TN-S supply 4.2ohms, this is the solution from the DNO!

[GaryM]

I recorded a Ze on a TN-S supply as 4.2ohms. Consumer unit is an all insulation Wylex twin RCD unit.
I spoke to the landlord of the property which was currently empty (now occupied) and told him he needs to contact the DNO with regards to the high Ze.

They came to site and this was the result! Essentially it looks like they're treating the high Ze with an RCD though all circuits are protected by 30mA RCD's.
I've asked the landlord to contact them and ask, in writing, for their reasoning behind what they've done and when they're going to return to maintain the earth that they're responsible for.
Also why we couldn't get away with leaving an enclosure flapping in the wind, two circular conductors through a single stuffing gland designed for one conductor. They seem to be a law unto themselves.

 

[Richard]

Outstanding!

 

[Strima]

That just fills me with confidence...

 

[D80]

Are they intending to return to this or is it left as a finished job?

 

[GaryM]

Are they intending to return to this or is it left as a finished job?

I've asked the landlord to get a response to that in writing and also their reasoning.

 

[PC Electrics]

Surely the simplest thing they could have done would be turn it into a TN-C-S??

 

[Sparkystu79]

Is there any seals on that enclosure? If not i'm sure a knowledgeable tenant could be helping themselves to some free electricity!

 

[GaryM]

Surely the simplest thing they could have done would be turn it into a TN-C-S??

Possibly not as the PEN conductor would have to be earthed at multiple points to reduce the risk of a broken neutral.
There would be more to it that just linking out in the service head.

 

[GaryM]

Is there any seals on that enclosure? If not i'm sure a knowledgeable tenant could be helping themselves to some free electricity!

No seals at all, nor is there on the meter or the main fuse.

 

[tony mc]

I would imagine this is a short term fix until they resolve the high ZE.

Makes you wonder.

I have a friend in the DNO and I cant see him leaving it hanging like that it would of been secured to the wall and sealed with it being left looking professional!

I put money on that its repaired before you get anything back in writing!

 

[GaryM]

I put money on that its repaired before you get anything back in writing!

That's where my money is too, hopefully with the perpetrator getting a rollocking in the process!
Still pointless as it's offering no added protection as the consumer unit is a twin 30mA RCD unit.

 

[tony mc]

I would think they are covering the high ZE with the 1667 on the supply side regardless of what the customer has IMO!

 

[J&M Electrical]

Is it just me or is that system in the picture a TNCS? Or is it a 3wire Supply?

 

[GaryM]

No, it's a TN-S.
The earth is split from the sheath inside the cutout. There's no N-E link in place internally.

 

[Marvo]

Speechless.

Even if that's a temporary fix it's atrocious. It was probably overall safer before they touched it.

 

[Mark.W]

It would be safer just to spike it IMO!

 

[ezzzekiel]

bit surprised they would leave that even as temp measure

 

[GaryM]

It would be safer just to spike it IMO!

I looked specifically for am earth rod as that's what I expected when the landlord explained that they had fitted an RCD in line with the tails but no, not there.

 

[GaryM]

bit surprised they would leave that even as temp measure

Me too, totally shocked when I saw it!

 

[rich.250]

Good job DNO!! (insert sarcasm here)

So they can fit rcds now??
And then you have to in series so the dual Rcd board is pointless.....
Lol