Replacing VOELCB

[Engineer54]

That's totally up to you Sparc, but nothing in writing, and a few years down the line when something goes wrong, be it of what you have done or not, the fingers going to be pointing at you. Do you honestly think a so-called responsible DNO Engineer is going to own up to giving you permission to alter DNO equipment?? Not on your Nelly will he!!!

 

[sparc]

This is second situation in as many weeks in which the supply is being moved around the building site and the DNO(s) are messing the customer around. This is another configuration that's going to get demolished in next few weeks, and a new supply head, meter and earth are going to get installed in what will be a newly built part of the house. So I see my responsibility here as being making the customer as safe as possible in this transition period. He's getting no help from the DNO on that. When I got there today to look at this PME the customer admitted the electrode had been dug up by the builders, and was sitting on the ground - my 22.8 Ohms reading probably reflected the fact that it's been p******g down for over 24 hours here, and site is a marsh.

All that aside... it's this VOELCB that's got me thinking. If the trip function doesn't work without separate external earth reference (my understanding of a VO-ELCB). So was the configuration safer as a TT system with a working VOELCB, or now as a TN-C-S without one - but with a nice low Zs value? I've still got the option of putting in a 100mA type S RCD, got a standalone here on my desk.

 

[Engineer54]

Your far better off with a PME supply than a low value unstable TT system. Nothing to stop you driving in a rod and connecting that to MET, in fact it's good practice to do so!! But not much point if it's just going to be a 200 ohm short twig like spike!!!

Very few of those old VOELCB ever worked correctly from the day they were installed... lol!!!

 

[sparc]

I think I'll put the 100mA S RCD in place of that VOELCB - even at my own expense. Better than sleepless nights! :-0

 

[sparc]

Just to close the loop on this, I did email the DNO noting down everything from the various phone calls on this subject. Got a receipt response back, showing it had been received, but no answer back ....