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Ampo

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Hi all, could I have opinions on the use of rcd fused please.
Customer has old 3036 at the front of the house.
They want a couple points on there new decking for festoon type lighting switch from inside.
There is a t and e switch fed outside light already so I'm thinking of coming off this to an outside rcd fcu which can feed the first set of lights and then swa to the next standard fcu (fed from load side of the first).

The client wanted sockets instead of spurs but I have said this isn't possible without finding the ring circuit inside the house so they will have to choose non transformer lights.

This will ensure all new stuff is protected. My issue is with the rcd not being to 61008 or 61009. I'm sure I've read that this is a problem but I'm looking at the big book and can't find it
 
The issue with RCD sockets and RCD FCUs is that they fall under BS EN 7288, which is not listed among the allowable standards. There is not a regulation that says we cannot use them.
There has been much debate, but if I recall correctly, most are in favour of not using them for additional protection, as they don't meet the requirements for additional protection.
 
For the requirements of BS7671 an rcd spur does not satisfy as a device for providing additional protection. You would have to list it as a departure a prove its use provides the same level protection as that required by BS7671.
 
Just to add that we can't allow ourselves to be swayed by what the customer wants, if we can't do what they want within acceptable standards and regulations.
I would either find a way to do the job that's within the regulations, or walk away and let someone else do the job.
 
The issue with RCD sockets and RCD FCUs is that they fall under BS EN 7288, which is not listed among the allowable standards. There is not a regulation that says we cannot use them.
There has been much debate, but if I recall correctly, most are in favour of not using them for additional protection, as they don't meet the requirements for additional protection.
I believe there was an article in "Connections", the NICEIC magazine, that states that 7288 RCDs are considered acceptable as additional protection in the NICEIC's view. (Though it is as pointed out a deviation from BS7671 at the moment).

What that opinion is worth is up to the installer I guess - I did save a copy for reference so I'll see if I can find it...
 
There's more on this in this previous thread:
The Connections article is in post 13.

 
There's more on this in this previous thread:

That has the screenshot I obviously saw, though also some conflicting advice from elsewhere ?‍♂️

Though it seems there has been a new version of the standard BS 7288 standard (2019 previously 2016) that has more onerous requirements, but without access to the standards I have no idea if it's made them more or less suitable..

Anyone notice if they put them back in for the DPC for AMD 2?
 
Just to add that we can't allow ourselves to be swayed by what the customer wants, if we can't do what they want within acceptable standards and regulations.
I would either find a way to do the job that's within the regulations, or walk away and let someone else do the job.
Absolutely agree, and I have a reputation in my area to uphold. Its also important from the other side of the coin though where I'm not looking to inflate unnecessary work off pensioners. Its a balancing act. In this instance if it can't be done simply they will go without, no budget for the db at present unfortunately but I hear what your saying
 
why not fit a 61008 adjacent to CU, feed from RFC fuse, and then protect the whole of the RFC; then tap off the RFC for your outside works.
 
why not fit a 61008 adjacent to CU, feed from RFC fuse, and then protect the whole of the RFC; then tap off the RFC for your outside works.
That may be an option though I'd need to do some additional tests before I put the whole circuit on. I think in this instance budget is a rcd spur or nowt unfortunately
 
That may be an option though I'd need to do some additional tests before I put the whole circuit on. I think in this instance budget is a rcd spur or nowt unfortunately
all depends on the state of the RFC> a stand alone RCD will probably be kicking round in the back of your van (there's 6 in my van, various makes), dead money. all you need is an enclosure.
 
One of the curious aspects of the whole RCD-FCU issue is no one has come forward to say why the don't conform for additional protection. Or indeed what the "supplementary protection" is that they do provide.

There was an IET Q&A that just repeated some weaselly statement about standards, but did not say anything helpful. Someone could easily have given details, e.g. if the FCU standard lacks some aspect so some models are OK and other marginal, etc. But nothing, Which makes me deeply suspicions that is the reason: they are not willing to call out any make/model as not good enough since it meets the letter of the 7288 standard but lacks something obvious/adequate that 61008 has.

