Choosing best rating circuit breaker to protect 16A commando socket

I was installing a 16A commando socket today which I protected with a 30mA rcd followed by a 16A MCB.

Other breakers nearby were not heavily loaded so derating was not an issue. But if I say wanted to connect to a heavily loaded consumer unit my initial reaction would be to put in something like a 20A breaker and suitable cable.
But then I thought the socket and plugs are not fused and I have no control over the cable connected to the socket. Therefore do I have to assume I am protecting a cable that is only rated at 16A and never use a breaker with a rating that exceeds this?

Parents
  • But if I say wanted to connect to a heavily loaded consumer unit my initial reaction would be to put in something like a 20A breaker

    Alternatively you could use a 16A MCB and a spacer each side to mitigate the warming from adjacent devices. In many cases, where the uprating of the protective device would have knock-on consequences, that may well be the preferred approach.

      - Andy.

Reply
  • But if I say wanted to connect to a heavily loaded consumer unit my initial reaction would be to put in something like a 20A breaker

    Alternatively you could use a 16A MCB and a spacer each side to mitigate the warming from adjacent devices. In many cases, where the uprating of the protective device would have knock-on consequences, that may well be the preferred approach.

      - Andy.

Children
  • Another option (granted not a first choice in many cases) might be a larger OCPD in the DB sized to take account of the group derating, with a closer (in this case 16A) device providing overload protection downstream. If the cable twixt the two were sized appropriately, you might then have created room for future expansion rather than using up multiple ways.