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High protective conductor currents - Deletion of 543.7.1.204

AJJewsbury

543.7.1.204 - the one about duplicate c.p.c.s needing to be 'terminated independently of each other' - has gone.

Does anyone understand the thinking behind this? It seems a bit odd to me.

Given that (in my experience) more problems occur at terminals rather than along cable runs, if we need the c.p.c.s to be duplicated, it seems like a bit of a flaw that one single loose connection can make them both useless simultaneously. I can see that in some instances (e.g. a terminal on a socket on a ring) that losing a single terminal carries a limited immediate risk (as the leakage current from a single socket should be small and all other sockets are still connected to a c.p.c.) but in other instances - say the connection of both c.p.c.s to the earth bar in a DB - that single fault could be very significant.

   - Andy.

Parents
  • gkenyon said:
    unless it's somewhere like a data centre

    Or non-domestic where a risk assessment has been done. But i agree, RCDs put a practical limit on the level of protective conductor currents that can occur. 

    Another example perhaps of our reliance on RCDs to hopefully do their job, in the absence of "belt and braces" methods.

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  • gkenyon said:
    unless it's somewhere like a data centre

    Or non-domestic where a risk assessment has been done. But i agree, RCDs put a practical limit on the level of protective conductor currents that can occur. 

    Another example perhaps of our reliance on RCDs to hopefully do their job, in the absence of "belt and braces" methods.

Children
  • in reply to OlympusMons
    OlympusMons said:
    Or non-domestic where a risk assessment has been done.

    But the risk assessment route has been tightened up a little more in Reg 411.3.3 in Amendment 2:2022

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