TT earthing on a rewire | on ElectriciansForums

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J.C.E

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Evening men!

Looked at a upcoming rewire
it is for a mid terrace old house.

A single phase comes into the house next door- one 60a head in next doors house >>meter>>cu
Then a 2nd feed goes into the house I am planning to rewire into a 60a head>>meter>>cu

I have seen this before- but what concerns me is the earthing
it is just a bonding clamp around the incoming servive- then into a met in each house
so a TNS

however upton getting a quick ze reading it was 4.3ohms- likely to be loose clamp

The builder got UKPN out and they said this to him:

"Single supply to no17 with a link to no 15 through the wall as we knew.

When Installed by London Electricity Board 50 or so years ago no earth was provided. UKPN having adopted the network will not and do not provide an earth where it is not present such as on a TT supply like this one.

The earth next door is not fitted or owned by UKPN (nor is the link between 15 and 17 oddly but they do own the head in 15...) If the steel pipe that covers the lead insulation of the supply underneath is in good contact and the pipe is very clean of rust under the earth bonding it could be a good earth. If its not it wont be.

2 options.

1- New Supply - PME.

2 - Earth Spike"

the client can not afford a new PME supply

If I go down the route of install a rod and making it a 'offical' TT system do I need a upfront RCD

they want the c/u remote from the meter so it will go meter >> sw isolator>> cu via 3c SWA
the consumer unit will be dual 30ma rcd

do I need a upfront 100ma rcd to cover the SWA sub main or am I over thinking again!
 
Buy a Lewden switch fuse and change the main switch for an 100mA time delayed RCD.

[ElectriciansForums.net] TT earthing on a rewire


[ElectriciansForums.net] TT earthing on a rewire
 
would you guys feel inclined to leave the 16mm connected to the clamp around the incoming next door- as this is giving me 4.3ohms as well as the rods

would struggle to get that with a few rods??
 

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