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-   -   Earth and voltage generator problems (https://www.askmehelpdesk.com/showthread.php?t=717297)

  • Nov 16, 2012, 09:57 AM
    KDP74
    Earth and voltage generator problems
    Just bought a second hand diesel generator and connected it up to consumer unit powering sockets and lights in some stables. Maximum voltage output is showing160 volts and showing no earth even though the generator is earthed to an earth electrode. What's the problem?!
  • Nov 16, 2012, 11:03 AM
    hfcarson
    Can you give us a little more info...
    What size is the genset? (kW?)
    What kind of electrode is connected? Ground rod?
    Are the neutral and ground points on the generator connected
    Together or are they separated.
    How much load in kilowatts is connected and operating?
  • Nov 16, 2012, 11:17 AM
    KDP74
    Quote:

    Originally Posted by hfcarson View Post
    Can you give us a little more info...
    What size is the genset? (kW?)
    What kind of electrode is connected? Ground rod?
    Are the neutral and ground points on the generator connected
    together or are they separated.
    How much load in kilowatts is connected and operating?

    Generator is 3 kw and loading is about 2.4kw. Earth rod is connected to earth terminal on front of generator. As for the neutral and ground points being connected on generator I'm afraid I don't know. Could this be my problem?
  • Nov 16, 2012, 11:32 AM
    hfcarson
    Does this structure have a utility electric service?
  • Nov 16, 2012, 11:58 AM
    KDP74
    Quote:

    Originally Posted by hfcarson View Post
    Does this structure have a utility electric service?

    No incoming utility electric supply
  • Nov 16, 2012, 12:18 PM
    hfcarson
    So this is what's known as a separately derived system...
    What you need to accomplish is a solid connection between the
    Ground, the neutral and the grounding electrode...
    This is the same way as your utility service at the first disconnect is also
    Bonded to ground.
    Now the Voltage level concerns me, how do you know it is 160 volts?
    If this was the meter on the genset, can you confirm this with a digital multimeter?
  • Nov 16, 2012, 12:32 PM
    KDP74
    Quote:

    Originally Posted by hfcarson View Post
    So this is what's known as a separately derived system...
    What you need to accomplish is a solid connection between the
    ground, the neutral and the grounding electrode...
    This is the same way as your utility service at the first disconnect is also
    bonded to ground.
    Now the Voltage level concerns me, how do you know it is 160 volts?
    If this was the meter on the genset, can you confirm this with a digital multimeter?

    Is that like a TNC-S supply? I borrowed an earth loop impedance meter and got a reading with that. Not entirly sure how accurate it is as I was told the meter had not been calibrated for 16 months although it was never used since its last calibration date. Meter said incorrect wiring. And when I plugged in a socket tester to a socket it said there was no earth present.
    Somebody told me to put a link in the fuse board between the neutral and earth bars. Haven't tried that yet though!
  • Nov 16, 2012, 12:37 PM
    hfcarson
    I don't know the specific wiring configuration of your genset but, yes the neutral and ground do need to be connected together...
    If you are not sure about what to do, try to Google the manufacturers installation instructions before you make any adjustments or connections you are not completely sure of...
    ***Again, how do know you have 160 Volts? Meter on the genset? Digital multimeter?
  • Nov 16, 2012, 12:42 PM
    KDP74
    Quote:

    Originally Posted by hfcarson View Post
    I don't know the specific wiring configuration of your genset but, yes the neutral and ground do need to be connected together...
    If you are not sure about what to do, try to google the manufacturers installation instructions before you make any adjustments or connections you are not completely sure of...
    ***Again, how do know you have 160 Volts? Meter on the genset? Digital multimeter?

    I used a plug in loop impedance meter which shows your voltage before you commence with any of the tests and it showed 160 volts, but as it said incorrect wiring I thought better of going any further.
  • Nov 16, 2012, 12:45 PM
    KDP74
    Quote:

    Originally Posted by KDP74 View Post
    I used a plug in loop impedance meter which shows your voltage before you commence with any of the tests and it showed 160 volts, but as it said incorrect wiring I thought better of going any further.

    I plugged the meter in to a socket outlet if that's any help
  • Nov 16, 2012, 12:56 PM
    hfcarson
    I would still prefer a multimeter to verify voltages to neutral and ground...
    If you are actually getting a 160Vac output then this generator may be
    Malfunctioning.
    Using a voltage meter, test from Hot to Neutral, then Hot to Ground, then Neutral to Ground.
    You should read... ~120 Vac, ~120 Vac, and 0 Vac, respectively. If you can do this, let me know what you get.
  • Nov 16, 2012, 12:59 PM
    hfcarson
    You plugged it in to a socket?
    And it said what?
  • Nov 16, 2012, 01:21 PM
    KDP74
    Quote:

    Originally Posted by hfcarson View Post
    you plugged it in to a socket?
    and it said what?

    It said P-E correct and P-N correct. But a red light was lit saying incorrect wiring, do not proceed. I'll try what you suggest with the voltmeter and see what I get.
  • Nov 16, 2012, 01:43 PM
    KDP74
    [QUOTE=KDP74;3326423]It said P-E correct and P-N correct. But a red light was lit saying incorrect wiring, do not proceed. I'll try what you suggest with the voltmeter and see what I get.[/QUOTE

    Thanks a lot for your help and I'll get back to you
  • Nov 16, 2012, 01:44 PM
    hfcarson
    Good luck!
  • Nov 16, 2012, 05:11 PM
    Kyle_in_rure
    Judging by the terminology used, I think the poster is outside of the U.S. in a country that probably uses 240/230V Mains.

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