1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Replace MCB with RCBO's

Discussion in 'Electrics UK' started by Licklieder, 4 May 2021.

  1. Licklieder


    2 Oct 2010
    Thanks Received:
    United Kingdom
    Having read the IET post and the spec sheet, the quoted losses of 1.5W to 2.5W maximum are for full load - so at 32A for a 32A RCBO, which would equate to about 0.013%. Someone in the discussion posits the losses being I2R losses, which would mean at low loads they would become negligeable - the 32A example, would scale to a max loss of 2.4 mW at 1A. Someone else towards the end of the discussion quotes a measurement of 10mA across 5 RCBO with no load, so 2mA per RCBO or 0.46W. - which would equate to ~ 4kWh a year per RCBO.

    Now, in my situation I have electric heating / hot water which, with all the tech i run equates to an annual usage of about 9,000 kWh. Taking the 10mA figure for losses, The annual consumption of 32 kWh for having all RCBO fitted in my CU will get lost in the noise. I can likely save that by turing the heating on a or two day later. To me, its small beans and worth it for the additional circuit discriminiation in the case of a fault.
  2. DIYnot Local

    DIYnot Local

    3 Sep 2019
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.

    Are you a trade or supplier? You can create your listing free at DIYnot Local

  3. Sponsored Links

Share This Page