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Add RCD to Shed supply and update

Discussion in 'Electrics UK' started by northbank_dom, 2 Sep 2021.

  1. Adam_151

    Adam_151

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    If theres no RCD protection to the stuff in the shed at the moment, then swapping the FCU it comes off to an RCD one will make things much safer.

    Yes, we all here know theres issues of the wording of the regs not recognising BS7288, but having that minor issue is a whole lot better than not bothering at all because its not as simple as changing an accessory. Perfect being the enemy of good and all
     
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  3. northbank_dom

    northbank_dom

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    This was my thoughts. It’s not a new concealed cable, it’s the existing one. The entire run to the shed is as it was, but I’m happy to make improvements where I can and have a pro do it. I just want to avoid running a new cable if possible, which I believed was ok if you’re not creating a new spur/circuit.
     
  4. yorkspark

    yorkspark

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    if you want to improve the circuit and fit an outside socket, then i would recommend terminating the incoming cable from the fuse spur into a metal enclosure fitted with a 16amp rcbo, then from there a cable to your sockets and spur for lighting.
     
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  5. JohnD

    JohnD

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    Unfortunately I do not have access to a copy. "Only intended" is not the same thing.

    Can you tell me the actual wording that explicitly says they CANNOT be fitted?

    What is the penalty for fitting them?
     
  6. northbank_dom

    northbank_dom

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    Sounds sensible. I can get the enclosure fitted in line then get a pro to complete the actual wiring. Thanks for the suggestion.
     
  7. ericmark

    ericmark

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    I note a lot of talk on the IET website over BS 7288 and it being missed off the list in BS 7671, no one seems to know why they have been missed off, and scheme member electricians have to do what the scheme provider says, so if the scheme provider says you must follow BS 7671 and not use BS 7288 then they must do that.

    However for non scheme members, it is up to them what they do, and it needs some common sense. It does seem some times common sense is lacking, I looked at a Masterplug Mode 2 Charger with idea could use for garden tools and visitors cars, however when one reads the spec, it says it must be supplied from a type B RCD so it does seem rather pointless marketing the units to start with.

    So in real terms you have to decide what your going to do, personally I swapped the fusebox and CU for a new CU with all RCBO's and still got it wrong and fitted type AC instead of type A. So I had to decide if worth it to swap them, and I decided unlikely to be a problem so stayed with type AC.

    We can't tell you what to do, you have to decide what is reasonable.
     
  8. flameport

    flameport

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    It wasn't missed - there was a deliberate choice to remove references to it from BS7671, as the latest version of BS7288 states that the devices are not suitable for additional protection, and are therefore entirely useless.

    That wording in BS7288 may well be wrong, but those that oversee BS7671 only had two options - leave a reference to an apparently useless standard in, or remove it entirely.
     
  9. winston1

    winston1

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    Why? It is being fed from a 13amp fused spur. 16 amp RCBO is pointless. A plain RCD is all that is required.
     
    Last edited: 3 Sep 2021
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  11. northbank_dom

    northbank_dom

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    Do you mean RCD FCU? (Genuine question). As per my original diagram.
     
  12. JohnD

    JohnD

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    are they explicitly forbidden?
     
  13. EFLImpudence

    EFLImpudence

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    Additional protection is not a specific entity in itself for which accessories are either suitable or not.

    It merely means it is extra so if added then it is additional.
     
  14. 333rocky333

    333rocky333

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    That would also provide the DP isolation that the OP says he
    wants
     
  15. winston1

    winston1

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    No. I mean a RCD. It is already being fed by a FCU. Another is unnecessary.
     
  16. conny

    conny

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    If you decide to remove the 13A FCU and use 'something else' then the number of sockets MAY depend on the size of the buried cable.
    If it's 4.0mm or bigger then there will be no problem. However, if it is only 2.5mm, (or even smaller), then you should only have 1 x 13A socket in the circuit as it is spurred off the back of another socket on a 32A ring circuit.
     
  17. northbank_dom

    northbank_dom

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    Isn’t that only if it’s unfused?
     
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