UK Black cable off supplier's incoming cable?

[impish15]

Hi,

Any suggestions what this black cable is coming off the supply's incoming cable? Its a TN-S system, I thought it could be the earth conductor but the cable is black not green/yellow, plus it looks much smaller than 10mm2 plus there is already an earthing conductor coming off the sheath going to the MET.

Any advice welcome
Dennis

 

[James]

Looks like it’s the original earth connection

later, someone has cut back the sheath and added a pipe clamp and their own earth connection
I would ask the dno to come visit because of a damaged earth and let them repair the cable where it has been cut back.

 

[impish15]

Cheers James, i have done just that. DNO coming out today at 14:00

 

[Dustydazzler]

As James said Looks like the black cable is the original connection point and then some house badger has butchered the sheath and added a pipe bonding clamp and some green yellow earth and possibly disconnected the original black earth at the board

 

[telectrix]

we didn't have green/yellow sleeving back in 1940. there was a war on, you know. it was black so that the German bombers crews could not see it and bomb your house.

 

[James]

As James said Looks like the black cable is the original connection point and then some house badger has butchered the sheath and added a pipe bonding clamp and some green yellow earth and possibly disconnected the original black earth at the board

A little bit of knowledge is a dangerous thing!

 

[Dustydazzler]

we didn't have green/yellow sleeving back in 1940. there was a war on, you know. it was black so that the German bombers crews could not see it and bomb your house.

There is a big council estate near me which has black 10mm for the main earth , I simply put it down to the builders using up old cable they had at the time

But the German bomber thing does make sense when you think about it

 

[James]

@impish15
Any update on this?
it’s nice for the rest of us to know what happened

 

[mainline]

@impish15
Any update on this?
it’s nice for the rest of us to know what happened

Update: It worked !!, the Germans didn't see it

 

[impish15]

Hi James,

Yes the DNO came out and updated the earthing conductor, removing the old black earthing conductor (think it was 6mm2) and the newer 10mm2 cable attached via the earthing clamp. For the sheath he just wrapped it up in electrical tape. Not sure if there is another material he should have used to wrap around instead but he said that's how it's done

 

[Mike Johnson]

Was it electrical tape or self amalgamating tape?

 

[impish15]

Was it electrical tape or self amalgamating tape?

I asked him at the time and he said it was electrical tape. Assuming he should have used self amalgamating tape?

 

[mainline]

I asked him at the time and he said it was electrical tape. Assuming he should have used self amalgamating tape?

Self amalgamating tape in high temperatures/high UV disintegrates very quickly

 

[Mike Johnson]

I will have to tell the amalgamating tape around the junction box to the alarm cable in my field to the barn that it should not have lasted twenty years, naught tape.

 

[DPG]

Self amalgamating tape in high temperatures/high UV disintegrates very quickly

I've never had an issue with it outside. And it's been used by thousands of satellite and aerial installers over the years.

 

[mainline]

I've never had an issue with it outside. And it's been used by thousands of satellite and aerial installers over the years.

There must be different types, the stuff I have used has crumbled.

I just did a quick search on the internet and found some say its ok and some say to cover it in pvc tape.

Self Amalgamating Tape 25mm x 10m – The DX Shop Limited

thedxshop.com

There are different types one being rubber and one being PIB whatever that is.


Self Amalgamating tape is typically made from EPR rubber, EPDM rubber, butyl rubber or PIB (polyisobutylene)

Like this stuff isn't UV resistant

Self-amalgamating Tapes – <BR>Low Voltage Rubber Tape HTAPE-POWER600 19x6.7 (711-00200)

711-00200

www.hellermanntyton.co.uk

 

[DPG]

There must be different types, the stuff I have used has crumbled.

I just did a quick search on the internet and found some say its ok and some say to cover it in pvc tape.

Self Amalgamating Tape 25mm x 10m – The DX Shop Limited

thedxshop.com

Must have been cheap stuff.

Never heard of covering it with pvc tape. The rubber layer formed should be sufficient.

 

[impish15]

Just did a Ze test with the newly installed earthing conductor and got 0 ohms!!!!!!!!

 

[mainline]

Just did a Ze test with the newly installed earthing conductor and got 0 ohms!!!!!!!!

Did you try nulling the leads

 

[impish15]

Did you try nulling the leads

Yes leads all nulled before testing

 

[mainline]

Yes leads all nulled before testing

Have you another mft to try or another set of leads

 

[impish15]

Have you another mft to try or another set of leads

Good shout. I’ll grab one from the other electrician I work with and test on Monday

 

[Jim_e_Jib]

I will have to tell the amalgamating tape around the junction box to the alarm cable in my field to the barn that it should not have lasted twenty years, naught tape.

You have a field and a barn? You kept that quiet.

What ever next - a former owner of property in mainland Europe?

 

[mainline]

Must have been cheap stuff.

This is the stuff that I've been using, I bought a dose of them a few years ago, I see that it was discontinued in 2019.

 

[mainline]

Good shout. I’ll grab one from the other electrician I work with and test on Monday

I wonder if you are using fluke, as there was something about double nulling causing problems.
Let us know how you got on.

 

[impish15]

I wonder if you are using fluke, as there was something about double nulling causing problems.
Let us know how you got on.

Interesting didn’t know about the double nulling issue. Yes using a fluke 1653. I’ll keep you updated next week once re-test done

 

[telectrix]

This is the stuff that I've been using, I bought a dose of them a few years ago, I see that it was discontinued in 2019.

been searching for S/A tape in Green/Yellow. can't find any anywhere.

 

[mainline]

Interesting didn’t know about the double nulling issue. Yes using a fluke 1653. I’ll keep you updated next week once re-test done

Do you have any news ?

 

[impish15]

Do you have any news ?

Hi apologies for the delay, I have only got around to re-doing the test yesterday as caught up between jobs. I used my colleague’s tester and got 0.10 then I re-tried my Fluke considering the possible double nulling when I did the test previously and got 0.11 so looks like I might have double nulled when I did the test before. Thanks for the heads up on that

 

[davesparks]

I asked him at the time and he said it was electrical tape. Assuming he should have used self amalgamating tape?

It doesn't matter, it doesn't need any tape at all.
The lead sheath is fine to be left exposed, the extra layers on top were there for extra protection underground or in harsh environments.