outside sockets with inside switchs

[Jimmer2014]

Hi all
I want to add 2 double sockets outside from a spur with 2 switches so I can isolate them from inside my house.
I was thinking of spurring off a double socket to a fcu then to the 2 switches (unsure what type, maybe double pole) to sockets using 2.5mm t+e.
One socket will be under deck to power lights and the other will above the deck.
My question is, is it ok to run 2 spurs of 1 fcu or is there a better way
Cheers

 

[AndyPRK]

Once you have the 13a fcu you can do what you wish.

If the existing socket isn't protected by a 30ma rcd then fit an rcd fcu.

Use double pole switches.

 

[PrenticeBoyofDerry]

You need first confirm that the socket you are taking the feed from is not a spur if it is a ring final circuit, also that socket should not already be feed a spur. Once we have that confirmed, you can feed a 13A FCU from the feed socket, then it would be possible to take a feed to two separate 20A DP isolator switches, operating the two sockets.
As Andy has mentioned, you will need the additional protection of 30mA RCD, if not already existing, this will be required for buried cable and socket outlets, so if cable is buried less than 50mm with wall and not mechanically protected a RCD/FCU combo would be ideal, if cable not buried then it would be possible to have the RCD protection incorporated at the socket outlets.
If you have exposed external cables they must be suitable or/and suitably protected for that environment, as will any other equipment used outside.

 

[JohnW2]

... if cable is buried less than 50mm with wall and not mechanically protected a RCD/FCU combo would be ideal

That's certainly common sense. However, for those who feel that they have to be strictly compliant with the word of the regs, that approach would presumably leave a (probably very short) length of new cable upstream of the RCD/FCU (going to the socket being spurred from) that was not RCD protected,wouldn't it?

Kind Regards, John

 

[PrenticeBoyofDerry]

There is some discretion that can be applied, with the regards to the likelihood of the cable being mechanically damaged, and if you install the RCD unit as close as possible (manining right next to the feed socket), I doubt you would be able to hang a shelf or picture in that location or would want to!

 

[JohnW2]

There is some discretion that can be applied, with the regards to the likelihood of the cable being mechanically damaged, and if you install the RCD unit as close as possible (manining right next to the feed socket), I doubt you would be able to hang a shelf or picture in that location or would want to!

As I said, I agree totally in terms of common sense, and I certainly would apply that common sense myself. However, I am not one of those who feel constrained by employers, scheme operators, insurers or whoever to work to the strict word of the regulations.

In terms of that 'strict word of the regulations', I must have missed it, because I was not aware that the regulations contained any provision for one to exercise discretion to not RCD protect any new buried cable (>50mm etc.) on the basis that one judged the likelihood of mechanical damage to be low - no matter how sensible such a provision would have been.

Kind Regards, John

 

[EFLImpudence]

As I said, I agree totally in terms of common sense, and I certainly would apply that common sense myself. However, I am not one of those who feel constrained by employers, scheme operators, insurers or whoever to work to the strict word of the regulations.

Fair enough.
Perhaps PBoD agrees.

Although, I presume, you don't think he should impart his discretion on here.

However -

In terms of that 'strict word of the regulations', I must have missed it, because I was not aware that the regulations contained any provision for one to exercise discretion to not RCD protect any new buried cable (<50mm etc.) on the basis that one judged the likelihood of mechanical damage to be low - no matter how sensible such a provision would have been.

If the FCU is next to the socket would the cable be 'buried' or contained in the back boxes?

 

[JohnW2]

As I said, I agree totally in terms of common sense, and I certainly would apply that common sense myself. However, I am not one of those who feel constrained by employers, scheme operators, insurers or whoever to work to the strict word of the regulations.

Fair enough. Perhaps PBoD agrees. Although, I presume, you don't think he should impart his discretion on here.

Given that people's attitudes to such things vary, I personally think that 'the choice' should be explained to OPs. In other words, if 'common sense' or 'discretion' (although I doubt such actually that exists in the regs in relation to this issue) may differ from 'the word of the regs', then I would think that this should be explained to OPs, so that they can decide how concerned they are about 'strict compliance'.

