Rcd tripping problem

[Braz1845]

Hi guys here's an update'ive been on site today and done a thorough inspection and found that IR between earth and disconnected neutrals all fine(2 circuits 22 Meg all the others 299

One thing that has come to light is that the over head line has recently been changed to pme or pmb,not sure which .
But the overhead line now has a earth cable running from what I believe to be neutral to an earth electrode,which is about 30 yards from my incomer
Ive checked linked N & E at my supply and all ok,wondered if I was getting some sort of leakage to the suppliers neutral which is connected to an earth electrode in close proximity.
finally the property used to be a TT system and electrode still in the ground but not connected,also water supply in lead I think
oh and I've changed the Proteus RCDS for Hager
So wait and see!!!!!!!!!

 

[Engineer54]

No the overhead supplies PME N-E connection will have no affect on your RCD tripping problem. Depending on the Ra of the existing rod it might be a good idea to reconnect the rod to the MET. Don't bother if the Ra is way over 10 ohms.

22 Meg ohms equates to 22 million ohms, so you don't have a problem there either. So if the problem remains you have more checking and testing to do!!