Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 34 replies
  • Subscribers 32 subscribers
  • Views 4791 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

18th question.

Former Community Member
Former Community Member
Hi all, any comments welcome on this one.
Is it still acceptable to have a socket outlet for a specific use not rcd protected under the 18th?
I fitted a single 13a socket outlet recently in a loft space for one of my regular customers, it is to supply a security camera system and the suppliers asked for a socket to be provided. It is supplied from the first floor lighting circuit which doesn't have rcd protection. (16th. ed. board) There is not the slightest chance of the socket being used to supply anything else and I would like to issue a mwc stating that the socket is only to be used for this specific purpose. If it's a major issue I could get back to the customer and arrange to fit an rcbo but I don't really think that is necessary? Thinking now about going back to change socket for an rcd protected one?
  • 0
    Well spotted Graham about the BS 7288 sockets. I wonder if any of the manufacturers include this in their data sheets?


    Is a "Clik Rose" a socket outlet?
  • 0
    I thought they are in abeyance or possibly purgatory.


    Around forty years ago we had a contract come through from an architect saying that materials that he said were to be removed from site were not to be placed in purgatory, however in this particular case it still looks like the issue resolves around people needing to get their act together and sort out what, if any, is the intended purpose of these fittings rather than the fittings not working, so perhaps they deserve a place in purgatory.


    Andy Betteridge
  • 0

    John Peckham:


    Is a "Clik Rose" a socket outlet?




    I think the standards call them luminaire support couplers John, so in BS 7671 terms they are couplers rather than plugs and socket-outlets.

  • 0
    Graham


    I thought that but was testing the water. Could be the answer for the original post.
  • 0
    The problem is that some LED lighting, such as patio lights that can be installed in timber decking and the like can be installed in kitchen plinths and the like, but they are supplied with a plug in LED driver or transformer.


    So you need a 13-amp socket to plug the lights into the lighting circuit hidden away under the kitchen cabinets or elsewhere as you cannot cut the plug off and hard wire them.


    Similar issues occur with CCTV equipment and the like, it can easily run off a lighting circuit, but needs a plug to plug the mains adapter into.


    Andy B.
  • Former Community Member
    0 Former Community Member

    gkenyon:




    Paul Skyrme:

    My opinion here will deviate from what is stated in BS 7671, and, for some crazy reason that there has been no explanation of the product standard for RCD socket outlets (and fused connection units) have been removed from BS 7671:2018, so that could require a deviation, me, I'd not worry and fit one, including a deviation if necessary.

    The requirement in BS 7671:2018 is that ALL socket outlets in domestic premises must be RCD protected.




    The current version of BS 7288 actually says that additional protection should already be in place within the installation. The last sentence of the first paragraph of Clause 1 of BS 7288:2016 states:

     



    SRCDs are intended for use in circuits where the fault protection and additional protection are already assured upstream of the SRCD.



     




    Yes Graham, I did look up BS 7288, some time after I responded to this thread, but it had disappeared from my forum view by then so I took at as resolved.

    I feel that this is an error, of some kind, in BS 7288, which has resulted in this scenario, and this upstream requirement is the reason that the standard has been omitted from BS 7671.

    This does need to be resolved by BSi/the relevant committee/JPEL64 to give the industry clarity.

    At the moment devices to BS 7288 are really a device without an application, unless you really require redundant RCD protection to ensure that hopefully one goes and you don't care if the two go out in the event of a fault.

  • 0

    Paul Skyrme:



    Yes Graham, I did look up BS 7288, some time after I responded to this thread, but it had disappeared from my forum view by then so I took at as resolved.

    I feel that this is an error, of some kind, in BS 7288, which has resulted in this scenario, and this upstream requirement is the reason that the standard has been omitted from BS 7671.

    This does need to be resolved by BSi/the relevant committee/JPEL64 to give the industry clarity.


    I'm sure that will happen, although JPEL/64 are not responsible for BS 7288, this comes under PEL23/1


    At the moment devices to BS 7288 are really a device without an application, unless you really require redundant RCD protection to ensure that hopefully one goes and you don't care if the two go out in the event of a fault.



    Agreed. There are a number of situations that such devices provide the best solution to Additional Protection for.


    It should be noted as a final technical note, that SRCDs are not really an answer for fault protection (i.e. can't meet disconnection times) because they can't respond to an upstream fault. They can therefore only be used for additional protection - but I think most that specify them are aware of this limitation.

  • 0

    Sparkingchip:

    The problem is that some LED lighting, such as patio lights that can be installed in timber decking and the like can be installed in kitchen plinths and the like, but they are supplied with a plug in LED driver or transformer.


    So you need a 13-amp socket to plug the lights into the lighting circuit hidden away under the kitchen cabinets or elsewhere as you cannot cut the plug off and hard wire them.


    Similar issues occur with CCTV equipment and the like, it can easily run off a lighting circuit, but needs a plug to plug the mains adapter into.


    Andy B.




    But the moving goal post requires all domestic lighting circuits and cables in walls to be RCD, introducing more what ifs.


    Andy B. 

  • 0

    It should be noted as a final technical note, that SRCDs are not really an answer for fault protection (i.e. can't meet disconnection times) because they can't respond to an upstream fault. They can therefore only be used for additional protection



    Could you clarify that Graham? It sounds like you're saying that a SRCD/FCURCD might be too slow to provide the 0.4s or 0.2s disconnection required for ADS - which sounds rather odd to me (given they'd typically open in something like 40ms for most credible L-PE faults of negligible impedance). Naturally they can't provide protection from upstream faults - but then neither can any other protective device - faults on a distribution circuit imposing hazardous voltages for hazardous durations on downstream final circuits is a well known general problem - there's nothing peculiarly lacking in a BS 7288 device on that count.  A SRCD may rely on an upstream overcurrent protective device for backup protection in the case of large fault currents - but the same is true of DIN rail mounted RCCBs - they often have a breaking capacity not more than 3kA.


    Then there's the situation where Zs at the point where thee BS 7288 device is installed is fine for the upstream MCB, but the additional wiring downstream increases Zs beyond that limit (whether fixed wiring from a FCURCD or an extension lead from a SRCD) - are you suggesting that the BS 7288 device shouldn't be relied upon to provide ADS downstream - just additional protection - and so some other means of ensuring ADS downstream needs to be provided in addition?


       - Andy.
  • 0
    These devices rely on a BS1362 fuse to provide fault protection downstream of them either in a plug or an integrated fuse holder, but these have to be protected by another protective device upstream of them.


    The only time I can remember seeing a RCD socket that may have been relying on its RCD to provide fault protection downstream of it was in my Dad’s detached garage, a mate of his was a DNO electrician and installed the RCD socket with the live and neutral brought through from the house which was protected by an VOELCB, but with the socket earth terminal connected to a rod so the earthing systems were both TT, but not hardwired together.


    So I guess that meant RCD socket was providing fault protection downstream of it rather than the VOELCB, either that or I am over thinking it.


    That was a fair few years ago.


     Andy B.

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines