AC on mains but no voltage?

Discussion in 'General Electronics Chat' started by jaco_boon, Jun 22, 2016.

  1. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
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    Hi!
    I'm new to this forum, so sorry to just jump in here(don't know how to get around yet)
    I've got situation where I get AC ons my mains supply of domestic 220V single phase installation but there is no voltage...
    HOW IS THIS POSSIBLE?
     
  2. paulktreg

    Distinguished Member

    Jun 2, 2008
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    Don't know what you're asking here?

    More information please.
     
  3. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
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    I've switched off all breakers on main panel except for main breaker.(0Volts on volt meter)
    When switching on earth leakage (102V)
    When switching on mcb for lights circuit(43V).....doesn't make sense???
     
  4. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
    15
    2
    Tnx for reply,
    Should the voltage at entry point (main breaker on db) not be a constant at 220-240V with all or no breakers in the on position?
     
  5. dannyf

    Well-Known Member

    Sep 13, 2015
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    I think you may be living in an alternate universe.

    Essentially yoybare saying that there is voltage but there is no voltage.

    Logic would dictate that both statement cannot be true att the same time.
     
    bwilliams60 likes this.
  6. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    Could you detail how you setup and connected your voltmeter's probes to the wires? Because I'm assuming that you've actually measured things up
     
  7. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
    15
    2
    Hi, tnx for reply.
    I might be living in a alternate universe but help me out if you can...
    I've got a fluke T150 voltage tester, if I touch any one of the probes on either live or neutral terminals of main switch,the AC light lights up.
    If I connect red to live and black to neutral terminals, with all breakers in db board to off position I still only have AC light lit up.
    If I switch earth leakage (and main) switch on, I get 102V.
    If I switch lights circuit on, I read 42V (lights circuit does not work-no lights come on)
     
  8. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
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    This is all measured at the supply side of the main breaker with black to neutral and red to live
     
  9. DGElder

    Member

    Apr 3, 2016
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    Hard to tell what you are doing, but it sounds like a short or a problem with the house supply. But if it was a short the breakers should trip. The supply side voltage should not change significantly with normal loading. Why are you measuring? Is there a problem? Describe the problem in detail, all symptoms and your diagnostics.
     
    Last edited: Jun 22, 2016
  10. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
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    The earth leakage tripped and when I switched it back on it tripped again, second time it stayed on but none of the house circuits worked( no lights or plugs came on).
    That's why I started measuring, to see if I'm actually getting something from the supply.
    I just switched on some circuits and the earth leakage tripped, without resetting the earth leakage I measured again and read 230V on the supply(that's more or less what I would expect) but resetting the earth leakage I'm back to where I started with 0V, and 102V when earth leakage is on etc.(as explained earlier)
    Maybe the earth leakage switch broke or malfunctioning?
     
  11. wayneh

    Expert

    Sep 9, 2010
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    Try measuring with a small load such as a 7W lightbulb attached in parallel to your probes. I think you're just seeing ghosts.
     
    cmartinez likes this.
  12. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
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    Its to dark to see ghosts, all I see is my phone screen at the moment....
    And luckily my T150 has a convenient integrated led to light up the db board when taking measurements.
     
  13. dannyf

    Well-Known Member

    Sep 13, 2015
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    I would say that with the knowledge you have demonstrated so far, it is far better for your safety and those around you that you don't poke around live mains circuits. You risk series injuries to yourself and others. If you really love this thing, get trained first and then come back.

    Better safe than sorry.
     
    Rodney Phillips likes this.
  14. wayneh

    Expert

    Sep 9, 2010
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    I don't think an LED is enough of a load, and anyway it's powered by the battery in your meter, not the circuit under test.

    Your meter (like others) places almost no load on a circuit, by design, and can pick up stray inductances that appear as voltages. These will disappear when a small load is applied.

    If they don't, then you have something very strange going on. As suggested, you should consider involving a professional.
     
  15. DGElder

    Member

    Apr 3, 2016
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    I just switched on some circuits and the earth leakage tripped.

    Turn on one branch circuit at a time and see which one is leaking to earth, i.e. which one trips the earth breaker. It would seem you have a short somewhere in that circuit or some leakage anyway.

    In what country is this house?
     
    Last edited: Jun 22, 2016
  16. tcmtech

    Well-Known Member

    Nov 4, 2013
    2,034
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    Are you sure you're not missing a decimal point and its millivolts you are reading and not volts? o_O

    What's the meter say when you connect it to an extension cord that is not plugged into anything?
     
  17. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    That's exactly what was on my mind
     
  18. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
    15
    2
    Tnx everyone!
    For your input and thoughts I'm gratefull but there is something seriously wrong here, must be on the supply to the house.
    I left mains, earth leakage and one lights circuit in on position and when I woke up the lights on that circuit came on during the time I left it.
    Tested exactly the same as earlier and got my 230V on mains supply and then switched on 1 breaker at a time, testing the mains between each breaker with a resulting 230V every time....
    For now it sorted it self out. Weird, that's why I joined the forum cause its not the first time it happens and even the electricians I had here could not figure it out(because when they get here every thing measures correctly as it is at the moment) they just test and tell me there is nothing wrong.
    I do not know what yo do...
     
  19. jaco_boon

    Thread Starter New Member

    Jun 22, 2016
    15
    2
    SA
     
  20. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    I suggest you re-measure things with a small load applied, as wayneh just mentioned.
     
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