Shed Feed (Hypothetical)

[Cookie]

Say you had to feed power to a shed/detached garage in the UK with a sub unit inside it. How would you go about the earthing? What earthing arraignments can be used at the shed if the home is:

TN-S
TN-C-S
TT

And do you always need an earth rod at the shed?

 

[littlespark]

USA flag but asking about UK earthing arrangements?
Using a vpn?

 

[Cookie]

I'm learning. And yahhh, could be using some VPN

 

[davesparks]

Say you had to feed power to a shed/detached garage in the UK with a sub unit inside it. How would you go about the earthing? What earthing arraignments can be used at the shed if the home is:

TN-S
TN-C-S
TT

And do you always need an earth rod at the shed?

The earthing arrangement used would normally be whatever the incoming supply is, for a domestic shed there is rarely a need to create a seperate TT earth.

If there are any extraneous conductive parts in the shed then the cpc of the distribution circuit will need to be big enough to provide main bonding.
If this is not possible then that is when a TT system seperate from the house installation would need to be created. The largest main bond normally required in domestic is 10mm so its not usually a problem to provide a main bond at a shed if required.

On larger installations it could be prohibitively expensive to run a main bond to a seperate building and so a TT earth would be set up there.
For example if a small outbuilding has a 10mm supply cable but the installation requires 50mm main bonding it could be prohibitively expensive to run a main bond to it.

 

[Cookie]

Dumb question- why would a larger bond force TT earthing in a separate structure?

 

[davesparks]

Dumb question- why would a larger bond force TT earthing in a separate structure?

As I said earlier, it would be prohibitively expensive to run, for example, a 50mm main bond alongside a 10mm supply cable.

 

[Cookie]

I see.

This video has me curious. It looks like he isolated the SWA armor and then made a separate TT earthing system at the workshop?

View: https://youtu.be/Pxrz1oFFEXE?t=1481

 

[davesparks]

I see.

This video has me curious. It looks like he isolated the SWA armor and then made a separate TT earthing system at the workshop?
View: https://youtu.be/Pxrz1oFFEXE?t=1481

I haven't looked but he probably does, just because someone has posted a video on YouTube it doesn't mean they know what they are doing.

There are a lot of people in this country who will follow what their mate in the pub told them rather than reading and understanding the regulations.

 

[Cookie]

Honestly, I think its like that most everywhere.