Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • Locked Locked
  • Replies 23 replies
  • Subscribers 36 subscribers
  • Views 9113 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

4mm Radial off a 32A Ring

WireWeHere

The ring is 2.5mm fed by 32A MCB. I know that I can run a single fitting (e.g. 2-gang socket) off a ring as a spur. Alternatively, I believe I can run a fused radial off the ring as the fuse stops excessive current doing down the radial. However, can I run a 4.0mm radial (unfused) off the ring as a 4.0mm radial is rated to carry 32A (single phase)? It feels logical as you can have a 32A 4.0mm radial on its own and the ring supports 32A. I appreciate logic doesn't always apply though.

Parents
  • WireWeHere said:
    It feels logical as you can have a 32A 4.0mm radial on its own and the ring supports 32A.

    Can you? If T&E or multicore not armoured), only clipped direct (ref method C) ... or where overload protection is not required ... i.e. not for socket-outlets. Have a look at Table 4D5 for example. Insulated and sheathed singles would be OK clipped direct, also insulated singles in a surface-mounted conduit or trunking with no derating factors at all.

    So in reality, looks like it's doubtful for many applications for socket-outlets generally.

Reply
  • WireWeHere said:
    It feels logical as you can have a 32A 4.0mm radial on its own and the ring supports 32A.

    Can you? If T&E or multicore not armoured), only clipped direct (ref method C) ... or where overload protection is not required ... i.e. not for socket-outlets. Have a look at Table 4D5 for example. Insulated and sheathed singles would be OK clipped direct, also insulated singles in a surface-mounted conduit or trunking with no derating factors at all.

    So in reality, looks like it's doubtful for many applications for socket-outlets generally.

Children
  • in reply to gkenyon

    Buried in masonry?

    Derating factors apply to all cables so using it as an excuse to say WWH cannot do what he suggests is just fatuous.

  • in reply to geoffsd
    geoffsd said:
    Derating factors apply to all cables so using it as an excuse to say WWH cannot do what he suggests is just fatuous.

    I never said can't, just that the application is potentially rather limited.

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines