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High protective conductor currents - Deletion of 543.7.1.204

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
  • Thanks Graham. So torque screwdrivers now required to change a light switch seems the way we are going. At least that fitting has the Blackwell Inheritance.

    There are no torque requirements for the mk rapidfix range, they have those sprung connectors, and they have no spare Blackwell Inheritance either.

Reply
  • Thanks Graham. So torque screwdrivers now required to change a light switch seems the way we are going. At least that fitting has the Blackwell Inheritance.

    There are no torque requirements for the mk rapidfix range, they have those sprung connectors, and they have no spare Blackwell Inheritance either.

Children
  • There are no torque requirements for the mk rapidfix range, they have those sprung connectors, and they have no spare Blackwell Inheritance either.

    It's up to the designer / installer what products to use for which purpose.

    In any case, we are talking about individual BS 1363-2 socket-outlet plates here, not complying with BS 7288, which, on the vast majority of circuits complying with 411.3.3, would be required to have a maximum protective conductor current of 9 mA, and therefore Blackwell Inheritance not necessary even to BS 7671:2018+A1:2020?