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Replacing a PIR floodlight - best practice

Discussion in 'Electrics UK' started by Flinstone, 23 Mar 2021.

  1. Flinstone

    Flinstone

    Joined:
    2 May 2004
    Messages:
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    Location:
    Devon
    Country:
    United Kingdom
    I want to replace a faulty conventional PIR floodlight with a new 20W LED version.

    The current install uses approx 2.5-3mtrs of T&E white PVC which routes from a FCU in the kitchen along and up the kitchen wall in plastic mini trunking. It then exits above the kitchen back door through a hole in a cavity wall, followed by a 250mm loop to the floodlight which is mounted on its metal tilting bracket just below the cable exit point on the wall.

    I think the install is below par in two respects,
    1. Using white PVC cable the external looped section is vulnerable to UV and being T&E it has a poor appearance that shows up any kinks in it; so it looks poor compared to say round black flex.
    2. The cable does not have any protection where it passes through the cavity.

    So is it a good idea to do the following?
    Replace the complete length of T&E (inside & out) with black rubber sheathed 3183P to gain improved UV protection and aesthetics (an alternative is to terminate the existing PVC in a new junction box then off to the new floodlight via a short length of black flex but this adds more components to potentially fail)?
    There is no reason why flexible cable can't be permanently installed in the kitchen is there? Will it meet regs if it's enclosed in the original trunking?

    The aforementioned 3183P cable is 6.6mm OD. I would like to use some old 15mm plastic water pipe (ID approx 12mm). Is this the appropriate size an electrician might use?

    Where should any sealing be done> some silicone around the pipe prior to placement? But how about the cable within the pipe. Do the professionals stuff plenty of silicone INSIDE the pipe too (at both ends) or, from a maintenance/future withdrawal point of view, is a putty or similar used?

    Thanks for any experienced advice on this. I know it should be pretty simple but I'd like to do it properly.

    Cheers
    Flinstone
     
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  3. Adam_151

    Adam_151

    Joined:
    17 Jun 2004
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    Just put a wiska box over where the cable exits, and then take a flex out the bottom to light via stuffing gland, 90% of lights you buy now come with a short lnegth of flex pre-wired anyway.

    Put a dab of silicon or compound in the hole where the cable enters the back of the box.

    Don't worry too much about an insulated and sheathed cable passing through brickwork, I've never seen it cause any damage, unless its pulled tightly around a corner etc. Its often a spec'd requirement on some jobs to sleeve through walls but I really wouldnt worry about it in this instance
     
  4. DIYnot Local

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    3 Sep 2019
    Country:
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