Multiple phase wires in circuit breakers

[Sparkysystem]

Happy to go along with radials in length though this does not seem to change the principle of the statement.

Agree completely that 'shouldn't really mix ring and radial' but have not yet found where BS7671 states that it's wrong.

Circuit breakers are designed to take at least 2 cables and the form of erection must be safe and functional.

I need to emphasize I'm not looking to install like this. Equally I don't want to tell customers they must have their wiring reworked if they don't need to. I want to know when to tell them their wiring definitely contravenes BS 7671 and when it just not following best practice.

 

[Sparkysystem]

Just been reading Trevor Marks and he points us to BS 7671 314-01-04 that is copied below.

"Where an installation comprises more than one final circuit, each final circuit shall be connected to a separate way in a distribution board. The wiring of each final circuit shall be electrically separate from that of every other final circuit, so as to prevent the indirect energising of a final circuit intended to be isolated".

This seems to kill the radial and ring final circuit being fed from a single circuit breaker stone dead.

Does this change the suggestion that a single circuit breaker can feed 2 radial wires for a lighting circuit?

Does this change the suggestion that a single circuit breaker can feed 2 radial wires for a circuit supplying socket-outlets?

 

[Adam_151]

This seems to kill the radial and ring final circuit being fed from a single circuit breaker stone dead.

Yes, It's clearly two separate circuits in this case, and you can't feed them from the same breaker

Does this change the suggestion that a single circuit breaker can feed 2 radial wires for a lighting circuit?

Its a single radial thats branched that the CU, no different to branching at a light fitting, of course, having branched radials can make testing a little more involved

Does this change the suggestion that a single circuit breaker can feed 2 radial wires for a circuit supplying socket-outlets?

Same answer as the light one, its just branched, of course if you have a branched 16A radial, its 50m² max floor area total, not 50m² per branch, and of course the point above about testing not being so straightforward is also relevant