2 Questions

[iamgary25]

What is at the far end? Shed, garage, house, etc.

The price difference between 2core and 3core will be about £1 a meter so about £70. You will more than likely recoup this in labour/material if you don't make the far end a TT arrangement.

Is there anything extraneous at the far end?

Its a big storage shed with steel structure

 

[Leesparkykent]

What's the IB out of interest?

 

[iamgary25]

What's the IB out of interest?

Only 20A but its Voltage drop we need to keep low.

 

[Leesparkykent]

If you go down the route of making the far end TT, the glands Simon linked to are good or gland in to a plastic dappy box.

 

[iamgary25]

If you go down the route of making the far end TT, the glands Simon linked to are good or gland in to a plastic dappy box.

ok, thanks for your help, i am trying to do the job properly, i don't know everything and when i don't i try and find out, and asking someone is sometimes easier, as i couldn't find anything in the book, and i've been told to do it incorrectly by other electricians

 

[Leesparkykent]

ok, thanks for your help, i am trying to do the job properly, i don't know everything and when i don't i try and find out, and asking someone is sometimes easier, as i couldn't find anything in the book, and i've been told to do it incorrectly by other electricians

The armour or any protective conductor in the cable must not be connected to and must not be simultaneously-accessible with any exposed-conductive-parts in the outbuilding if the outbuilding is being made TT.

 

[telectrix]

by far the better method is to use 3 core SWA. it's 25mm, so the 3rd core is more than adequate for bonding, even if it's PME. the extra cost in using 3 core is outweighed by the fact that you won,t need to install earth rods to end up with a pitiful 10 ohm or greater Ra.

and without getting my brain in gear after ale, i'm sure 16mm would give a within limits VD. ( going by your 20A and 70m. about 6V off top of head)

 

[iamgary25]

by far the better method is to use 3 core SWA. it's 25mm, so the 3rd core is more than adequate for bonding, even if it's PME. the extra cost in using 3 core is outweighed by the fact that you won,t need to install earth rods to end up with a pitiful 10 ohm or greater Ra.

and without getting my brain in gear after ale, i'm sure 16mm would give a within limits VD. ( going by your 20A and 70m. about 6V off top of head)

thankyou, advice taken, and its for solar PV so only have 1%