- Reaction score
- 5,607
Evening all..
I have just been to a clients house to quote for some work and when checking the Main bonding I noticed that it just had a 10mm attached to the gas pipe and then straight into a separate earth rod, it was the same for the water (had it's own earth rod).
I realise that this would not be acceptable on a TNCS or TNS system as there could be a difference in potential between the earth formed by the earth rod and the earth of the TNCS or TNS. However this house is a TT. I believe it still needs to be bonded as usual, i.e 10mm back to the CU but I would be interested to know if I am right?
I believe I am right as under fault conditions where an exposed conductive part becomes live, all extraneous conductive parts (if connected to CPC in CU) should rise to the same potential. I cant see how the extraneous in this clients house will rise to the same potential under fault conditions as the only link between the extraneous and Main earth rod will be the general mass of the earth not a 10mm conductor?
Cheers.
View attachment 35588
I have just been to a clients house to quote for some work and when checking the Main bonding I noticed that it just had a 10mm attached to the gas pipe and then straight into a separate earth rod, it was the same for the water (had it's own earth rod).
I realise that this would not be acceptable on a TNCS or TNS system as there could be a difference in potential between the earth formed by the earth rod and the earth of the TNCS or TNS. However this house is a TT. I believe it still needs to be bonded as usual, i.e 10mm back to the CU but I would be interested to know if I am right?
I believe I am right as under fault conditions where an exposed conductive part becomes live, all extraneous conductive parts (if connected to CPC in CU) should rise to the same potential. I cant see how the extraneous in this clients house will rise to the same potential under fault conditions as the only link between the extraneous and Main earth rod will be the general mass of the earth not a 10mm conductor?
Cheers.
View attachment 35588