How many KVA for a new domestic supply ?

Discussion in 'Electricians' Talk' started by Gerry Built, Oct 6, 2006.

  1. Gerry Built

    Gerry Built New Member

    I am getting a new domestic supply put in as the current supply needs to be moved due to me selling part of my garden off. To get a quote from Electricity Board they want me to specify the total load for the new supply in KVA. I tried the 'same as I have now' approach but they wont accept that. Can anyone tell me what a typical domestic supply for a 5 bedroom house should be (in KVA) ?


  2. eawr89

    eawr89 New Member

    24kVA (standard 100A cut-out)
  3. sinewave

    sinewave Screwfix Select

    100amps x 230 volts / 1000 = 23 kva (single phase)
    Therefore a quick ref is 0.23 per line amp

    100amps x 400 volts x 1.732 / 1000 = 69.28 kva (3 phase)
    (0.69 per line amp)

    However DNO’s round down to the following easy to remember standards and usually class supplies as follows.

    A standard domestic service at 15 KVA usually has a 60-amp cutout fuse.
    A standard domestic service at 20 KVA usually has an 80-100-amp cutout fuse.
  4. Gerry Built

    Gerry Built New Member

    Thanks lads

  5. sparkin!

    sparkin! New Member

    100amps x 400 volts x 1.732 / 1000 = 69.28 kva (3 phase)
    (0.69 per line amp)

    assuming unity pf!;-)

    LECH WALESA New Member

    you ****** already
  7. Lectrician

    Lectrician Screwfix Select

    WPD will treat anything above 12kW with 'caution', and will look to provide 3 phase for anything above 18kW.

    If you were to ask your DNO for their typical max demand for domestics, they will tell you. Then simply quote that.

    Off peak has very different rules!

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