Lead sheath SWA as earth

[robo83]

I attend a job today and can see the Main earth is via a tag to the SWA lead.

I called DNO and they informed me if the ze is within permitted Tn-s values (which it was 0.20 Ohm) then leave it in place. I requested a PME upgrade and they wasn't keen since this was in place.

Looking for some advice with this, is it permitted or do I convert to TT.

 

[Des 56]

I suspect if you were to show them a photo of that earth clamp on their lead sheath they may not be so quick to accept it is their earth facility
There again if they have said its Tns why argue the point

 

[MJPD29]

Looks like a typical tns install, the ze is well within highest limit so there is no need to change it at all. Maybe just upgrade the earth bar there to an enclosed esco

 

[Pete999]

I attend a job today and can see the Main earth is via a tag to the SWA lead.

I called DNO and they informed me if the ze is within permitted Tn-s values (which it was 0.20 Ohm) then leave it in place. I requested a PME upgrade and they wasn't keen since this was in place.

Looking for some advice with this, is it permitted or do I convert to TT.

View attachment 44026

SWA Lead??

 

[telectrix]

it's not SWA, it's PILS (orPILC for some). that'sacommon way of providing a TN-S earthing. the lead sheathed cable is buried direct and the lead sheath provides the earth. pity about the DIY BS951 clamp though.

 

[westward10]

I would not go touching that clamp either, big bang and molten lead spring to mind.

 

[westward10]

Problem is if you convert to TT the lead sheath is an exposed conductive part so you would have to leave the earthing conductor in place so this negates the TT.

 

[telectrix]

I would not go touching that clamp either, big bang and molten lead spring to mind.

you bloody prophet of doom, you. .

 

[ipf]

Looks like a typical tns install, the ze is well within highest limit so there is no need to change it at all. Maybe just upgrade the earth bar there to an enclosed esco

Typical....with that earth clamp?

 

[Marvo]

Yeah I wouldn't trust that type of clampon a lead sheath but I also wouldn't touch it either if the Ze is good. What size wire is it between the earth bar and the clamp?

 

[Pete999]

Yeah I wouldn't trust that type of clampon a lead sheath but I also wouldn't touch it either if the Ze is good. What size wire is it between the earth bar and the clamp?

Bit of 7/036 by the looks of it, or 4 mm2 for the kids.

 

[Marvo]

You could be right with your imperial size, it looks like solid green colour insulation so probably quite old. I was quietly wondering if it was sufficient CSA for the supply...?

 

[robo83]

Thanks for everyone's input.

Pete 999, duly noted. I am reading up on the history of PILS cable now, to further enhance my knowledge.

I am going to call the DNO back when at the job and see if I get another decision/PME upgrade. If Its the same I will note on cert explaining.

 

[robo83]

Bit of 7/036 by the looks of it, or 4 mm2 for the kids.

Yes, spot on