A ring final supplying what?Only, as you know, if it's a ring final.Does a circuit supplying indeterminate loads which are not prevented from reaching 32A, on a 32A OPD, but wired using a cable with a CCC of < 32A comply with 433.1.1?
A ring final supplying what?Only, as you know, if it's a ring final.Does a circuit supplying indeterminate loads which are not prevented from reaching 32A, on a 32A OPD, but wired using a cable with a CCC of < 32A comply with 433.1.1?
FGS, Eric - that's why I put 'legality' in quotes.The is nothing legality to stop anyone feeding a CU from a ring final. BS7671 is not a legal document although following it's recommendations is one way to show due care and attention was used and the electrician had a warranty of skill.To the "legality" of supplying a CU from a ring final.
Please tell us which regulation permits that. If you cannot, then you clearly cannot be correct.As I have already said fitting shaver sockets through an isolating transformer is permitted from a ring final
What does that have to do with anything?there is a massive difference between the word "May" and "Must".
Eric - I think you'll find that in general the regulations list things which are permitted, not the practically infinite list of things which are not. I think you'll find that the way it works is that unless the regulations say that something is permitted, it is not.I would agree it would not be my preferred method to feed a shed from a ring final, however if I was doing an EICR on one which was already fitted then I would find it hard to quote the regulation number which said it was not permitted.
No, it fails because the final circuit contravenes 433.1.1.The only possible reason to fail it assuming correct size of cables etc would be massive overloading of one leg of the ring.
You really believe that the Iz of 2.5mm² twin & earth is at least 32A? Come on get real.You really believe that you can't supply a shaver socket to BS EN 61558-2-5 or BS 4573 from a ring final? Come on get real.
It's it what the regulations say.I imagine that BAS probably does believe that, since his view is consistent with a literal interpretation of the words of the regulation.
Simple question.If the regulations had been 'perfectly' drafted, such that they ended up sensible and exhaustive, we would not need to have all these discussions. As things are (imperfect), my personal opinion is that a degree of common sense needs to be exercised.
I am dismissing nothing, merely indicating that, in the absence of perfect wording and complete exhaustiveness, there is some scope for varying interpretations.How can you possibly dismiss it as my "interpretation"? ... 433.1.204 Accessories to BS 1363 may be supplied through.... It does not say that anything else may be supplied through..., so if you are supplying something else how can you use its special "deemed to meet the requirements of Regulation 433.1.1" provision?
Exactly. If a cable (and only that cable) originated from a 32A MCB and fed various load(s) via a further downstream 20A (or 10A, or whatever) MCB then we would call it a radial and (subject to various conditions) we would regard it as compliant with the regs. BAS seems to be saying that (regardless of any characteristics of that initial circuit) if one then comes along and also connects the two ends of a ring final to that same 32A MCB, what was the original circuit (now 'a spur from the ring') suddenly becomes non-compliant. That makes little sense to me.This does not apply to the spur which may be run directly from the MCB when it is, in effect, a radial. Are there any different requirements for ring final spurs dependent on the connection point?
Do you intend to claim that the circuit complies with 433.4 and 523.7 for parallel conductors?...but there are two of them.
BS7671, like other standards, gives some general principles, and identifies some of the things that are permitted, and some of the things that are not permitted. The regulations do not state that the colour of the outer sheath of T & E may be pink, but that would not mean I couldn't use pink T & E if I had some.I think you'll find that in general the regulations list things which are permitted, not the practically infinite list of things which are not. I think you'll find that the way it works is that unless the regulations say that something is permitted, it is not.
There is nothing wrong with the wording, and there is no scope for "varying interpretations".I am dismissing nothing, merely indicating that, in the absence of perfect wording and complete exhaustiveness, there is some scope for varying interpretations.
I would suggest that a junction box is no more a thing to be "supplied through" than a crimp, or a solder join, or a wire nutFor example, Appendix 15 includes illustrations of loads being supplied from a ring final via JBs to BS EN 60670-22. Are you suggesting that such is non-compliant with the regulations?
What would you call it then when it really is ignoring what 433.1.1 says?However, accepting that you are essentially correct in what you are saying about what the regulations "actually say", I think that many of us are more interested in the common sense of the situation (what you would call "ignoring the regulations").
Simple question.Do you really believe that it is intended that (despite Appendix 15) JBs are not permitted in ring finals, that switches are not allowed in unfused spurs or that, whilst supplying a load through a 13A FCU from a ring final is fully acceptable, there is some problem with supplying a load from the ring through, say, a 10A MCB? Do you believe that all of those things would deserve a C3 coding ("improvement recommended") in an EICR?
In what way does "supplying a load through" a JB differ from "supplying a load through" an FCU?I would suggest that a junction box is no more a thing to be "supplied through" than a crimp, or a solder join, or a wire nutFor example, Appendix 15 includes illustrations of loads being supplied from a ring final via JBs to BS EN 60670-22. Are you suggesting that such is non-compliant with the regulations?
Given satisfaction of certain conditions, if there is a downstream 20A OPD (or even downstream 20A + 6A OPDs, if CCC is 27A), then yes.Simple question. Does Iz ≥ In work when the cable is 2.5mm² T&E and the OPD is a 30/32A device? Yes or no?
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