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Chat Area => General Discussion Area => Topic started by: tigers_gonads on 16 July 2012, 21:29:15

Title: Who are the sparkys on here (other then me) earthing question
Post by: tigers_gonads on 16 July 2012, 21:29:15
As of 17th edition, what is the rule ref main earths from consumer unit ?
Board is twin rcd 17th edition certified.

No incoming mains earth cut off point so looking at useing a earth spike and 16mm cable.

What is the minimum depth that the spike needs to be banged into the ground ?
Is the max length of the mains tails (25mm) and the mains earth (16mm) still 3 meters  before I have to pish about with split concentric  :'(

TIA
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: Martian on 17 July 2012, 08:33:45
What is the minimum depth that the spike needs to be banged into the ground ?
That all depends on the surrounding soil and a couple of other variables, but 3 meters is what you need to aim for.

Is the max length of the mains tails (25mm) and the mains earth (16mm) still 3 meters  before I have to pish about with split concentric
That is the generally accepted length, but the DNO may allow you to run them further.
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: albitz on 17 July 2012, 09:41:24
Thats just what I was going to say. :y







 :D ;D ;D
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: tigers_gonads on 17 July 2012, 09:51:45
What is the minimum depth that the spike needs to be banged into the ground ?
That all depends on the surrounding soil and a couple of other variables, but 3 meters is what you need to aim for.

Is the max length of the mains tails (25mm) and the mains earth (16mm) still 3 meters  before I have to pish about with split concentric
That is the generally accepted length, but the DNO may allow you to run them further.


Thanks for that  :y

Earth spike is a 4ft b&q special so unless somebody pulls it out to measure it  :-X :-X :-X ;D

Just need a plasterer that can do actual plastering and turn up when he says then hopefully (oneday) the gas man will turn up (waiting 8 weeks now) and run us a new gas pipe so i'll have a meter to connect upto  :D :D
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: Kevin Wood on 17 July 2012, 11:00:04
Earth spike is a 4ft b&q special so unless somebody pulls it out to measure it  :-X :-X :-X ;D

Or measures the fault loop impedance.. ;)
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: tigers_gonads on 17 July 2012, 11:04:18
Earth spike is a 4ft b&q special so unless somebody pulls it out to measure it  :-X :-X :-X ;D

Or measures the fault loop impedance.. ;)


Yeh, thats what is bugging me  :(

The ground is very wet at the moment so (fingers crossed) it should pass  :y

If not, the landlord with have to get his hand in his pocket and pay the local supplier too put a cutout in  :(

I know one thing, its not coming out of my money
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: freecall666 on 17 July 2012, 11:07:26
when they removed our old earth spike, it was 9 foot long, as we on mains earth now, and all under ground.
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: tigers_gonads on 17 July 2012, 11:12:29
when they removed our old earth spike, it was 9 foot long, as we on mains earth now, and all under ground.

You used to be able to crimp the end of the cable and clamp it to the incoming mains metal caseing but iirc, thats now a no no  :(
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: Martian on 18 July 2012, 05:23:02
Earth spike is a 4ft b&q special so unless somebody pulls it out to measure it  :-X :-X :-X ;D
That is just less than half the length required by law.

You used to be able to crimp the end of the cable and clamp it to the incoming mains metal caseing but iirc, thats now a no no  :(
You can still do that if that is how the original earth is supplied, is the meter labelled up as a PME system?

As Kevin has also pointed out (and I'm sure I don't need to tell you), you can end up creating a whole host of other issues if it isn't a PME setup to start with.
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: tigers_gonads on 18 July 2012, 05:44:32
Earth spike is a 4ft b&q special so unless somebody pulls it out to measure it  :-X :-X :-X ;D
That is just less than half the length required by law.

You used to be able to crimp the end of the cable and clamp it to the incoming mains metal caseing but iirc, thats now a no no  :(
You can still do that if that is how the original earth is supplied, is the meter labelled up as a PME system?

As Kevin has also pointed out (and I'm sure I don't need to tell you), you can end up creating a whole host of other issues if it isn't a PME setup to start with.



Yeh, it looks like its a standard PME setup to me  :y

I've had the 16mm earth conected to the incoming caseing for the past 6 weeks with no problems.

The press to test button on both RCD's trip instantly so I can't see any problems with it tbh.

Thanks for the advise lads, I didn't realise how rusty I was becoming until i've had to start using my brain cells again  :-[ ;D

Powered up all 7 circuits and the new alarm system yesterday with no problems so I must have done something right  ;D ;D

Its knackering but its good to get my hands dirty again.

Just sick and tired of waiting for other trades now  >:(
 
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: Martian on 18 July 2012, 06:29:07
Thanks for the advise lads, I didn't realise how rusty I was becoming until i've had to start using my brain cells again  :-[ ;D
You ain't the only one who is a bit rusty, I had to get the book out yesterday to double check what I was posting was factually correct  :-[

Just sick and tired of waiting for other trades now  >:(
The other trades always hold us up, which is why I think it is wholly right & correct that they find a live cable every now & again  ;D ;D
Title: Re: Who are the sparkys on here (other then me) earthing question
Post by: Kevin Wood on 18 July 2012, 09:51:19
The press to test button on both RCD's trip instantly so I can't see any problems with it tbh.

It goes without saying, of course, that that only tests the RCD internally and that you should still ensure a decent earth is provided.  ;)