Bonding Structural Steel on farm building, TN system?

[vde-electrician]

On a TN system , i want to bond the structural steel on a farm shed. But the submain across to the farm shed is only 10mm Twin and Earth, so only a 4mm cpc is supplied? I was going to install a 10mm cpc to the steel from the local shed db? any help please.

 

[jamie-spark]

It's 6mm MINIMUM it depends in the supply at he Origin. the bond to the shed needs upgraded or isolated and made a TT system. Who supplies a sub db especially on a farm in t&e

 

[jamie-spark]

Or drink beer glug

 

[vde-electrician]

yes - i may suggest replacing the overhead submain - (you find these alot in older farms) if its a problem - then yes i will isolate the earth in the shed on that sub main , and install an earth rod local - with only a 6mm to the steel. I would only use a main switch in this shed db, as the supply t&e is covered by a 30mA RCD. would you agree?

 

[Knobhead]

I don't help DIYers

 

[Sintra]

yes - i may suggest replacing the overhead submain - (you find these alot in older farms) if its a problem - then yes i will isolate the earth in the shed on that sub main , and install an earth rod local - with only a 6mm to the steel. I would only use a main switch in this shed db, as the supply t&e is covered by a 30mA RCD. would you agree?

Reading through some of your other posts regarding "this farm" you appear to be well outside your comfort zone.

 

[MDJ]

i want to bond the structural steel on a farm shed. .

Do you? Explain why and we may chip in

 

[JD6400]

Obviously I have not seen this job in person , but even so I feel confident enough from what you have mentioned in other posts , that this farm will be nowhere near the required speck to allow any other head connection than TT .