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100mA RCD in CU

Discussion in 'Electrics UK' started by conny, 3 Sep 2020.

  1. conny

    conny

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    Often read the threads on here and there is often talk about 30mA RCD's for protection.

    I am in rented property and have an EICR booked by the landlord for mid October. Just had a look at the CU and the main isolator is a 100mA RCD with 9 separate circuits, (2 still wired but no longer used), all protected by MCB's of varying current rating, (2 x 5A for lights, 2 x 30A for sockets, 1 x 45A for cooker, 1 x 15A for defunct storage heaters, 1 x 15A for defunct water heater, 1 32A for ring in new part of house and 1 x 6A for lights in new part).

    When the test is done is it likely they will recommend the RCD is changed for a 30mA one or is it still ok to use the 100mA unit? There is no other RCD protection for any of the circuits but some individual appliances that belong to us have RCD fitted plugs. The CU is a plastic Crabtree housed behind an MDF panel at the top of the wall upstairs. I seem to recall a guy who came about 5 years ago saying it was TN-C-S but could be wrong as we can't see where the main cable enters the property.
     
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  3. chivers67

    chivers67

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    The Sockets ideally should be protected with 30mA especially if serving anything being used outside. Depending on the type of Crabtree an RCBO or RCD could be fitted inside the DB as it's not ideal to have the whole property protected by a single RCD is it Time Delayed ?
     
  4. conny

    conny

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    We have a 30mA outdoor RCD socket spurred of the lounge ring. It's only ever used for a small electric mower or strimmer. As for it being time delayed I have no idea. What information on the RCD would I be looking for?
     
  5. chivers67

    chivers67

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    Can you Post a photo of the Board?
     
  6. conny

    conny

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    Will try to get one later. Prepping for my wife's birthady tomorrow at the moment and family just arrived.
     
  7. AndyPRK

    AndyPRK

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    Time delayed RCD are marked S
     
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  9. conny

    conny

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    Just took these shots. As you can see, the cupboard is quite tight so he/she is going to have some fun with that.
    Can't see S on the RCD/isolator.
    Ignore the labels underneath, I have drawn up a separate sheet with current markings and stuck to inside of cupboard door.
    Just noticed when I loaded the pictures it's actually an ELCB not a 'modern' RCD. I imagine that will be a recommendation for changing.
    I can't get a photo of the head to see what the incoming actually is but reckon with a torch the sparkie should be able to.

    P1030479.JPG P1030480.JPG P1030481.JPG P1030482.JPG
     
  10. fluorescence

    fluorescence

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    It is a current operated elcb so is an RCD
     
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  11. flameport

    flameport

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    Not time delayed, and there is no possibility of RCBOs for that consumer unit, or changing the existing RCD to a 30mA.
    For that to comply with BS7671 now, it's a new consumer unit.
     
  12. Taylortwocities

    Taylortwocities

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    Frankly, As you are the tenant, none of this is your problem!
    Situation is as Flameport says, above.

    Your photo shows one of my pet hates: boxing in that prevents any form of maintenance.
    it looks like that the electrician who is doing the EICR will be unable to remove the front of the consumer unit! He/she will need access to the internal wiring to inspect and to do any testing.
    It will certainly need some wood panel removal to do this, and should a new consumer unit be required.
    I would have your landlord check this out before the EICR or the electrician will be charging for two visits.
     
  13. ericmark

    ericmark

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    The RCD will get at least a code C3, but the landlord does not need to act on a C3, what is the problem is if the inspector gives it a C2 which means 28 days to correct, it is not cut and dried what should be awarded, C2 means potentially dangerous and personally I would say it is not potentially dangerous.

    It is made in a 30 mA version, however with all on one 30 mA I would expect some nuisance tripping, and if it trips you loose all, no way to run essential circuits from another supply, so a nice new consumer unit would be nice, but you don't want the 100 mA swapping for a 30 mA, and it would be better if you and landlord can select a time to upgrade, not be forced to do it in 28 days, so I would hope for a C3, so you have time to discuss when any upgrades, if any are made.
     
  14. ericmark

    ericmark

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    Well spotted, how anyone would even read the DNO fuse I don't know, yes that will need removing.
     
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