TT Earthing question

[steveg]

I have just replaced a lighting circuit. The earthing for the house is TT, when testing the Ze I have a reading of 299 ohms, but when measuring the Zs the reading is 27 ohms. I must have a secondary earth through the incoming water pipe.

Please advise how can I get a earth pin to get a reading of less than 27 ohms so that the incoming pipework is not the earth path?

 

[steptoe]

Doubtful if its possible in this situation.

Its not a problem, try another rod to get your Ra under 200 if you can.

 

[m4tty]

I have just replaced a lighting circuit. The earthing for the house is TT, when testing the Ze I have a reading of 299 ohms, but when measuring the Zs the reading is 27 ohms. I must have a secondary earth through the incoming water pipe.Please advise how can I get a earth pin to get a reading of less than 27 ohms so that the incoming pipework is not the earth path?

Not a problem mate. I done one where Ra was 29 ohms (good for a rod) and when i done Zs for lighting circuit it was 0.29 ohms. So the fault path must have been through next doors TNS lol. Id still try and bring your Ra down to 200 ohms if poss mate

 

[ADS]

Has he tested Ra?

 

[steveg]

Thank you for the advise. Installed new earth pin and reading is 110 so that should be ok.