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Definition of 'electrical installation' and requirement to upgrade existing to current regs?

MFr

Hi there

Have found an old damaged 30A JB on a ring final under the floorboards, which I was going to replace - although it spurs to a 2G socket, from which three further sockets are spurred. Obvs you can't have a spur off a spur without a fused connection (which this doesn't have), but is there a specific requirement to upgrade the existing wiring either (a) once the 'non compliant' aspect has been found or (b) as a result of the intervention in the circuit (i.e. does the replacement of the broken JB automatically mean that the spur+spur issue has to be rectified also?).

The wiring is not that old (blue neutral plus other evidence suggests probs 15 - 20-ish years max) so not sure if it would have even been compliant with the regs at the time - but would be pretty difficult to either bring the spurs back to the ring or fit a fused connection due to the location / buried cables etc etc. Might be possible to split the ring into two radials etc (which would probably have incidental benefits) but obvs this is an order of magnitude more substantive work-wise than replacing the damaged JB... 

Cheers

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  • 0

    It is in my view acceptable to down rate the ocpd for a ring final to 20 amps, provided that the maximum sustained demand is reasonably expected to be 20 amps or less.

  • 0 in reply to broadgage

    acceptable to down rate the ocpd for a ring final to 20 amps,


    Agree, and quite common when the ring has lost its ring and become 'crab claws' or Christmas Tree spurs or similar. This reduces a risk of burning the house down to a risk of getting a bit hacked off because it trips occasionally, and if that encourages a more careful use pattern, that avoids the overload and tripping,  that outcome is very good. If it encourages a call back for a rewire, also good ;-)

    If we really believed a fuse or breaker could never ever be used as a load limiter, then all socket circuits  would be limited to supplying a maximum of 2 and a bit 13A sockets, and or  we should dispense with the 32A breakers as they are superfluous.

    I suspect neither interpretation is what the author intended however.

    Mike.

  • 0 in reply to mapj1
    mapj1 said:
    If we really believed a fuse or breaker could never ever be used as a load limiter, then all socket circuits  would be limited to supplying a maximum of 2 and a bit 13A sockets, and or  we should dispense with the 32A breakers as they are superfluous.

    Yes.

    Wasn't there a time when all sockets were on 16 A radials? In those days, there were no spurs.

  • 0 in reply to Chris Pearson

    Wasn't there a time when all sockets were on 16 A radials?
    Nominally 15A or 5A radials, one per socket, BS3036 style hot wire fuses.

    Even by the 1929 9th edition, that had gone..

     could  have more sockets, Not much later, then earths were also required on new socket circuits, since just after the war - its been a verylong while since one wire one socket, and all that sort of stuff was being taken out from the 1970s onwards.

    Mike.

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  • 0 in reply to Chris Pearson

    Wasn't there a time when all sockets were on 16 A radials?
    Nominally 15A or 5A radials, one per socket, BS3036 style hot wire fuses.

    Even by the 1929 9th edition, that had gone..

     could  have more sockets, Not much later, then earths were also required on new socket circuits, since just after the war - its been a verylong while since one wire one socket, and all that sort of stuff was being taken out from the 1970s onwards.

    Mike.

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