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Type A rcd . EICR coding ? etc

aligarjon
Hi Guys.   Not been on for a long time, just had a bit of a search and couldn't really find anything so thought i would ask and see what you all thought.


1.  Are we or will we be coding type AC rcd's if there are LED's or induction hobs, lots of electronics  etc  present.

2. How much DC leakage does it actually take to saturate an rcd and cause  problem?

3. How much does a standard LED lamp or induction hob  leak ?

If we test an AC RCD with no load and it's fine then re-test it with all LED lights, induction hobs etc turned on and it operates correctly could we then say that it is ok with a note on EICR  OR EIC if installing any of the above.  


Obviously also on an EICR if the RCD then doesn't operate with it all on it becomes a C2 ?


Any thoughts



Gary
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  • 0
    davezawadi (David Stone):

    Hi Graham


    Figure A53.1 shows waveforms which may cause some RCDs difficulties. We discussed those at length above. However, that was not the question I asked which was (written more clearly perhaps) "How can any credible fault produce those waveforms, and if it can, will it operate various types of RCD?" which is very different. I can always say "We need to provide additional protection of the highest level for safety" but that is not the correct answer at all, although it smacks of the usual British Gold plating of any possible regulation or even idea. I am interested in Credible faults that could occur, and once one is established, how often could it happen, in other words, the normal risk assessment criterion. It is unacceptable to expect to make everything completely zero risk, although some like to try and do so, particularly when it costs them nothing or worse when it makes them a profit!



    Kind regards

    David


    No, David, Figure A53.1 shows faults that can and do occur downstream of the particular rectification or control arrangement shown - have a look at the diagram in Column 1, which shows the point of fault (effectively downstream of that point), and the fault waveform. The problem with half-wave rectified mains is it contains complex components, as I'm sure you're aware.


    So, where could these faults occur? Some examples include:



    • Cable supplying equipment downstream from the particular source being discussed

    • Wiring in the equipment itself


    And as to "how often can it happen" ... well, we might as well all go home, because electrical faults in the grand scheme of things are far less frequent than road accidents, far less fatal, and cost far less, than RTAs
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  • 0
    davezawadi (David Stone):

    Hi Graham


    Figure A53.1 shows waveforms which may cause some RCDs difficulties. We discussed those at length above. However, that was not the question I asked which was (written more clearly perhaps) "How can any credible fault produce those waveforms, and if it can, will it operate various types of RCD?" which is very different. I can always say "We need to provide additional protection of the highest level for safety" but that is not the correct answer at all, although it smacks of the usual British Gold plating of any possible regulation or even idea. I am interested in Credible faults that could occur, and once one is established, how often could it happen, in other words, the normal risk assessment criterion. It is unacceptable to expect to make everything completely zero risk, although some like to try and do so, particularly when it costs them nothing or worse when it makes them a profit!



    Kind regards

    David


    No, David, Figure A53.1 shows faults that can and do occur downstream of the particular rectification or control arrangement shown - have a look at the diagram in Column 1, which shows the point of fault (effectively downstream of that point), and the fault waveform. The problem with half-wave rectified mains is it contains complex components, as I'm sure you're aware.


    So, where could these faults occur? Some examples include:



    • Cable supplying equipment downstream from the particular source being discussed

    • Wiring in the equipment itself


    And as to "how often can it happen" ... well, we might as well all go home, because electrical faults in the grand scheme of things are far less frequent than road accidents, far less fatal, and cost far less, than RTAs
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