Sine - Shoot me down in flames please if i am wrong or have got the wrong end of the erm... cable at some point but to truly export pme would you have to spike the n at income point to the outbuilding to extrmley low and reliable z?? I know this is not to be done just a question
Your not really 'exporting' anything, your just continuing your own supply outside the equipotential zone, which in reality aint a big deal due to the 'stake down Rod'.
a) the earth rod would serve no purpose if the remote building was had the normal main and sup bonding within it? b) If it was say a building with exposed metal work on the exterior , then the earth rod would cancell out any differences in voltage betwwen the pme earth and the earth you're standing on ? c) But that would only happen if you were standing in the vicinity of the earth rod , on the other side of building away from the earth rod the differences would occur ? d) But,but any domestic property with a pme supply could be in exactly the same situation as an outbuilding , there could also be differences between the buildings pme earthed structure and the true earth ouside ?
most people dont double up the earth with a 3 core to get better z though i dont think do they. Most... no But it is a trick thats used by the cunning when thy know at the design stage that there will be an issue... and its a a very valid trick indeed
Existing PME/TNS supply at service position. Sine, that,s the key line! Even if you, install the 10mm, to your,e rod, you are still at a tns/pme/ supply at the out-building! IF, you isolate, the cpc, from the incoming supply, totally, hence you are now, classed, and only now, as a true TT supply! You, gain zilch, by doing your,e method!
Sine, some of them, have logged it! Have, the balls to say bxxxxxx! I, had to do it! NOT, a crime! WE, all make mistakes! But, sorry, wrong!
Sine , on a pme system up to how far from a property might the supply run before it is spiked to earth ?
Might be missing somefink but...... If you export PME then you would if outbuilding had gas/water pipes, so why the rod? its only for extra safety? & the gas/water pipe will act as a bl** good rod anyway! Ant
So you have Captain Sir , I am undecided ,I think . However I really would like to know how far a pme supply cable might run before it is spiked to earth .
1200mm copper rod near the service head, sir? - The Ultimate PEN/IS Extension ?? Leave me out of it..
The PME is not bein exported - the 3rd core is a combined CPC and equipotential bonding conductor. Making the earth (3rd core) the same size as the neutral 10mm satisfies the regs for a main bonding conductor for PME plus other earthing systems - 547-02-01 Armour is bonded as extraneous conductive part Earth spike is not actually required but is a belt + braces option in the event of a fault...
. Talk Search Talk Sign In Read/Post Messages My Talk Details What I'm Watching Talk FAQs Terms & Conditions Home » Talk Screwfix » Electricians' Talk Topic: The Ultimate PME/TNS Exportation! Replies: 52 Pages: 4 Last Post: Mar 25, 2007 10:09 PM by: sparkin! Reply to this Topic Search Forum Watch this Topic Back to Topic List Topics: [ Previous | Next ] Replies: 52 Pages: 4 [ 1 2 3 4 | Next ] sinewave Posts: 8,000 Registered: Jan 16, 2005 The Ultimate PME/TNS Exportation! Posted: Mar 25, 2007 9:48 AM Reply Existing PME/TNS supply at service position. Run a minimum of 10mm 3 core SWA cable to your external location, following all approved cable installation procedures. Terminate in to a Metal Clad Dis-Brd. Link SWA Earthing Tag to DB-1's MET with 4mm, despite it being a Metal Clad Dis-Brd. (Belts & Braces!) Drop an Earth Rod in as close as possible to DB-1 and connect back to DB-1's MET with 10mm Bond any metal services entering the remote building with 10mm Bond any exposed metal framework of the building with 10mm Resultant installation has an excellent Ze DB-1 Resultant installation is tied down to 'True Earth' at it's remote location thus avoiding any 'potential' problems! Resultant installation avoids the need for expensive Time delayed RCD Split Boards! Comments and critisim gartefully received! ********!
Consider a pme supply entering a property, two conductors in the supply cable ,Live and Neutral which also doubles as Earth. What is the max distance from the property that this supply cable will have been earthed ?
Existing PME/TNS supply at service position. Run a minimum of 10mm 3 core SWA cable to your external location, following all approved cable installation procedures. Terminate in to a Metal Clad Dis-Brd. Link SWA Earthing Tag to DB-1's MET with 4mm, despite it being a Metal Clad Dis-Brd. (Belts & Braces!) Drop an Earth Rod in as close as possible to DB-1 and connect back to DB-1's MET with 10mm Bond any metal services entering the remote building with 10mm Bond any exposed metal framework of the building with 10mm Resultant installation has an excellent Ze DB-1 Resultant installation is tied down to 'True Earth' at it's remote location thus avoiding any 'potential' problems! Resultant installation avoids the need for expensive Time delayed RCD Split Boards! Comments and critisim gartefully received! ******! On the RCD side of DB1 ?? Mr. HandyAndy - really