Supply to outbuilding

[davesch]

Situation is garden summerhouse fed by own 16A RCBO in consumer unit in garage over 4mm2 (overkill !) SWA . At summerhouse this goes to sockets (no FCU) and to lights via FCU with 5A fuse. The lights are all LED so consuming minimal current From the searches I've done it would seem that is okay, but one website claims - "Outbuildings, Garages and Sheds are all required to have their own fuseboard or consumer unit under the BS7671 regulations". It doesn't say where the reg say that, does anyone know, or is this rubbish ?

 

[davesparks]

Situation is garden summerhouse fed by own 16A RCBO in consumer unit in garage over 4mm2 (overkill !)

Why is that overkill?

From the searches I've done it would seem that is okay, but one website claims - "Outbuildings, Garages and Sheds are all required to have their own fuseboard or consumer unit under the BS7671 regulations". It doesn't say where the reg say that, does anyone know, or is this rubbish ?

It is rubbish, there is nothing in BS7671 to support this.

 

[davesch]

Why is that overkill?


It is rubbish, there is nothing in BS7671 to support this.

Sorry my mistake, 6mm2

 

[mainline]

Sorry my mistake, 6mm2

How is the swa terminated ?

 

[davesch]

How is the swa terminated ?

In a metal adaptable box using SWA gland. Twin and Earth cable via plastic glands to FCU and Sockets

 

[davesparks]

Sorry my mistake, 6mm2

OK, but still the same question, why is that overkill?

 

[davesch]

OK, but still the same question, why is that overkill?

Well it's rated a lot higher than needed, but no harm in that I suppose, might have been all they had to hand.

 

[mainline]

In a metal adaptable box using SWA gland. Twin and Earth cable via plastic glands to FCU and Sockets

What about the house end ?

Is there anything extraneous in the summer house ?

What type of earthing system ?

 

[davesch]

What about the house end ?

Is there anything extraneous in the summer house ?

What type of earthing system ?

Terminated via SWA gland onto an 18th edition RCBO CU, nothing extraneous in the summer house. I believe it's TN-S, but actually asking on behalf of a friend who recently moved into the property and wanted to check it had all been done correctly and in particular whether there should have been a CU fitted in the summer house, hence my search and coming accross that website I quoted in the initial posting.

 

[snowhead]

4mm² or 6mm² won't be overkill when someone comes along later wanting a Hot tub or heater or something else added.
Maybe the original installer expected to be called back or the customer asked for extra capacity.

 

[davesch]

4mm² or 6mm² won't be overkill when someone comes along later wanting a Hot tub or heater or something else added.
Maybe the original installer expected to be called back or the customer asked for extra capacity.

Fair comment on reflection

 

[mainline]

Terminated via SWA gland onto an 18th edition RCBO CU, nothing extraneous in the summer house. I believe it's TN-S, but actually asking on behalf of a friend who recently moved into the property and wanted to check it had all been done correctly and in particular whether there should have been a CU fitted in the summer house, hence my search and coming accross that website I quoted in the initial posting.

Sounds fine but without it being actually tested then who knows.

I personally would have used a garage type CU as they are as cheap as chips.
Looks better
Easily add/alter
Save the cost of an adaptable box and fcu
Easier to isolate.

 

[davesparks]

Well it's rated a lot higher than needed, but no harm in that I suppose, might have been all they had to hand.

Not necessarily, how long is the cable?

 

[davesch]

Not necessarily, how long is the cable?

It's only a very short garden,