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Shaver socket - How do zones work when a bath is diagonal

Discussion in 'Electrics UK' started by swinster, 9 Dec 2008.

  1. swinster

    swinster

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    Hi,

    We are wanting to install a shaver socket and was intending to run the cable up the wall and across to the ceiling rose as advised by our electrician (although I sometime think that qualified sparks don't always follow code).

    However, our bath is an open claw foot thing and is positioned diagonally across the room. How are the zones affected by this placement?

    I have also read lots of contradictory comments regarding how these things should be wired. Should they be wired through a fused switch - in which case we would need to run cable up the wall then to an outside point then to a lighting main. Should they be protected by RCD (although the whole CU is protected via an RCCB).
     
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  3. Spark123

    Spark123

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    The zones will also be diagonal :idea:

    All circuits in a bathroom need to be RCD protected (30mA max) under 17th edn regs, off the lighting circuit is fine.
    Your whole house shouldn't be protected by one RCD
    Also - if you are in England/Wales this work will be notifiable under part p.
     
  4. swinster

    swinster

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    Does this mean that I would have to extend imaginagy lines from the side of the bath (I think i will put up a floor plan to show what I mean)

    The majority of the electrics we're wire around 15 years ago. I have been reading that lighting circuits SHOULDN'T be RCD protected, but in our case this is NOT true. All the MCBs in the CU connect via a single RCCB (in fact, we recently extended to the basement a couple of years back where a second CU was installed which also uses a single RCCB to protect ALL circuits!)

    This is one reason I don't trust ANY qualified electritians and I like to find independent advise.

    Also, I've read contradictory advice about shaver sockets in zone placements. Some say zone 3, other say zone 2 is fine.
     
  5. rebuke

    rebuke

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    zone 3 doesn't exist in the current regs, just 1 and 2. It's fine to put a shaver scoket in zone 2, as long as it has an isolating transformer compliant with BS EN 61558-2-5...
     
  6. Spark123

    Spark123

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    Yeah.

    Lighting circuit which have concealled cables in a wall less than 50mm should be RCD protected under the 17th edition regs. Also, all circuits in a bathroom should be RCD protected to 17th regs.
    The problem with protecting everything with a single device is if it trips it can cause a hazard (i.e. if you are using a drill etc) and if it won't reset then it is a major inconvenience.
    Hmmmmm - talk about a red rag to a bull :LOL:
    Under the 17th Zone 3 doesn't exist anymore, a shaver unit to BS EN 61558-2-5 can be installed in zone 2.
     
  7. swinster

    swinster

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    OK. I would suspect that the vast majority of the house lighting wiring (if not all) is buried in plaster on the brick walls less than 50mm deep. I can't see that even those in stud walls won't be greater than 50mm. So I guess that the lighting circuits in this instance DO need to be RCD protected. However, I suspect what you are referring to is to have the circuits subdivided at the CU so that say mains circuits are protected by one RCCB and lighting are protect by another. I'm not sure how big a job this is or even if it requires a new CU. I know the work downstairs is a couple of years old and was put in before Part P came in to force (circa 2005), but I guess these circuits should also have been split.

    Does it now mean that even modifications to existing wiring mean that ALL wiring has to meet the latest regs? Although all circuits are protect by a single RCCB (which as you say in not recommended - is it actually illegal?)

    :D Just though I'd stir it up a little.

    Ah - that makes sense - these are relatively new aren't they? A lot of electrical suppliers/bathroom specialists on the net still have diagrams that refer to the three zones.

    Anyhow, here is a quick diagram of the bathroom. The bath is on a small raised section (only a step high) and the small box on the left hand side of the drawing indicates where I would like the shaver socket to go. Not sure how the zones would be worked out though.
     
  8. ericmark

    ericmark

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    1) A single 100ma RCD was common where a TT (Earth Rod) is used this is no good to protect cables in walls and bathrooms under the new regulations a 30ma RCD is required.
    2) Only if one RCD is likely to trip on a regular basis would it be against the regulations in most houses a 30ma trip would trip but not a 100ma so with 30ma multi RCD are normally required.
    3) The RCD does not have to be before the consumer unit both mini consumer unit type and fused connection unit types.
    There are loads of options
    Eric
     
  9. Spark123

    Spark123

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    Not really - to have all the lights on one RCD isn't a great idea. There are a number of ways of getting around this, having a dual RCD split load board is one method where sockets up and lights down may be on one RCD and sockets down and lights up on the other to minimise inconvenience etc. Another method is to replace the MCBs on the non RCD side of a normal split load CU with RCBOs.
    The current version of the wiring regs which we work to requires certain things to be achieved for safety - one of them is the division of circuits to minimise hazards and inconvenience. A single RCD doesn't achieve this.
    The wiring regs in themselves are not statutory, they can be used to help show compliance with a statutory requirement.
    They superceded the 16th edition back in July. What I mentioned about the division of circuits was a reg back in the 16th too which stretched back to 1991.
    Need dimenstions, but if it is with 600mm from the edge of the bath then zone 2. If it can be splashed for any reason then you may need to reconsider its location.
     
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  11. swinster

    swinster

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    The RCCD in my CU is a single 80A/30ma device.

    Again the main CU and wiring (which include that in the bathroom) is over 15 years old, and whist it may not comply with current regulation, it would have complied with regulations at the time.

    Do I have to change my complete house wiring just to install a shaver socket?
     
  12. swinster

    swinster

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    Does this image show how the room should be zoned correctly?

    If so, are you saying that Dimension "A" should be greater that 600mm?

    I have never noticed any kind of splashing here and should find that this would be difficult - if not impossible. But I suppose this is the for ANY location in the bathroom - even accross the other side of the room.

     
  13. swinster

    swinster

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    Now that's interesting. My basement electrical installation and the main electrical installation in the house were definitely done after 1991. the original was complete as part of a council grant work and both were signed off by the buildings inspector at the time.

    Each CU separate the circuits but both utilise this single RCCD protecting all the circuits (FYI - both RCCDs are 80A/30mA Crabtree devices).

    Are you saying that this is wrong?

    Not sure if this will show anything but here is a photo of the main CU

     
  14. ericmark

    ericmark

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    From what I can see it seems all circuits are protected by a single 30ma RCD as a result I see not problem in wiring the shaver socket as you suggest.
    314.1 Every installation shall be divided into circuits, as necessary, to: (iv) reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced by equipment in normal operation.
    If it's not tripping then it complies simple as that.
    Eric
     
  15. Pensdown

    Pensdown

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    Can I have a glass of whatever you've been drinking :LOL:
     
  16. swinster

    swinster

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    this is why I don't trust electricians. It seem that all of them have different ideas on what is allowed/not allowed.

    BTW - it's not tripping - except when the element in the oven started to breakdown, which is exactly what its supposed to do.
     
  17. ban-all-sheds

    ban-all-sheds

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    Building Control had no interest in electrical work back then - presumably the inspector was just checking that the work had actually been done and the grant could be released.


    Define "wrong".

    Arguably it did not comply with the Wiring Regulations when it was installed, but

    a) they weren't explicit
    b) there was no enforceable obligation to comply with them anyway.
     
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