Main bonding made to separate earth rod?

[HappyHippyDad]

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

 

[PEG]

Hi bud,who installed the rod,if it actually is,it does not look very old.

 

[HappyHippyDad]

No idea chap, it's the first time I've seen this client!

 

[westward10]

I'd say that has been there a while the red and white label on the conduit box is bleached white. It is a bit odd but yes it should be connected to the MET assuming there isn't a conductor snaking around underground joining them all together.

 

[HappyHippyDad]

I'd say that has been there a while the red and white label on the conduit box is bleached white. It is a bit odd but yes it should be connected to the MET assuming there isn't a conductor snaking around underground joining them all together.

I didn't take the covers off Westward so hopefully they'll be connected but probably not!

 

[Wilko]

Evening all..

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?

Hi HHD, the rod is the means of earthing for the installation and needs individual connection to the MET, where the protective bonding conductors can also join the party
Re the pic - I've never seen this done before - diy?

Edit - Westie outdrew me - oops

 

[The Ghost]

Assuming there is no other rod that arrangement means there is no earth for the installation.Have you looked at the MET, what is going into it?

 

[HappyHippyDad]

Assuming there is no other rod that arrangement means there is no earth for the installation.Have you looked at the MET, what is going into it?

The house has 3 earth rods.
One earth rod is attached to the CU, the other 2 are used solely for the gas and water as seen in the picture.

 

[Midwest]

I don't think using an earth rod to bond metal services, is in the spirit of reg 411.3.1.2 ?

 

[DPG]

Couple all the rods together and re wire them and the bonds to the met.

 

[The Ghost]

The house has 3 earth rods

Ok so there is an earth electrode to MET. Agree with @DPG