Outdoor lights and sockets - same or separate circuits?

[blup]

Hello

I won't be doing the work myself, just adding to an ever growing list of things for an electrician to do.

I'd like to have outdoor sockets and lighting and I have an RCD protected ring circuit in the utility room which only has the washing machine and tumble dryer on it, no other sockets.

I'm not planning anything major for the garden, just some lights and somewhere to play music, maybe run a hedge trimmer from time to time. Am I right in thinking that you could add a 13A fused spur before adding weatherproof outdoor sockets on a radial circuit? And then the garden lights could plug into one of the sockets ? If so, is it better to use armoured cable or run normal cable in plastic conduit?

Or should it have its own consumer unit like in a garage and the lights should be separate from the sockets? Thanks

Whether you use armoured cable or flex or nyy-j, you need to base your decision on appearance and safety to avoid you or a third party slicing through a cable that is covered but not buried.

 

[securespark]

Adding an FCU to an existing circuit is not creating another circuit.

All you are doing is extending an existing circuit, allowed under the rules, but fusing it down.

The current situation is that the status quo has been allowed to continue and no one in an official capacity has intervened and suggested otherwise.

 

[ebee]

Adding an FCU to an existing circuit is not creating another circuit.

All you are doing is extending an existing circuit, allowed under the rules, but fusing it down.

The current situation is that the status quo has been allowed to continue and no one in an official capacity has intervened and suggested otherwise.

Therefore after the cutout in my home i have my own existing switchfuse of 32A feeding 10 radial circuits in 2.5 T&E to 10 FCUs each containing a fuse in order for me to run some power circuits and lighting circuits etc so I have only 1 circuit or only 2 circuits then?

 

[SJRSJR]

Thanks for everyone’s input, it’s an interesting read. My post is just me thinking ahead and wanting to understand what might be involved. I have an electrican who’ll be doing other notifiable work so I guess he’ll decide.

 

[JohnW2]

A spur is obviously part of an existing circuit not a new circuit.

As you say, it is "obvious" to most of us, and presumably was even obvious in the minds of those who wrote the pre-2013 (in England, still in Wales) notification rules - since adding a fused spur to an existing circuit was then one of the few things which was explicitly NOT notifiable.

However one should not really have to utilise common sense (or presumptions about the intent of the authors of regs/laws to 'over-ride' what is actually written in the regulations and legislation. I would say that the real problem is that the Building Regs (hance notification rules) do not define "circuit" (hence "new circuit") so people rely on BS 7671 definitions - and by those definitions, an FCU creates "a circuit" separate from the one from which it is derived - so, if the FCU and things downstream of it are 'new', then adding it would be notifiable, daft though that is.

 

[securespark]

Therefore after the cutout in my home i have my own existing switchfuse of 32A feeding 10 radial circuits in 2.5 T&E to 10 FCUs each containing a fuse in order for me to run some power circuits and lighting circuits etc so I have only 1 circuit or only 2 circuits then?

Well, never mind the FCUs, why have you decided to run 10 circuits in 2.5 off a 32A fuse?

 

[JohnD]

Outdoor circuits are rather prone to RCD trips from rain or damp penetration.


So it would be preferable to have separate circuits protected by their own RCD or RCBO.

 

[ebee]

Well, never mind the FCUs, why have you decided to run 10 circuits in 2.5 off a 32A fuse?

Ring or radial on a 2.5 T&E on a 32A OPD is not uncommon.

With a ring we might have a number of spurs (common example being a number of points (sockets say) and from each of those points we might have a radial consisting of one end point each, again in 2.5 T&E, all allowed and nobody seems alarmed by any potential problems.
So far so good?

We might run a radial of 2.5 T&E on a 16A or 20A MCB and we might even run a spur from each point on the radial consisting of one point only on each spur.
We might at some points branch off and branch off and branch off in a design known as "trees" .
Mightbe a beggar to inspect and test and then write down the result but heyho its allowed.
So far so good?

We might have ten or more or less radials each connecting to one fuseway at one end and each connecting to one point only at the other end, once again all cables are 2,5 T&E.
We might decide that it does not comply with BS7671 but some might decide that it does.
However, is it potentially any less safe than the examples above?
So far so good?

We might have a radial circuit of 4.0 T&E or even 6.0 T&E if the terminals on the points accept those whilst still being electrically and mechnically sound and we might similarly run a 2.5 spur to a point on each one.

Some of those might be considered as "standard circuits" whilst some might not.

Is something not easily recognised as a standard circuit still allowed by BS7671? Yes.

Could something not complying with BS7671 be potentially unsafe? It might be or it might not..

Is something not as easy to test and inspect to BS7671 still permitted? Yes.

So far so good?

The over riding aim is safety of people, livestock and property!
So far so good?

Anyway i have not decided to run 10 circuits in 2.5 T&E on a 32A fuse (or breaker) and I never would. But what if I did? Would it be unsafe?

 

[ebee]

I noticed in a house a few years back, repurposed I think.
30A MCB running 6.0 T&E to a, bog standard, immersion heater in a cylinder then from that one a piece of 2.5 T&E to a similar immersion heater in a second cylinder .
An EICR had been done ( actually I think it was a PIR, same thing really), and it was defected as "not allowed".
I did wonder what tgat inspector perceived to be the problem really!

That house had become a care home

 

[EFLImpudence]

Anyway i have not decided to run 10 circuits in 2.5 T&E on a 32A fuse (or breaker) and I never would. But what if I did?

Wouldn't that be one circuit?

I noticed in a house a few years back, repurposed I think.
30A MCB running 6.0 T&E to a, bog standard, immersion heater in a cylinder then from that one a piece of 2.5 T&E to a similar immersion heater in a second cylinder .
An EICR had been done ( actually I think it was a PIR, same thing really), and it was defected as "not allowed".

I too have come across people getting things wrong.

That house had become a care home

Oh well, there you go.

 

[Ragnar_AT]

Is the current circuit on an RCD with other circuits or on its own RCBO? If the latter and it only serves laundry appliances I‘d say spurring off this circuit is fine, otherwise I‘d recommend adding an extra RCBO as JohnD suggested.