Reason for this check

Discussion in 'General Electronics Chat' started by redsierra, Apr 9, 2013.

  1. redsierra

    Thread Starter New Member

    Oct 20, 2011
    I have a carpet cleaner, electrical operated and as soon it is switched on my
    house consumer unit trips.

    I was told to check the live and earth & neutral and earth by using an analogue
    meter set to x10k ohms. That is the meter positive probe to live wire and the
    negative probe to earth wire. Then the positive probe to the neutral wire and the
    negative probe to the earth wire. I was also told not to get a low reading
    during this check.

    Why and for what reason I have to do this?
    What low reading is unacceptable, in other words how much a high reading to be

    I thank you in advance for any help to this problem
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    If you have an RCD consumer unit, it monitors the earth leakage current, so if your cleaner has a bad connection between the Live and earth, or neutral and earth it will cause the RCD to trip.

    A good insulation reading of 100meg or higher is better.

    using a low resistance meter i would look for a reading over 10K ohms
  3. crutschow


    Mar 14, 2008
    For a good insulation reading you should get an over-range, even on the highest resistance setting. Any resistance reading, even in the megohm range is suspect. It could indicate a problem at the higher line voltage.
  4. kubeek


    Sep 20, 2005
    I seriously hope those are the wires of the carpet cleaner. If you did this in the socket, the meter would blow up.