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BS7671;2018 Minor works certificates.

Sparkingchip
Are you all organised and have a supply of the new certificates to hand?


What do you actually think of them?


Andy B.
Parents
  • 0

    Chris Pearson:




    Graham Kenyon:

    John,


    In general, I don't really disagree with you, but ...




    If an RCD does not trip at 1 x Idelta n then it is defective. This softer test is a better indicator of RCD health than the 5 x test and consumer safety.






    This does not unfortunately take account of a small number of cases where the RCD passes a 1x test, but then goes on to fail a 5x test, although I agree this is not simply a case of "sticky RCD".




    For my own peace of mind, at home, I would wish to be assured that an RCD does trip as intended. If passing at 5x means that one will also pass at 1x, then all well and good: only the one test is required. However, if not, then surely both tests are required.


    Of course, there is no reason to stop doing the 5 tests, it is just that only one time needs to be recorded in the EIC/EICR (plus the all important test button).


     




    I'm still not satisfied. There are also the cases where the 1x time passes (i.e. < 300 ms) but does not provide evidence of compliance for 643.7.1(b) - in particular the disconnection time recorded > 200 ms in cases when Chapter 41 demands 0.2 s disconnection time.

    And the even greater number of cases where 643.8 is not verified by the 1x test - in particular disconnection time recorded > 40 ms (per the Note to the regulations)?


    Surely, this is the purpose of the verification stated in the Regulations, and if the evidence is not there, from the test as specified, then the particular requirements of Chapter 41 for ADS are not met - similar to a high loop impedance reading where OCPDs are relied upon to provide ADS?


    Presented with a set of test results that record the fact that the requirements have not been met, and certified by a competent person by their signature, what else could a court decide?


    Sure, if the 1x test is below 40 ms (as might be the case) then no-one would know the difference. But this doesn't help anyone decide what is really necessary.

    For a 30 mA RCD, there is rarely a reason to not carry out the 5x test, and record the result. I agree with larger residual current ratings, the 5x test is not desirable, but the way the 18th Edition requirements are written does not really afford us a means of providing evidence compliance (unless of course you're lucky enough to be able to achieve the required disconnection time on the 1x test).


    This is why I don't subscribe to the "only record 1x" ...

     

Reply
  • 0

    Chris Pearson:




    Graham Kenyon:

    John,


    In general, I don't really disagree with you, but ...




    If an RCD does not trip at 1 x Idelta n then it is defective. This softer test is a better indicator of RCD health than the 5 x test and consumer safety.






    This does not unfortunately take account of a small number of cases where the RCD passes a 1x test, but then goes on to fail a 5x test, although I agree this is not simply a case of "sticky RCD".




    For my own peace of mind, at home, I would wish to be assured that an RCD does trip as intended. If passing at 5x means that one will also pass at 1x, then all well and good: only the one test is required. However, if not, then surely both tests are required.


    Of course, there is no reason to stop doing the 5 tests, it is just that only one time needs to be recorded in the EIC/EICR (plus the all important test button).


     




    I'm still not satisfied. There are also the cases where the 1x time passes (i.e. < 300 ms) but does not provide evidence of compliance for 643.7.1(b) - in particular the disconnection time recorded > 200 ms in cases when Chapter 41 demands 0.2 s disconnection time.

    And the even greater number of cases where 643.8 is not verified by the 1x test - in particular disconnection time recorded > 40 ms (per the Note to the regulations)?


    Surely, this is the purpose of the verification stated in the Regulations, and if the evidence is not there, from the test as specified, then the particular requirements of Chapter 41 for ADS are not met - similar to a high loop impedance reading where OCPDs are relied upon to provide ADS?


    Presented with a set of test results that record the fact that the requirements have not been met, and certified by a competent person by their signature, what else could a court decide?


    Sure, if the 1x test is below 40 ms (as might be the case) then no-one would know the difference. But this doesn't help anyone decide what is really necessary.

    For a 30 mA RCD, there is rarely a reason to not carry out the 5x test, and record the result. I agree with larger residual current ratings, the 5x test is not desirable, but the way the 18th Edition requirements are written does not really afford us a means of providing evidence compliance (unless of course you're lucky enough to be able to achieve the required disconnection time on the 1x test).


    This is why I don't subscribe to the "only record 1x" ...

     

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