However -

In terms of that 'strict word of the regulations', I must have missed it, because I was not aware that the regulations contained any provision for one to exercise discretion to not RCD protect any new buried cable (<50mm etc.) on the basis that one judged the likelihood of mechanical damage to be low - no matter how sensible such a provision would have been.

If the FCU is next to the socket would the cable be 'buried' or contained in the back boxes?

That's 'scraping the barrel' Whatever, if the faceplates are essentially in contact and the cable is behind them, I would say that would amount to adequate 'mechanical protection'!

However, there is a serious question here. If one is going to apply discretion/common sense, where is the line to be drawn - 3", 6", 12" or what?

Kind Regards, John

 

[EFLImpudence]

That's 'scraping the barrel'

No it isn't.
I don't consider the wires in the back box to be 'buried'.

However, there is a serious question here. If one is going to apply discretion/common sense, where is the line to be drawn - 3", 6", 12" or what?

I'm not sure if it is serious really (more a question for question's sake) because if you were of the opinion that the 12" required RCD protection then, I suppose, you would not have fitted the FCU where you did in the first place.

Conversely, if you felt duty bound to fit another FCU right next to the socket then you won't need the original one.

 

[JohnW2]

No it isn't. I don't consider the wires in the back box to be 'buried'.

Nor do I. I don't think anyone in their right mind would interpret the regs as suggesting that they were - otherwise virtually everything would require RCD protection.

However, there is a serious question here. If one is going to apply discretion/common sense, where is the line to be drawn - 3", 6", 12" or what?

I'm not sure if it is serious really (more a question for question's sake) because if you were of the opinion that the 12" required RCD protection then, I suppose, you would not have fitted the FCU where you did in the first place.

Maybe, but that surely confirms that it is a serious question - since what you've written begs the question as to what would be the minimum spacing (if not 12") below which you would feel it OK to site the FCU. It's really not a silly, hypothetical or 'trick' question - I genuinely would like to know your opinion.

Kind Regards, John

 

[EFLImpudence]

Maybe, but that surely confirms that it is a serious question - since what you've written begs the question as to what would be the minimum spacing (if not 12") below which you would feel it OK to site the FCU. It's really not a silly, hypothetical or 'trick' question - I genuinely would like to know your opinion.

Even if I replied that 1" was a maximum it would not be relevant as there is nothing in the thread to suggest that the problem has arisen.

I thought you raised the question in relation to the cable from the socket to an immediately adjacent FCU.

 

[JohnW2]

Even if I replied that 1" was a maximum it would not be relevant as there is nothing in the thread to suggest that the problem has arisen.

Maybe I've missed it, but I have not noticed any discussion about the siting of the FCU.

I thought you raised the question in relation to the cable from the socket to an immediately adjacent FCU.

No - if we knew that it was 'immediately adjacent' (i.e. touching or nearly touching - maybe even your 1"), then I would not have raised the issue, since we agree that would be silly. It was the suggestion that, if the cables were buried, an RCD FCU would be 'ideal', without any apparent mention or consideration of the distance between socket and FCU which caused me to make my comment about 'strict compliance'.

Kind Regards, John

 

[AndyPRK]

There is some discretion that can be applied, with the regards to the likelihood of the cable being mechanically damaged, and if you install the RCD unit as close as possible (manining right next to the feed socket), I doubt you would be able to hang a shelf or picture in that location or would want to!

Did I just read that as PBoD being pragmatic about RCD protection ?

Someone must of hacked his account

 

[JohnW2]

Did I just read that as PBoD being pragmatic about RCD protection ? ...

Seemingly so - although I didn't admit it, I was quite impressed

Kind Regards, John

 

[EFLImpudence]

No - if we knew that it was 'immediately adjacent' (i.e. touching or nearly touching - maybe even your 1"), then I would not have raised the issue, since we agree that would be silly. It was the suggestion that, if the cables were buried, an RCD FCU would be 'ideal', without any apparent mention or consideration of the distance between socket and FCU which caused me to make my comment about 'strict compliance'.

Ah, ok.

I suppose I'm just used to doing it and not thinking there may be occasions when someone unfamiliar with the work may wrongly site an RCD FCU a long way from a socket necessitating needless discretion.