Cable support requirements in 18th edition

Dec 15, 2020 Last reply: 5 years ago 9 Replies
C

In the DIY FAQ it says:-



There are new requirements for all wiring support to not fail as a result of fire (i.e. this no longer just in escape routes). So cables supported in plastic trunking or in plastic conduit will also need additional metal clips.



Does this mean that metal clips are required in *all* plastic trunking or only where the wire can fall out? I.e. does trunking running along the floor or on a rafter/ceiling require metal clips?



It does make using trunking a bit of a pain and self-adhesive trunking becomes pretty useless as you still have to knock nails or screw screws through it.



Apart from the D-Line clips no one seems to be producing hardware to provide this cable support, are there any well thought out systems available that provide the required support, are easy to install and look reasonable?


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B

I recently installed a length of SWA outdoors. I cut short sections of steel band and moulded them inside the cleat - and then put the fixing screw through the whole lot. Not all of them, just at sufficient intervals to prevent it causing problems in a fire. Got the idea of doing that from another forum. My point being that I couldn't find any other good way of doing it. Haven't got round to all the indoor cabling that needs doing, but all I've seen so far is some rather pricey cable clips -

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- I presume that if a cable runs through the middle of a joist it doesn't need protecting (what would you clip it to if the joist is burned through!). Similarly running a cable in a vertical chase seems pretty low risk. If people think differently, then I'm surprised there isn't more choice of protection available.

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R

metal cable cleats for SWA? Eg

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J

Anywhere that failure of the support from the trunking could cause an entanglement hazard...

So that would be vertical horizontal runs on walls or overhead certainly. IMO whether that also applies on floors will depend on circumstances.

Lots of places seem to have:

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A demo of how these are used here:

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TLC carry:

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C

They're OK but have the same problem as anything else mounted inside the conduit, you have to drill and fix the clip before putting the cables in. The above do have the significant advantage of making it fairly easy (by the look of it) to get cables in and out after fixing the clip.

Also, can you get them for all sizes of mini-trunking, in particular the small sizes.

Yes, they're the ones I referred to, lots of people sell them but it's not very clear how they work.

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C

They seem quite expensive too:-

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T

The D line trunking clips are fine but you need to use the correct trunking, for instance Tower trunking is incompatible as it has a ridge down the centre to enable a divider to be clipped on just where the screw needs to go. I made the mistake of using it and ended splitting the D line clips and used two screws instead of one it was a real PITA.

RICHARD

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B

The problem when I hear this sort of thing is that cables are mostly insulated by pvc, so what is the point anyway? The moment the pace melts, the conductors shour out and kill the power, surely? Brian

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C

But, the wires are still there. A fireman got trapped by drooping wires and died.

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J

Its nothing to do with shock risk, just entanglement risk.

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