Exporting the earth?

[Robo]

Im not 100% on earthing for submains. If the supply is tnc-s you are not ment to export the earthfrom db to say a detached garage?If i did export the earth could it not be classed as TNS instead?? Or to keep it TNCS run a seperate earth form cutout.Or just have the garage as a TT.

Are you aloud to export TNS from 1 db to another?

Or i could rod the garage and then it would be seperate?

 

[antimatter]

Under the Electricity safety, quality and continuity regulations 2002 you cannot use a suppliers earth to an out building, on a TNC-S Earthing arrangement, so the detached garage effectively becomes a TT installation with an earth electrode installed in the ground.

If you use SWA to supply the garage the armour must not be terminated at the garage end of the cable.

 

[tony mc]

Bit unsure re your TNCS to TNS

If you create a new earth at the garage that would have to be via a rod so it would be TT.

If you were to continue with a earth from the TNCS system it would remain that system and not change to TNS. Some DNO companys don't like you exporting it.


How far away is the detached garage and don't forget to bond in the garage.

 

[j.mawer]

http://www.electriciansforums.net/e...159-good-guide-exported-pme-outbuildings.html

 

[DurhamSparky]

if you have no Water or Gas in Garage just carry earth to the garage!!

if you are bonding i would SWA 2 Core and rod in garage!!

 

[Robo]

Bit unsure re your TNCS to TNS

If you create a new earth at the garage that would have to be via a rod so it would be TT.

If you were to continue with a earth from the TNCS system it would remain that system and not change to TNS. Some DNO companys don't like you exporting it.


How far away is the detached garage and don't forget to bond in the garage.

I dont actually have a job, im just enquiring for the future. Would it be ok to gland garage end and just not connect into earth bar, providing its insulated. If it was metal then use a stuffing gland and dont bother with armours.

 

[DurhamSparky]

always earth the armour!!!

 

[IQ Electrical]

Under the Electricity safety, quality and continuity regulations 2002 you cannot use a suppliers earth to an out building, on a TNC-S Earthing arrangement, so the detached garage effectively becomes a TT installation with an earth electrode installed in the ground.

If you use SWA to supply the garage the armour must not be terminated at the garage end of the cable.

That is absolutely incorrect, please read the Guide that I posted and Guidance Note 8.



This is the link to the thread: http://www.electriciansforums.net/e...159-good-guide-exported-pme-outbuildings.html

 

[tony mc]

If you are useing the earth from the TNC-S to protect the swa cable and then isolating it from the garage which now becomes TT.

I would use a insulated box so that both earths are kept seperate so you are only transporting the line conductors.

 

[Engineer54]

Seems the myths and mis-information on this topic continues... To my mind, Rods (TT) should always be considered as your last choice, not a first choice!!!