Discussion in 'Electricians' Talk' started by harmonic, Nov 4, 2011.

  1. harmonic

    harmonic Member

    Had voltage of 110 volt today  customer getting shock of pins in  metal box put temporary earth to consumer unit with long lead and voltage dissapeared no shock,must have lost earth somewere but how is 110 volt present on earth ?
  2. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    "pins in metal box" ?

    Mr. HandyAndy - Really
  3. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Oh dear, lucy.

    I think you are becoming out of favour here more than usual. You are showing yourself to be more unpleasant, obnoxious and pretentious than you have ever been(if that's possible).

    It's very unbecoming, and quite sad to witness.

    Mr. HandyAndy - Really
  4. removed 7

    removed 7 New Member

    Andy dear, that's the nicest thing you've ever said to me sweetheart! Bless you......

  5. madhatter1uk

    madhatter1uk Well-Known Member

    I want to know what this induced voltage is.I seem to remember I had something like this on a 20mm metal conduit with a 6mm T&E for the cooker down it. Conduit had cut through to the neutral, but of course when all the loads were disconnected it wasn't there and when earthed it wasn't there cos it went to earth.
  6. Lokkars Daisy

    Lokkars Daisy New Member

    Perhaps JP would be kind enough to elucidate
  7. removed 7

    removed 7 New Member

    Go to bed you silly man!

    If anyone is still interested in this sad thread. tomms - I'll be pleased to explain it in a polite and clear way. What a load of rubbish has been spouted here!

  8. J.P.

    J.P. New Member

    One the pre-supposition that the metal conduit had a patent earth - how could you have got an induced voltage on the conduit Hat despite cut neutral and other stuff you mention? - surely no PD could arise on a properly earthed steel conduit which has patent earth continuity throughout its whole length?
  9. J.P.

    J.P. New Member

    We are talking a patent supply Lucia, and not an intermittently malfunctioning PME supply..;)
  10. removed 7

    removed 7 New Member

    More than 1050 views on this thread, but fewer than a dozen posts (or so it seems)..........

    Someone's been deleting again, haven't they, Johhny?

  11. Lokkars Daisy

    Lokkars Daisy New Member

    wwtf is this patent stuff , please tell
  12. J.P.

    J.P. New Member

  13. madhatter1uk

    madhatter1uk Well-Known Member

    Its shiny leather I believe Lokkars. miss summers and westward bound are good suppliers of it so i'm told
  14. Crazy Eddie

    Crazy Eddie New Member

    Long time no speak Screwies.

    I presume this post may have been answered and deleted by the phantom post editor, but just in case, my Merlot has incited me to reply.

    If 110V, or more often half the nominal supply potential is present on the CPC, it usually appears from filter circuits / functional earths / and the like when there is a bad earth. Hence it went when you earthed the offending article.

    Electronic kit often has filter circuits with caps from L to E, and From N to E.  Take away the earth and the other side floats to near mid the supply V.  Can be easily observed by checking the potential on the metal case of a PC plugged in via an extenstion lead with a dodgy earth. Was common in the old days and made the old green screens wobble too.  The same effect at a lower level is observed with class II gear when you plug a USB or the like from one device to another, there is a little finger tingle or a baby spark as they swap electrons and 'agree' a new potential to float at.

    There shouldn't be more than single digit mA's even with mains, and if there is you need high intergrity earthing, etc.  In your situ I would check the current that flows when you connect the new CPC. It can easily be the case that a few amps are flowing if there are serious earthing issues. High juice may reveal in a high impedance connection where the continuity tester says it is OK.

    One day I will learn to do short posts.

  15. 200arty

    200arty New Member

    I had the same sort of problem some years ago it turned out there was moisture in the grill element of a microwave
    ofen I was repairing. Gave slight tingle on skin and read low resistance on a meggar. New element did Trick.
    Suggest turn of all appliances.Then turning them on one at a time to see if leaking voltage disappears and re appears.
    Retd. Microwave/TV Engineer
  16. Lectrician

    Lectrician Screwfix Select

    If a property or circuit has no, or a high impedance earth, any leakage will cause a voltage to appear on the earth.

    If you received tingles while repairing the apparatus, it should have signalled to you that there was an issue with the earthing that also needed to be sorted.

    If the earthing was in place, you would not have recieved any tingles.

    Rather than trying to find which piece of equipment is "leaking", you should sort the earthing issue.

    "A new element did the trick" - I expect it did, but also hope you sorted, or informed the customer of the earthing fault.
  17. Lokkars Daisy

    Lokkars Daisy New Member

    *** lectrician, remind me of Maria out of the Sound of Music ,,,the movie,,, you'll be making tool bags for me and Lucia out of the curtains next
  18. madhatter1uk

    madhatter1uk Well-Known Member

    I told the customer they needed a rewire and a new cooker.
    Which they did.
    What I couldn't get was how the heck the managed to force a 6mm twin and earth down a 20mm steel conduit with razor sharp end. 
  19. J.P.

    J.P. New Member

  20. J.P.

    J.P. New Member


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