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Blanking off knockouts on Consumer Unit

Discussion in 'Electrics UK' started by williamglossop, 23 Dec 2018.

  1. williamglossop

    williamglossop

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    Is there an acceptable way to blank off knockouts on a consumer unit that have been knocked out but that are no longer in use, and for the unit to remain amendment 3 compliant? Assuming of course, its an amendment 3 compliant board to begin with......
     
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  3. RF Lighting

    RF Lighting

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    If they are round holes, use blanking plugs and lock nuts
     
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  4. 333rocky333

    333rocky333

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  5. ban-all-sheds

    ban-all-sheds

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    Why a lock ring each side?
     
  6. JohnD

    JohnD

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    avoids unsightly paint scrapeage?
     
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  7. 333rocky333

    333rocky333

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    Cosmetics really, bushes etc seem so sloppy nowadays in the hole, as well as what John says but i guess that can be avoided by not turning the Head and just turning the lockring
     
  8. SimonH2

    SimonH2

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    There tends to be gaps between the flats of the head and the hole it's in - with the plug only held by the corners. A lockring would be like putting a close fitting washer on so it would look neater.
     
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  9. ban-all-sheds

    ban-all-sheds

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    Good point.
     
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  11. SUNRAY

    SUNRAY

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    I find the flats are getting smaller and smaller, to the situation where sometimes one or two points will drop into the hole, so yes I too have been fitting two lockrings for years on all sorts of hex headed fittings.
    Also some people seem to make big holes with their starretts by wiggling the drill around and I often find I have to do something similar for couplers.
     
  12. ban-all-sheds

    ban-all-sheds

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    Aren't washers quicker, simpler, and cheaper?
     
  13. ban-all-sheds

    ban-all-sheds

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  14. rsgaz

    rsgaz

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    A 'normal' M20 washer would have a diameter of 37mm, so that doesn't work with closely spaced holes or ones near an edge. So, no, lockrings are cheaper and much more readily available. (unless you had a different type of washer in mind?)

    You'd need something with an OD of about 25mm for that to work, at much higher cost...
    https://www.ffx.co.uk/tools/product/Trend-Bw4-5027654016145-20Mm-Bore-Bushing-Washer-25Mm-Diameter
     
  15. SUNRAY

    SUNRAY

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    Not in my opinion for several reasons:
    Quicker & simpler, possibly but spinning a lockring onto a fitting takes 2 seconds. Edit: and as a bonus it pretests the thread before trying to fit in a fiddly position.
    Cheaper? Depending on POS washers may be dearer.

    The size of the hole in a standard M20 washer is frequently close to 21mm so it does not actually solve the problem.
    M20 washers are around 35mm diameter and frequently far too big to fit in the available space.

    The number of lock rings used far outweighs the number of washers so all in all there is no real benefit to carrying an additional item.

    Edit: Sorry didn't see rsgaz's reply before I replied.
     
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  16. JohnD

    JohnD

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    if you look for "form C" washers, they have a relatively large external diameter, so useful on sheet metal and soft wood.

    Ordinary washers are "form A" and rather small, just enough for an ordinary screw head or nut. If you buy them by the hundred there is not much price difference.

    https://www.ebay.co.uk/itm/M4-M5-M6...a0d5905a0:m:m4WOtk-ktqgQ8rTqSZk4Uyw:rk:2:pf:0

    https://www.ebay.co.uk/itm/A4-STAIN...HhszN1mpv6pGmFhUlQ:rk:3:pf:0&var=420737342367

    You could also use flanged nuts on the inside, so no washer needed
    https://www.ebay.co.uk/itm/M4-M5-M6...a0d5905a0:m:m4WOtk-ktqgQ8rTqSZk4Uyw:rk:2:pf:0

    For some reason, flanged or button-headed screws are more expensive.
     
    Last edited: 28 Dec 2018
  17. ban-all-sheds

    ban-all-sheds

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    Or push-in plastic blanks - the infamous non-flammable requirement does not apply to subsequent modifications.
     
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