Terminating SWA in a Consumer Unit

Discussion in 'Electrics UK' started by elfreddo, 22 Nov 2004.

  1. elfreddo

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    Thoughts Please,
    I'm about to install a 20A radial circuit to an supply an extension.
    For the ease of installation the feed will come directly from the CU and be run though the garage wall in 2.5mm 3 core swa to a plastic termination box (ip56) on the extension wall. From here the it will be terminated using 2.5 T&E to feed the necessary power outlets inside.
    My query is what is the best way to terminate the SWA to take the tails in the CU.
    Cheers
     
  2. dw3101

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    You sound like you dont know what you are doing and the cable sizes dont sound correct.

    If you are adding an additional consumer unit I would use larger cable circa 10 - 16mm. You can terminate the gland directly into a metal clad consumer unit.

    The other end should be terminated into a metal clad switch fuse which you can then run the tails from, or teminate into an adaptable box and then run 10mm T&E or similar to the existing consumer unit.

    David
     
  3. elfreddo

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    Let me explain further,
    The power for the extension will be supplied from a spare 20A mcb in the existing cu (in the garage) This will then be run in the form of a radial. Because the cable has got to go outside for 5 meters then back into the extension I was going to use SWA instead of 2.5 t&e run in conduit.
    Should i terminate the swa in a plastic or metal adapable box and how?
    Cheers
     
  4. ban-all-sheds

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    Yes, as you'll find it very hard to teminate it directly in the CU, they are usually too crowded. And, if plastic, too flimsy. So use a box - metal is best.

    With a SWA gland, of course, just as you would have done if you were terminating it in the CU....
     
  5. Paul_C

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    A galvanized or black enamel 3 x 3" adaptable box with 20mm knockouts is ideal for this purpose. You can terminate the SWA with a 20mm gland into the box, then run T&E to it from the panel.
     
  6. securespark

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    What I do with insulated CU's is as follows:

    I terminate the SWA into a galv through box, making sure the tails are plenty long enough to reach the CU terminals required.

    Then I fix the through box to the CU: Having drilled a suitable hole, I fix the galv box to the cu with a bush. All that then remains is to wire the conductors up to the CU and run an earth tag to the galv box, not forgetting a lid!

    I prefer this method, especially for larger circuits, as you don't have to join T & E to the SWA (another unwanted junction).

    Of course, some CU's are not suitable for this method, as you cannot remove the lid once the galv box is fixed.......
     
  7. ban-all-sheds

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    Use a bit of conduit instead of a bush?

    If you use the flexible stuff you'd have complete freedom regarding the relative positions of box & CU.

    Note to anyone reading this thread - this technique is for 3-core SWA, not 2....
     
  8. plugwash

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    also depending on how long this run is you might want to run something a bit bigger than 2.5mm
     

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