So if it has to be a FCU then at least get one of the reputable brands that gives the break capacity, etc, in the data sheet.
 
Beama's RCD handbook has a table on p22 listing various RC devices and their suitability for certain applications. The only significant difference listed between a FCURCD and an RCCB or RCBO seems to be that they are not suitable for 'fixed wiring protection'. Exactly what is meant by that I am unsure.

They are however listed as suitable for personal protection (additional protection of persons or livestock against direct contact), protection against electrical fire, socket outlets 20A or less, and portable appliances 20A or less.

 
Beama's RCD handbook has a table on p22 listing various RC devices and their suitability for certain applications.
That is quite a useful guide book!
The only significant difference listed between a FCURCD and an RCCB or RCBO seems to be that they are not suitable for 'fixed wiring protection'. Exactly what is meant by that I am unsure.
Exactly!

One obvious limit is the FCU-RCD is limited to the 13A fuse so it can't really be used for anything beyond the equivalent of a fused spur or lighting circuit. Of course, in many cases (like this thread) that is exactly what is desired and it would appear they are sufficient for that job.

After all, what really is the difference between fixed wiring (that meets this <= 13A current limit) and flexible cables like an extension lead in terms of necessary protection?
 
In my eyes the whole thing with rcd spurs/sockets is unclear maybe why they are not included in BS7671. I certainly wouldn't want to be explaining if the worst was to happen why I employed one as opposed to following the requirements of BS7671.
 
That is quite a useful guide book!

Exactly!

One obvious limit is the FCU-RCD is limited to the 13A fuse so it can't really be used for anything beyond the equivalent of a fused spur or lighting circuit. Of course, in many cases (like this thread) that is exactly what is desired and it would appear they are sufficient for that job.

After all, what really is the difference between fixed wiring (that meets this <= 13A current limit) and flexible cables like an extension lead in terms of necessary protection?
I struggle to see why using FCURCDs for additional protection would be a problem for minor additions and alterations, and do use them occasionally where the CU is obsolete and RCBOs are not available.

I've just sent an email to greenbrook (powerbreaker FCURCDs) to see if they can shed any light. Will update if/when a reply comes
 
I struggle to see why using FCURCDs for additional protection would be a problem for minor additions and alterations, and do use them occasionally where the CU is obsolete and RCBOs are not available.

I've just sent an email to greenbrook (powerbreaker FCURCDs) to see if they can shed any light. Will update if/when a reply comes
Will be very interesting to see what they come back with.

If they don't meet the 7671 requirements for additional protection, then in a domestic setting I don't really see what their intended usage would be, apart from maybe to comply with manufacturers instructions on a fixed load that wouldn't require an RCD otherwise? Any property needing them for fault protection would generally not be solved with a single FCU, or even RCD sockets everywhere.

The manufacturers of them certainly push them to the domestic market as a way of adding 'protection', but maybe they are careful to never claim they can add 'required' protection.

I've used them on occasions on minor works where a single socket or light is being added and there is not a simple solution at the CU without a complete board change, which the job does not justify. They seem like they should be a perfect solution to that problem.
 
That has the screenshot I obviously saw, though also some conflicting advice from elsewhere ?‍♂️

Though it seems there has been a new version of the standard BS 7288 standard (2019 previously 2016) that has more onerous requirements, but without access to the standards I have no idea if it's made them more or less suitable..

Anyone notice if they put them back in for the DPC for AMD 2?
I looked it up and they haven't added them back in it appears (not in 531.3.4.1 at least)

Having said that it doesn't mention older standards such as 4293 either - so is that station the position that adding a socket onto an older but functioning BS4293 board would automatically not be compliant with BS7671?
 
Wow thanks for all the responses, its clear to me that this subject is far from clear. Its a shame as it's a really important thing for us to have a definitive answer on. There are situations such as mine where a straight forward job can become awkward if we can't use them. I used to think they were fine and have added towel rails and so on in the past using them. In this instance with a couple outside 3a spurs I really can't see why the regs wouldn't allow it, seems overkill. I think the the end result of these sort of grey areas is that I won't be able to do it and then a less "awkward expensive" spark will simply chuck in standard spurs and walk away.
 

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