no earth

[sima24]

Hi, been to look at a rewire today and no earth connection at all. Tried to contact supply company to enquire weather the property is connected to a pme system but no joy after holding most the afternoon. I presume supply company doesnt have to supply an earth but just wondering if they would upgrade to pme or not? Or possibly it is a pme system but earth has been disconnected at some point (no sign of pme label tho) any views appreciated. Thanks.

 

[ackbarthestar]

is that digging it up then...to see how far it goes or is wrapped etc?

Lol, not across the misses flowerbed !

 

[ackbarthestar]

You've lost me there?? I must be missing something!! lol!!

But i'm off to bed now, i'm actually feeling sleepy tonight. ...lol!!

What, homework ?
Its the stuff you do at home !

 

[GLENNSPARK]

Lol, not across the misses flowerbed !

dig the garden then

 

[ackbarthestar]

dig the garden then

Its going to down about metre so unless you're putting in the foundations for an extension then its unlikely to be affected. A loop measurement or better still, run your test electrodes across the lawn and into the next doors garden to get a resistance would be sufficient.

Alternatively use the exploration hole to wack in a 'twigg' and back fill with bentonite - Job done - lol

 

[Geordie Spark]

Where can I buy some lead pipe, please?

PM Tidyboiler ..... she's got a few bits stashed in her handbag. :sailor:

 

[Geordie Spark]

pikeys

We have one of those somewhere on here.

 

[tidyboiler]

We have one of those somewhere on here.

:sifone:

 

[Geordie Spark]

:sifone:

............and as if by magic ......

Hello pet

 

[Stroppy]

I do realise that the services are not there to be used as an earth, and the difference between earthing and bonding, which is why I started all this: testing the effectiveness of my earth twig. I will see if I can get PME'd, which would be the better option, otherwise I'll get some chunky rods and start driving them into the mud-bath that is my garden.

One day I'll get under the floor and individually test all the pipework and find which one is the culprit, but for now I CBA!

Regular viewers may remember this discussion about my pitiful 125 ohm reading from my earth rod (and unbelievably low Ze through the bonding). I know it is nice to have follow-up on discussions, so let's put this one to bed:

This afternoon I finished work at lunchtime and as, for once, it is not raining I thought I would sort out my earthing before I got cleaned up for the weekend. I have now pulled out my old 'twig' and pounded in two of Sarnia Electrical's finest shiny 3/8" earth rods and connected up my earthing conductor. Now I have a much more reasonable Ze of 44 ohms and a fault current of a whopping 5 amps.

That will do! As my late wife said, deeper is definitely better.

 

[telectrix]

how deep have you gone?

 

[Stroppy]

Two rods screwed together, so 8 feet.

 

[Geordie Spark]

how deep have you gone?

All the way to my bow locks.

 

[Engineer54]

Two rods screwed together, so 8 feet.

They weren't 3/8'' rods then, if you were able to couple them together!! The 3/8'' things, are the twigs that you can't couple!! lol!!

Go back and test that new rod installation in 6 months time, you'll see almost certainly see an improvement on the present 44 ohms, ..and it will continue to improve for the next 18 months or so, as the soil slowly compacts tightly around the rods....

 

[ackbarthestar]

Exactly, I told you that 'twig's were the way to go.

Wack a 1.2m 'twig' in and the the Ra will decrease because of the contact resistance around the electrode.

Better still, back fill with conducting cement and you've increased the contact resistance immediately.

As an aside, it only works when the soil conditions are right and Hong Kong, Gibraltar and most of Norway plus the Himalayas and a couple of places just outside our local pub are not the best places for any 'twig'

 

[Engineer54]

Exactly, I told you that 'twig's were the way to go.

Wack a 1.2m 'twig' in and the the Ra will decrease because of the contact resistance around the electrode.

Better still, back fill with conducting cement and you've increased the contact resistance immediately.

