 

[Deleted member 9648]

One last word, what would any of you rather have, a coupled stable 30 ohm rod or a 200 ohm unstable single rod?? It's a real no-brainer isn't it?? lol!!!

But this assumes that anything approaching 200 ohms IS going to be unstable...the fact is it isnt....why should 200 ohms be any more unstable than 30 ohms?
As I've stated on here before I've tested and installed many 'useless twigs' in my area over many years and typically get readings of between 100 and 150 ohms summer and winter.Some have been on installs which have had regular updates and alterations over long periods and so have had regular Ra tests,if I have found dangerously unstable Ra readings believe me I would be doing something about it.....but I havent. And many of the "it's got to be 20-30 ohms" brigade seem to forget that 30 ohms or 200 ohms they are still totally reliant on an RCD to meet disconnection times
Of course if in your ground you cant get a stable Ra with a 'twig' then dont use one....but to state across the board that standard UK rods are never going to be adequate or stable is wrong.

 

[trev]

You well knew my opinions on Ra values when you stated anyone who thinks the Bs 7671 maximum value of Ra is ok is a fool.... Calling someone a fool is hardly a good starting point for a debate is it?
More than happy to be on your ignore list mate...but you aint on mine,I'm not that childish.

To be totally honest, I didn't know youre opinion on Ra values. It was not my intention to annoy you directly when I gave that comment.
My initial reaction was, with hindsight, an over reaction. Please accept my apology for that.
However I do maintain that an Ra of 200 ohm is neither stable nor acceptable for the reasons I have stated above even though there are occassions where that reading may be stable depending on soil conditions.
It is my personal preference to aim for an Ra in the low 10s of ohms and lower if I feel it achievable, further, I believe that we all should be striving for the same.