RCD Protection

  1. steviec_lj

    steviec_lj Rust Welding Professional

    Messages:
    2,801
    Location:
    Barnetby, N.Lincs
    Had an EICR done a couple of weeks back, the “house” passed and there were no issues with it.

    The feed to the workshops, and the workshops however failed.

    All wired in single core 6491X is used throughout in both workshops, the garage, and both storage sheds. Workshops and garage were installed on cable tray as it was quick, easy, and more importantly in stock at Cavill Towers.

    The tray has now been swapped out for some plastic trunking, which looks dog eggs in my eyes, but if that’s what it takes to pass then that’s enough, I’d have used steel and bonded it but couldn’t get enough from the local suppliers.

    Now, I need to install some RCD protection. Sparky says it can be in the Fused Switch in the kitchen where the supply comes from, or, on each supply in the garage. Supplies to all buildings is in XLPE SWA buried or suspended depending on which building it goes to.

    Question;
    Can I install the RCDs in each building, rather that the “main” feed to save the walk of shame?

    Or do the need to be protected at source?


    Quick run down is;

    100a Fused Switch fed by 25mm tails direct from the main incomes. Goes out on 16mm SWA to,

    12 way DB containing 5no 100a main switches, which the goes to,

    DB2 fed by 16mm SWA to supply the garage.
    DB3 fed by 10mm SWA to supply Shed 1
    DB4 fed by 6mm SWA to supply Shed 2
    DB5 fed by 16mm SWA to supply the Workshop
    DB6 fed by 16mm SWA to supply the Workshop

    Don’t fancy a 50-75mtr walk to reset an RCD, so thought was to put them in each board?

    Cheera
     
  2. dobbslc

    dobbslc Forum Supporter

    Messages:
    5,734
    Location:
    Hertfordshire UK
    Yikes single core on tray!
    The RCD's can be in each shed but will all be rated at 30ma, I'd say the supply cable needs protecting with a 30ma RCD too! The problem with that is a fault in one shed will still trip the whole supply out so you'reback to the wall of shame!
    You can get time delayed RCD's (S type) and fit a 100ma one at the mains, this might get you round the problems.
    One thing I'd be checking though is the 16mm SWA cables buried in the ground with a 100A fuse supplying them.
     
    brightspark likes this.
  3. brightspark

    brightspark Member

    Messages:
    31,683
    Location:
    yarm stockton on tees
    yep time delayed 100 ma at source for protecting the cable 30 ma in the buildings . as above 100 amp is too high for 16 mm feed needs lowering
     
    Hopefuldave, dobbslc and mtt.tr like this.
  4. steviec_lj

    steviec_lj Rust Welding Professional

    Messages:
    2,801
    Location:
    Barnetby, N.Lincs
    Singles on a cable tray was supposed to be a temporary install, as that’s what we had in to get power sorted for incoming jobs. I hang my head in shame.

    100a on the 16mm SWA may be wrong, they could be 63a switches in all honesty.

    100ma S type at the fused switch?

    The 12 way DB populated with main switches can be left as is?

    30ma AC type in easy building?

    Just putting together a list for Edys in the morning, before assessing damage caused over the weekend.

    Thanks
     
    brightspark likes this.
  5. dobbslc

    dobbslc Forum Supporter

    Messages:
    5,734
    Location:
    Hertfordshire UK
     
    steviec_lj likes this.
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