cable for mains spur

Discussion in 'DIY Discussion' started by taz, Apr 27, 2006.

  1. taz

    taz

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    taz, Apr 27, 2006
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  2. taz

    penance Arrogant Cock

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    I would stick to twin and earth.
     
    penance, Apr 27, 2006
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  3. taz

    zanash

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    If I'm not mistaken this cable has a steel "screen" or armour in this case. Look for CY cable or use twin and earth as suggested.
     
    zanash, Apr 27, 2006
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  4. taz

    granville

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    I don't see why not, as long as you can fit the 4.00mm conductors into the back of the sockets you are using.
     
    granville, Apr 27, 2006
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  5. taz

    3DSonics away working hard on "it"

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    Hi,

    The cable you note is a reasonable choice, HOWEVER, consider solid core versions of it. Also, copper piping for plumbing make great screening ducting for a spur using solid core cable.....

    Ciao T
     
    3DSonics, Apr 27, 2006
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  6. taz

    taz

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    i haven't seen a solid core version but what i was thinking is the power rating ie 500v and 30amps when connected to a 20 amp mains unit trip. Also this cable is designed/used for mains electric in the first place
     
    taz, Apr 27, 2006
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  7. taz

    felix part-time Horta

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    True, but not necessarily for fixed installation. That current rating will be for use as a flex, ie non-fixed in open air, and you'd have to do some calcs to show it would still be safe when in conduit/buried in the wall, where the temperature will rise. BS7671 governs UK mains installations; though at £96 you're unlikely to want to buy a copy!
    It might be worth browsing the IEE forums for help / guidance.

    Bear in mind new work needs to comply with Building Regs Part P - and so a [inew spur installation will require a building notice and local authority inspection or installation by an approved/accredited electrician...

    F
    (not an electrician!)
     
    felix, Apr 27, 2006
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  8. taz

    granville

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    The cable is upon inspection 5 core. It is therefore for 3 phase installations, hence 30 amp at 500 V. 3 phase uses 3 live conductors at 416 V + neutral and earth. It also explains the steel braiding. What are you going to do with the two spare conductors :confused: This cable is way over spec for a spur for a domestic hi-fi; unless you have the mother of all power amps :D
    along with the worlds most ineficient speakers.
     
    granville, Apr 27, 2006
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  9. taz

    de'Kev

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    Not the sort of cable that's ideal for this application. It's designed for wiring applications where movement or vibration is expected and needs to be wired into metal boxes using glands. You wouldn't wire this into your consumer unit unless it's metal, very unlikely, and you would really need a metal socket otherwise you can't gland it off.

    Felix makes a valid point, this cable isn't designed for burying it's meant for free air applications, if you bury it you will have to derate it's current capacity.

    Do you need 5 cores?
    If not just use 2.5 T&E, if you're worried about the cable acting as an aerial then run it in an earthed metal conduit.

    Felix, doesn't part P apply only to bathrooms and kitchens and adding a spur to an existing supply is exempt from buiding regs approval?

    Kev
     
    de'Kev, Apr 27, 2006
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  10. taz

    felix part-time Horta

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    Sorry, no, it applies throughout domestic installations - unless you're replacing damaged existing work. Exemptions are listed in Table 1:

    [​IMG]
     
    felix, Apr 27, 2006
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  11. taz

    de'Kev

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    THat's OK then, he's adding a fused spur to an existing ring :cowboy:

    :D
    Kev
     
    de'Kev, Apr 27, 2006
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  12. taz

    felix part-time Horta

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    That's the way I'd look at it - and make sure its from a socket very close to the CU if poss ;)

    The stupid thing is - this is exactly the area of danger-from-uninformed-DIY that Part P was intended to prevent!
     
    felix, Apr 27, 2006
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  13. taz

    Sid and Coke

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    If you must use screened cable why dont you use Armoured steel cable, the type that you find in factories, or for running a spur out to a garage etc. You will still need to use glands and metalclad sockets, etc.

    Why are you fitting a seperate spur ?

    I fitted mine a few years ago now to try and solve a particular mains noise problem that i had (and still have however it is now masked), the dedicted mains spur didn't solve the problem.
     
    Sid and Coke, Apr 27, 2006
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  14. taz

    3DSonics away working hard on "it"

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    Hi,

    Not to put too fine a point on it. I'm very much in favour of true electrical safety, but on the subject of current regulation I would submit the following corollary written by a great british patriot:

    "A free people ought not only to be armed and disciplined but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government."

    George Washington

    And yes, GW was a Briton, NOT an American.....

    Ciao T

    PS:

    [​IMG]
     
    3DSonics, Apr 28, 2006
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  15. taz

    felix part-time Horta

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    Totally agree!
     
    felix, Apr 28, 2006
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  16. taz

    taz

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    ok
    there are pro's and con's of fitting a dedicated mains spur for hifi
    and those who are for it and against it, I have been messing with hifi for over 24 years and the 3 places I have lived all benefited from a separate mains connection. Although I'm not a qualified spark I do have some experience around electricity (overhead linesman for 15 years) and my farther was probably the finest switchgear electrical engineer of his time.
    in the past i have always used t&e as per code but in our present house i installed a spur 10mm t & e but the problem although slightly reduced was still there.
    I was only thinking out loud so to speak as to whether a shielded mains cable would work better and if so where i could source some cable without paying ridiculous prices.
    safety however is paramount and I'm no cowboy or fool but i do believe good mains is important.after i had treated the mains in my last house you could select any source on my amp and turn the volume to max with no noise at the speakers at all even with your ear 2" away from the drivers, so I know it makes a difference (before you could hear a 50hz hum). my mains runs under the floor in a void so no need to bury cable in anything
    thanks chaps
     
    taz, Apr 28, 2006
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  17. taz

    taz

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    ok fully sorted now
    i used a seperate consumer unit and 2x 2.5 twin and earth wrapped together with foil shield/tape with a dedicated earth
    sounds better/quieter no more mains hum:D so well happy
     
    taz, May 3, 2006
    #17
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