Earthing of workshop out building

[i_am_fubar]

I know this has been discussed a lot, and there are a LOT of conflicted opinions going about and though I would try and get a definitive answer for my specific situation.

The main property has TN-S earthing.

The workshop is brick construction with no pipes or steel framework. Situated aprox. 15 meters from the house.

The supply is split prior to the CU in a 100A block. Feeds are then taken to the house CU and a 60A fused isolator for the workshop.

I'm going to run 16mm SWA to the workshop and have a full size CU there.

So, the question. Do I connect to house earth, or fit a separate earth spike?

Cheers,
Fubar.

 

[EFLImpudence]

House.

If you really are fitting 16mm² there will be no problem.
10mm² would do and still be fine.

 

[i_am_fubar]

I'm thinking I may end up upping to 100A at some point. Plus some possible big inductive loads. Hence the 16.

So, if I earth at house, I'll need 3 core and run earth as a core itself?

Cheers,
Fubar.

 

[EFLImpudence]

So, if I earth at house, I'll need 3 core and run earth as a core itself?

That would be ideal.

16mm² is only rated up to 87A. You will need 25mm² for 100A.

Do you know the rating of the main fuse?
It may have a 100A label but that is the rating of the cut out itself; not a statement of the actual fuse fitted.

You may have to contact the DNO to ascertain the suitability of the supply for the extra demand.

That doesn't stop you installing the circuit, of course.

 

[i_am_fubar]

Main incomer is only 60A. I doubt I'll ever exceed that. And can't really justify going to 25mm for the price. So guess I'll stick with 60A.

If I ever start needing that much juice, I'll probably just get a 3ph line fitted. Could get a very nice lathe if I did

Fubar.

 

[JohnW2]

If I ever start needing that much juice, I'll probably just get a 3ph line fitted. Could get a very nice lathe if I did

You probably couldn't - by the time you had paid for the new 3-phase supply, you probably wouldn't have any money left to buy a nice lathe

Kind Regards, John