On the contrary, and with due respect to both of you, I would say that it is Simon and yourself who are doing that. What I have been doing is presenting what I believe to be a very simple and sensible (I hesitate to say 'fairly obvious'!) interpretation of what is intended by Table 51 of BS7671.
... and I said exactly the same, very early on in this discussion- namely that my view is that everything determining whether or not current flows through the coil of a relay/contactor is a "control circuit", and anything carrying the full load current (switched by the contacts of the relay/contactor) is the "power circuit".
Well, you know my views about that - as expressed recently and above. If one uses something like my 'definition' in red above, there is no 'blurring'.
To again repeat myself, I really don't think that many people (or BS7671) would describe a lighting circuit (including the lamp!) or an immersion circuit (including the immersion) as a "control circuit" - and nor could I see any point in such a description.
Blurring only arises in the absence of adequate definitions. If one adopts (I would say 'sensible') definitions like my red above, it would be rare (if ever) for the situation not to be a 'black and white' one.
As you will realise from what I believe and have just written. I would say that everything 'controlling' the current in the coil of a relay/contactor was a "control circuit" (quite possibly using a different voltage from the "power circuit", and that everything in the circuit switched by the contacts of the relay/contactor ('controlling' current flow to the end-load" is a "power" circuit.
Maybe this is really what we are really talking about - logistical/'bureacratic' demarcations (which, as you imply, may be well-intentioned), rather than any sensible electrically-based distinctions?
As you will realise from what I've recently written, I totally agree (see my 'red definitions' above').
OK then, as drawn above, 1-4 are all power conductors by your definition - agreed ?
I assume that you're talking about your drawing (since mine had 1-3 and 1-8) - in which case, yes, I agree.
Yep, that's what 'my' convention would say (in that simple situation). It perhaps becomes clearer if one thinks of a situation in which all your 1-4 (timeswitch and 3 stats), hence also the signal line to the boiler, were operating at ELV. In that situation I doubt that anyone would deny that all of that was a 'control ciciruit', separate from the LV "power circuit" connected to the boiler (which would take the full load current when the boiler was 'on').
As I wrote ....But you are equally adamant that 1-3 are power because they carry the pump current. Yup, totally black and white
... so, yes, you have managed to come up with an area which is 'grey', rather than black and white, since, with the pump per your drawings, it is a 'dual-purpose circuit. That is, of course, only possible because the control circuitry is LV, so one can ('conveniently') use what is a control circuit for the boiler as a power circuit for a pump. If, as above, the control circuitry was ELV, one would have to incorporate relays/contactors to operate the pump (which is the situation I have in my house) - in which case the situation (per my definitions) becomes 'black and white' again.
It has, but not only is it quite interesting, but it also does remain largely on topic because of the implications of what is being discussed in relation to the permissible colour identification of a switched L.
It does, and I almost mentioned that earlier. However, I suspect/presume that what it means is that "for the purpose of this table, Power circuits include lighting circuits". ... so the nonsense of Table 52.3 probably still applies as far as Table 52.3 is concerned!
Yes, but I thought you had agreed with me a while back that, in the context of our discussion, "circuit" is not the right word, so neither the 'traditional' or BS7671 definition of "a circuit" really applies.
All it had to say, then, was "power and lighting circuits" - but it didn't so can't have it both ways.
It's obviously open to debate, and BS7671 is seemingly silent on the matter. Your view may well be 'operationally reasonable' in truly complex situations, even if not based on any 'electrical logic' - but I would question the 'complexity' of a simple circuit which, say, supplied a control signal to a boiler and power to a pump. In any event, in terms of this thread, I remain of the view that it is not really either appropriate or useful to describe a lighting circuit with a manual switch as a 'control circuit'!
Again, quite probably 'operationally reasonable' if the situation is complex, but not really based on anything electrical.
It can have it both ways because it's not legal text, e.g. legislation. The clear intent of these two tables is beyond any reasonable question whatsoever. Certainly comment upon the poor wording to JPEL/64 when the next draft is out (assuming it hasn't been corrected for that) - but it's extremely silly to pretend that it means anything other than what it very obviously means.
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