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Moving Wooden Blocked Light Switches.

Discussion in 'Electrics UK' started by CAWORK, 24 Jul 2020.

  1. CAWORK

    CAWORK

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    Hello Everyone

    A chap who lives down the road from me has suggested he wishes to move some light switches in his house.

    I would like some clarification of the following please (although I'm fairly sure you will all agree with most if not all, of what follows).

    The light switches are of the brown Bakelite circular type mounted on wooden blocks (He even has one mounted shoulder height, right above the bottom end of the bath!!!!).

    He has lived in the house 30 years, but of course, I for one am fully aware the wiring/switches are probably at least twice this age. Not sure if the switch covers are screw fitted or screw on (if the latter, removable without the the use of a tool and therefore I imagine, cannot be put back into service once removed from the wall).

    Since he wishes to move the switches, this would invariably mean having to use new switches, since the wooden blocks are no longer permitted? A lighting system of this age is extremely unlikely to have a CPC, so he certainly cannot use metal switches (though he hasn't actually suggested this).

    It is highly likely to be wired in rubber, cloth etc, which may disintegrate upon handling it from removing switches. Even if the insulation and/or sheathing is intact, to move the switches would almost certainly require extension of the existing wiring with additional cables, and even if plastic fittings were to be used, there would be nowhere for the CPC in the new cables to be connected to on the existing circuit(s). I am aware all plastic fittings do not actually require a CPC, I would imagine it though to be considered as 'bad practice' to extend off an existing circuit such as above with new cable with CPC (especially as in many, many years down the line someone may replace the plastic fittings with metal and 'assume' there is a CPC in all of the existing circuit.

    Although he hasn't stated whether any new cabling will be surface run or concealed, if the latter then the RCD issue raises it's head.

    The cables might be run in conduit, which will be difficult to cut etc. What about the scenario if a switch is moved to a position which happens to be the direction the cables are run from and are not in conduit, are in good condition and therefore just need shortening?

    ( I gather the existing switches and wooden blocks still cannot be re-used?).

    I have only been in the house a couple of times, but vaguely recall seeing a Wylex Standard CU (probably wooden backed), so quite old, although quite likely not as old as the lighting circuits switches etc. Probably no RCD protection anywhere.


    Kind Regards
     
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  3. securespark

    securespark

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    I wouldn't like to touch old rubber cable.

    At that age it will most probably be extremely friable.

    I would kindly suggest to the fella that his wiring has had a good run for its money but now he should rewire.
     
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  4. conny

    conny

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    Rewire without a doubt. Hate to think what the cables behind may be like. My experience of rubber cables, many years ago, was they crumble as soon as you look at them.
     
  5. Colin Brenton

    Colin Brenton

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    Yep, time to rewire (assuming they genuinely ARE old switches, and not reproduction old looking ones!)

    My 1955 built house had rubber insulated cable when I bought it, and the insulation dropped off the cores when you flexed them to put them into a terminal.

    Full rewire was the only remotely sensible fix, especially as there were only one or two single sockets per room and no earth on the lights.
     
  6. CAWORK

    CAWORK

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    Good Afternoon

    I kind of guessed this is what the advice would be.

    I don't know for ABSOLUTE SURE what the cables would be made from, since when my parents cottage first had electricity installed in 1960ish, brown round switches with unscrewable covers were installed, and after rewiring, one switch was left in place behind a cupboard for many years after.
    Upon finally removing it, it was fed from two single core PVC singles (red insulated, L & SWL).
    But I had thought if that even if that is the case here, then extending any wiring with T&E, there will still be no place for the CPC to be connected to on the existing circuit(s), (even if plain plastic switches are used, bad practice?).

    Regarding rewiring, the chap asked me, and and claimed to have asked a local Electrician, 'What age does your wiring require replacement'?
    (I know opinions vary on this, and I understand there isn't actually an officially accepted/recommended age).

    Personally though, I would imagine there is a VERY HIGH chance the wiring will be rubber, cloth etc judging from the style of switches.

    EDIT: They ARE genuinely old ones, since he has lived in the house 30 years and were there when he moved in, but like I first said must be at least twice that age.

    Regards
     
    Last edited: 24 Jul 2020
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  8. conny

    conny

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    Unless you are a qualified spark that can rewire, fully test and issue certificates, I would advise to stay well clear and tell him he needs a professional to come in and do whats necessary.
     
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  9. flameport

    flameport

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    Regardless of what type of cable exists, any alterations will require an RCD installing - all lighting circuits in dwellings require RCD protection now.

    If the cable is rubber, it should have been replaced decades ago. Moving any of it, even just to have a look at the terminations at a switch is something to be avoided.

    PVC cable may be usable, but even there it will be at the end of it's useful life. No CPC isn't compliant for any new or altered parts, and there is still the requirement for RCD(s).

    Old switches can be used in some circumstances, but they would need to be of the type that can't be opened without a tool, or modified to secure the cover. Wooden mounting blocks can also be used, but any terminations / connections and single insulated cables cannot be directly contained in the wooden parts. Modifications are possible but will likely cost more than just buying modern reproductions.
     
  10. Harry Bloomfield

    Harry Bloomfield

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    The bakelite switches with two screws holding the cover, were common in the 1940's /50's. Buried in the wall, might be 5/8" grip conduit and VRI (waxed cotton covered rubber), or TRS (tough rubber sheathed) a similar format to modern PVC, unlikely but possible lead sheathed cable (like the TRS, but with a thin top coat of lead). All were to Imperial size standards, so 1/044 or maybe 3/029 for the lighting circuits, 7/029 for 13amp sockets.

    The grip conduit was usually only installed when it was installed as the house was being built. I don't know if it still acceptable, but when rewiring where there is grip conduit in the walls, it was sometimes possible to knock the T off at the top and reuse the conduit drop down the wall to avoid replastering.

    What ever is in there, it needs to be rewired as a matter of urgency and brought up to standard.
     
  11. CAWORK

    CAWORK

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    I am fully aware of that. He hasn't actually asked me to do any of the work. He is a handyman/odd job type bloke himself but one of the types that won't do electrics (fair play!).
    He did ask if I thought it would be POSSIBLE for the switches to be relocated and my thoughts, but I made VERY clear I am not willing to touch it myself.

    However I did explain the situation regarding the wiring itself to him (explaining much of what is mentioned above) and that it will most probably be a very unlikely case of simply cutting back or extending cables as could/would often be done in a modern system.

    Regards
     
    Last edited: 3 Aug 2020
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