Earth Connection Upgrade?

[DaveSz]

Hi All,

Could anyone please tell me what to make of this (See uploaded Picture). Just had, what I thought was a conversion from a TN-S to TNC-S earthing. Or have I now got a combination of both.

When I got home after having the suppliers electrical subcontractor complete the work while away at work myself. I left a note to inform him of concerns about the size of the supply tails from the meter to the D.P. Isolator switch. The neural appears to be of a lower size than the Line conductor, which I am 99.9% sure is 16mm.

The work cost £31 to do. Would I have to call them out again at added cost to replace the tails from the meter to the isolator.

If I am to have the consumer unit replaced with a 17th edition compliant unit. Don't the tails have to be both 25mm.

Previous albub shows the system before conversion

Any advice much appreciated.

 

[Steve]

Untitled

• DaveSz
• 26 Jan 2009
• 1

Your other 2 photos were too small to bother with.

 

[Taylortwocities]

PS I heard that MK have stopped making albubs, but you can still get them on eBay.

 

[DaveSz]

Ok. old photo not good but what do you make of the latest

 

[Taylortwocities]

It looks like, well, its hard to say really.

I just can't seem to focus on it properly......

 

[Steve]

It looks like a combo of TNS and TNC-S.

 

[Pensdown]

I would say it's TNC-S with the armour bonded?

 

[Spark123]

TN-CS gets my vote too. Only people to tell you for certain tho are the DNO.

 

[Pensdown]

Because you now have two very good fault paths, I would get your sparks to measure the new Ze & PSCC to make sure the fault currents are under the maximum for your protective devises.

 

[Spark123]

Just looking at what is connected to the top block, possibity that the CPC between the main earthing terminal and the CU is undersize.

 

[securespark]

Don't hold me to this, but IIRC, from memory, that cut-out does not have an NE link option, so I would hazard a guess it is TN-S. But who knows what the DNO have done. Only they will know!

 

[RF Lighting]

It's PME with the armour bonded as pensdown said.

Not entirely sure why they have sealed the consumers MET

I can't size tails from a photo.

I'm loving the SqD main switch in a wylex box

 

[sm1thson]

if its a new PME then there should be a sticker to say, its likely that warning sticker on the cutout does say its PME.

If its PME then it is TNC-S. or to quote the wiki "In order for the Electricity Board to provide a TN-C-S supply, they have to construct their network to the standards of PME (protective multiple earthing), this is why a TN-C-S system is often referred to as a PME installation."

 

[RF Lighting]

If you squint carefully, you can just about make the label stuck on the bottom of the cutout.

It says something along the lines of

Untitled

• RF Lighting
• 27 Jan 2009
• 1

 

[Steve]

Mine says YEB, cos its REALLY old