TNCS Outbuilding earthing arrangement

[pencilpusher]

I have exported the equipotential zone to outbuildings before with no problems and mostly without having to bond any extraneous parts, because there have been none. Nice low ZS readings. No problem. (unless "Rodman" sees this! He thinks it is a big no no for some reason)

 

[Moses]

I have exported the equipotential zone to outbuildings before with no problems and mostly without having to bond any extraneous parts, because there have been none. Nice low ZS readings. No problem. (unless "Rodman" sees this! He thinks it is a big no no for some reason)

read post#2

 

[pencilpusher]

I have read all the posts! What about the house TNCS then? The world is all if's and but's!

 

[Moses]

I have read all the posts! What about the house TNCS then? The world is all if's and but's!

run a 2 core SWA to the hut, an RCd cu in the hut with TT supply from the SWA, and an earth rod at the hut end. SWA earthed at the supply end but the SWA earth insulated at the load end.

 

[pencilpusher]

^^^^^^^ What about the TNCS in a dwelling with no outside hut?

 

[rich.250]

Where do all these rumours come from.........?
Its all written in black and white (with green covers)
Exporting TNCS or PME is fine!! along as any extraneous conductive part is connected to the MET.
How many times have i heard the you can't do this rumours only to look in the regs to prove them wrong haha

 

[pencilpusher]

I have seen this on here many times. There seems to be an obsession about exporting the equipotential zone in outbuildings. Nothing wrong with it and its fine according to the Regs. Period.

 

[rich.250]

I can see there point about loosing the neutral.... as I've seen it a few times!!
But if it was that much of a concern TNCS supplies would be banned and it shouldn't occur with PME

 

[pencilpusher]

Here is the main thread about this very subject previously. Same old rumours.

http://www.electriciansforums.net/e...me-outbuildings.html?highlight=exporting+tncs

 

[Moses]

I have seen this on here many times. There seems to be an obsession about exporting the equipotential zone in outbuildings. Nothing wrong with it and its fine according to the Regs. Period.

In that case you need to ensure that you Zdb at the hut complies with the max for the earthing system that you are exporting.

are you going to calculate the distribution cable R1+R2, and hence calculate the Zdb, as well as the cable size for the expected load? not many do.

or as most people, just design for the expected load and then install the cable, and then take the Zdb measurement afterwards? and hope that it is within the regs?