How to get a TT system upgraded to TNC-S

[Paul P]

Hi

I have just rewired a mate’s house with his help and the existing earthling is TT on overheads. We have tried to get it changed to PME (TNC-S) but who do you contact now a days. Back when I did nothing but house bashing in was a piece of cake, now its been split up they keep sending bods who check the Ze and say no I don’t connect tails into a meter.

Bonding etc is to current PME requirements, I just need the earth connection done.

 

[Paul P]

No thoughts about actually improving the system then??...

Improving? in what way. House has been rewired duel RCD board fitted with RCBO's to smokes and fridge circuits. What more do you want if you cant get PME.

 

[Engineer54]

Improving? in what way. House has been rewired duel RCD board fitted with RCBO's to smokes and fridge circuits. What more do you want if you cant get PME.

You have never mentioned as far as i can see, the value of this single rod?? Is it good or bad?? If it's bad, then there is always room for improving the value, come to that even if it's a pretty good value it can be improved.
Better i think, than that old chestnut of totally relying on a RCD device!!

 

[Paul P]

The value of the rod is less than 100 ohms, i believe that is what the regs require. I could improve the value like they do in Australia but it is not permitted in the uk.

 

[Engineer54]

The value of the rod is less than 100 ohms, i believe that is what the regs require. I could improve the value like they do in Australia but it is not permitted in the uk.

So what is not permitted then ??

 

[pennywise]

Pishing on it probably

 

[somersetsparks]

I always try to get rod readings below 10 ohms, although it is not always possible, Even if you put anorthe 2 rods in I imagine you could get it down quite a bit, and would probably only take an hour.

 

[Engineer54]

Good to hear mate. Always better to extend a good rod deeper, before adding rods to the system, but a lot depends on the ground soil your having to deal with...

 

[pennywise]

I always look for the most fertile area, quite a good indicator of getting a good reading.

 

[somersetsparks]

Good to hear mate. Always better to extend a good rod deeper, before adding rods to the system, but a lot depends on the ground soil your having to deal with...

Yeah when I was doing a bit of farm work I would regularfily see readings of about 1 ohm with bonding connected due to the amount of steel stuck into the ground!

 

[Paul P]

So what is the fasination of a silly low Ze on a stake?