eskimobob said:ScottM said:
Disclaimer: I am not a qualified sparkie.
I was told that generally speaking the exportation of a TN-C-S (earth neutral combined - separated) supply is the decision of the local distribution network operator (DNO) and only done with their permission. In the absence of such permission it would be recommended to use a TT system (i.e. local earth rod) and RCD protection. However apparently most DNO's will allow such exportation to an outbuilding provided it is 2 meters or less in distance from the main building.
If you read about it on the IET wiring regulations forums, there is considerable debate over the issue of exporting the earth from a TN-C system and different sparkies do different things. They each have to sign off the paperwork in the end and if they are prepared to do so then they will :?
Personally the idea that in the event of a supply neutral fault my shed could float at some potentially dangerous voltage is of concern and I would therefore prefer to provide the earth myself in the form of a good earth spike.
My friend (who some met at the hot break) is a senior electrical engineer for a large utility company. He tells me that with the number of instances of copper theft increasing, the "lost neutral" problem is more common than it was and has led to numerous house fires
Thanks for that, that would probably back up what I was told then
It may be something for me to "upgrade" in the future then. Would I be right in saying I could replace the outgoing cable with armoured 2 core then? And just have a separate earth to the consumer unit? The RCD will be in the house though.
I know what he means with the theft. I've heard of a few electrical "issues" due to the spikes being stolen. One was in a HUGE server storage location where the earth spike was stolen. I can't remember the exact details but I remember the damage being significant.
