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All Neutrals are showing live on my tester even when off

Discussion in 'Electrics UK' started by bonkersbill, 10 Jul 2012.

  1. bonkersbill

    bonkersbill

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    Hi all, ive been crawling about in my loft on boards that i layed on top of the insulation doing some plumbing when my upstairs lights went out, ive checked that i have lives to my switches but the neutrals are also showing live on my screwdriver electric tester, all but one of the lights are also live at both neutral and live whether the switch is on or off. Is this a live wire that has touched a neutral somewhere and if so is there a way of tracking it down?
     
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  3. ban-all-sheds

    ban-all-sheds

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    Throw that screwdriver away, and get a proper 2-pole tester.

    If a L&N had touched then the MCB would have tripped.

    Chances are you've broken the neutral in the lighting circuit somewhere.

    Before taking up the boards and insulation, check in all the light fittings.
     
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  4. chapeau

    chapeau

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    This can happen in older houses that have what's called a 'borrowed neutral' which means your downstairs and upstairs lighting circuits might be connected. They are tricky to track down, turn off both circuits and see if it is still showing a voltage. If you have RCD's in your fusebox then it won't be that, and if you do have a borrowed neutral you will not be able to install RCDs without a rewire. You also need to find out why the lights went out, sounds like you might have broken something.
     
  5. bonkersbill

    bonkersbill

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    I forgot i had a multi meter, tracked it back to just what you said Ban all sheds, a loose neutral, cheers for all suggestions.
     
  6. ban-all-sheds

    ban-all-sheds

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    Unless you find it in the first place you look, which is the landing light, where you'll find it 99.99% of the time.


    If both up and down circuits are on the same RCD, what will happen?
     
  7. securespark

    securespark

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    Nothing untoward, except perhaps non-compliance with the regs concerned with separation of circuits.
     
  8. ban-all-sheds

    ban-all-sheds

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    When I made that post, I wasn't aware that chapeau had put me on ignore, and therefore wouldn't see it.

    Which means, of course that from his perspective he wrote

    "If you have RCD's in your fusebox then it won't be that, and if you do have a borrowed neutral you will not be able to install RCDs without a rewire"

    and didn't see anything to counter it.

    Like I said,
     
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