Blanking off knockouts on Consumer Unit

[williamglossop]

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......

 

[RF Lighting]

If they are round holes, use blanking plugs and lock nuts

 

[333rocky333]

Metal ones i think look neater with a Lockring each side.

They now make fireproof cable entry grommets, though really designed for cable entry, i guess can be used as blanks.


https://www.cef.co.uk/catalogue/products/4352169-fire-retardant-membrane-cable-entry-kit-1

 

[ban-all-sheds]

Why a lock ring each side?

 

[JohnD]

avoids unsightly paint scrapeage?

 

[333rocky333]

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

 

[SimonH2]

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.

 

[ban-all-sheds]

Good point.

 

[SUNRAY]

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.

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.

 

[ban-all-sheds]

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.

Aren't washers quicker, simpler, and cheaper?

 

[ban-all-sheds]

They now make fireproof cable entry grommets, though really designed for cable entry, i guess can be used as blanks.


https://www.cef.co.uk/catalogue/products/4352169-fire-retardant-membrane-cable-entry-kit-1

They are fire retardant...

 

[rsgaz]

Aren't washers quicker, simpler, and cheaper?

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

 

[SUNRAY]

Aren't washers quicker, simpler, and cheaper?

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.

 

[JohnD]

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.

 

[ban-all-sheds]

..and for the unit to remain amendment 3 compliant? Assuming of course, its an amendment 3 compliant board to begin with......

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