Lights From Plug Socket

[JohnW2]

Do we all know "roughly" how a power circuit differs from a lighting circuit?

As I have said, twice or more, if we didn't, then we are all very wrong to use the term so widely. As you know as well as I do, at least in the sense that you and I intend when we use the term, a "lighting circuit" is ("roughly") one in which the loads are predominantly lighting, whilst a 'power" circuit is one in which that is not the case ... and please don't start throwing 'exceptions' at me, since I'm more than capable of thinking them up for myself.

Do any of us understand, even vaguely, what is insufficient with Ib ≤ In ≤ Iz?

Why are you asking again? - I have already said, and repeated, that I think it defies logic to 'over-ride' that with a requirement based on the 'type' of circuit? ....

Whatever the definitions or 'intended meanings', the fact that there are different minimum CSAs for cables in "lighting" and "power" circuits, per se, rather than determined by the design current of the circuit (perhaps with a blanket minimum of, say, 1mm²), seems to defy logic.

Kind Regards, John

 

[EFLImpudence]

I've explained before:

It is only non-sheathed and sheathed cables wich are subject to the 1mm² minimum csa for lighting circuits.
Table 52.3 clearly states that you may use 0.75mm² non-sheathed and sheathed flexible cables for any other application than for a specific appliance where the product standard says otherwise which, indeed, may be smaller.

So, the actual minimum depends on whether you think non-sheathed and sheathed flexible cables are themselves non-sheathed and sheathed cables.
You may think they are not, and that non-sheathed and sheathed cables means twin and earth so the 1mm² minimum would then definitely apply because it is not made any smaller than that.

The real problem lies in the non-sheathed and sheathed cable 1.5mm² minimum for power circuits where you may want to supply power to an individual appliance (which may be a light) but of course, you may use the non-sheathed and sheathed flexible cable minimum of 0.75mm² under the any other application clause - or, as it will be for a specificic appliance, smaller.

It all depends on whether you can bend non-sheathed and sheathed cables. I am sure you can.

I hope this helps.

 

[JohnW2]

I hope this helps.

Thank you

I really don't know why we spend so much time repeatedly talking about this wretched Table, since I think we are all agreed that it is nonsense, and all of the anomalies have been pointed out many times.

As you imply, in practice the only time there is usually an issue is when one would like to use (and could use, electrically speaking) 1mm² T+E for what would probably have to be called a 'power' circuit. The rest of the silliness does not usually have much impact.

Kind Regards, John