As an aside, it only works when the soil conditions are right and Hong Kong, Gibraltar and most of Norway plus the Himalayas and a couple of places just outside our local pub are not the best places for any 'twig'

You can sum that up very easily, where twigs are concerned No-where will twigs be any good!!

I wouldn't say Hong Kong is a particularly bad area for creating a TT system, far from it in fact, depends where your trying to create the system. Remember Hong Kong isn't just the Island(s), it also incorporates a section of the mainland too!! lol!!

The earthing on both the Stations and the tunnel overhead rail system, as a whole, was impeccable on the MTR (Mass Transit Railway). I know because i was responsible for large sections of it, along with various much needed CP systems to suit!! ..lol!!

 

[Stroppy]

Oops my mistake, they are 5/8" not 3/8". These mediaeval measurements confuse me! 10 or 15mm make more sense to me. (see: What we SHOULD have been taught in our senior year of high school - The Oatmeal )

I will try to remember to retest in a few months time, as hopefully the soil around the top rod will have settled a bit. At the moment with all the movement from driving it in it is flapping like a dick in a shirtsleeve.

As an aside, it only works when the soil conditions are right and ...a couple of places just outside our local pub are not the best places for any 'twig'

Oh I don't know, all the wee would keep the soil nice and moist! Although may corrode the rod quite quickly.

 

[ackbarthestar]

I will concede that you are referring to a fully integrated system over several miles - hardly 'twig' territory.

The basic two up two down domestic installation with a 'twig' would suffice, IMO, as long as you get a reasonable Ra of less than about 50 Ohms and as you say this value is likely to decrease as the electrode beds in.

In any case, unless you can get the value of Ra below 1 Ohm you'll need supplementary protection Earth fault protection from RCDs

 

[ackbarthestar]

Oops my mistake, they are 5/8" not 3/8". These mediaeval measurements confuse me! 10 or 15mm make more sense to me. (see: What we SHOULD have been taught in our senior year of high school - The Oatmeal )

I will try to remember to retest in a few months time, as hopefully the soil around the top rod will have settled a bit. At the moment with all the movement from driving it in it is flapping like a dick in a shirtsleeve.


Oh I don't know, all the wee would keep the soil nice and moist! Although may corrode the rod quite quickly.

Backfilled with rubble with an overlay of concrete and tarmac ? You'd probably need a 10m RSJ pile driven into the ground

 

[Engineer54]

I will concede that you are referring to a fully integrated system over several miles - hardly 'twig' territory.

The basic two up two down domestic installation with a 'twig' would suffice, IMO, as long as you get a reasonable Ra of less than about 50 Ohms and as you say this value is likely to decrease as the electrode beds in.

In any case, unless you can get the value of Ra below 1 Ohm you'll need supplementary protection Earth fault protection from RCDs

Well for a start i wasn't referring to twigs in my assessment of Hong Kong, just that it isn't a particularly ALL bad area to create TT systems. I don't think i've ever seen a 2 up, 2 down residence in Hong Kong, they are all high/medium rise apartment blocks, or massive residence's of the very rich!! lol!!

Nope, ...it wouldn't, for a kick off there is no-way that a twig will offer any form of a stable TT system to an installation.

Twig electrodes are no good to man or beast, they are little more than the size and thickness of test spikes used for testing Real electrode rods... lol!! I've actually never seen one either, and certainly not in any of the countries i've worked in. Say's a lot for the UK, when you think about it!! lol

 

[Engineer54]

Oops my mistake, they are 5/8" not 3/8".

I will try to remember to retest in a few months time, as hopefully the soil around the top rod will have settled a bit. At the moment with all the movement from driving it in it is flapping like a dick in a shirtsleeve.

That's why most electricians that do a lot of TT installations use a SDS with either a shop made or home made driving head, to drive rods into the ground, ....and in a fraction of the time it probably took you. ...lol! It also considerably reduces the flapping about of the rod during installation, that you get when using a club hammer or the like!!