Termination of SWA on distant end of TT supply

[JohnW2]

I suppose that need is probably the wrong word to use there but I would definately remove it if I was doing the install.
It serves no purpose as has already been mentioned the OCPD at the origin of the SWA will provide ADS in the event of a fault, and all the RCD does is provide a remote point of failure in the event of a fault.
At least it's time delayed, so it shouldn't ever trip, but I'd still do away with it anyway.

Yes, I agree with all that, with just the one caveat that usually applies to removal of redundant RCDs - particularly given that it's time-delayed, and therefore shouldn't ever operate, in some situations it can be useful to retain it as a means of isolation.

Kind Regards, John.

 

[JohnW2]

The 3 rods provided the main earth, and the metallic grid was bonded to keep the concrete at the same potential as all the parlour metalwork and milking equipment.
I can't remember the exact figures, but connecting the bonding to the grid did lower the figure a bit to 2 ohms, so i suppose my Ze was actually a bit higher than 2Ω (But not a huge amount IIRC).

You may have missed a trick there! I think 542.2.1 would probably have allowed you to claim that the grid was a deliberate part of the earth electrode system, thereby keeping your Ze at 2Ω.

Kind Regards, John.

 

[RF Lighting]

No, it formed part of the supplementary equipotential bonding arrangement as per 705.415.2.1

 

[JohnW2]

No, it formed part of the supplementary equipotential bonding arrangement as per 705.415.2.1

I'm sure it did, but in terms of gaining tricks, as I said you could probably have claimed that it was a deliberate part of an earth electrode system, per 542.2.1

Kind Regards, John.

 

[RF Lighting]

I'd only be cheating my self......