Upgrading shower circuit from 6mm to 10mm
- Thread starter zeek
- Start date
Sponsored Links
Undoubtedly, just as I am related to you! However, it wasn't the question about Mrs Waggon to which I was responding - my response related to "why am I even replying to this!!!"Yes, you are related to Mrs. Waggon - somewhere in the past.
Kind Regards, John
I think you may miss the point. It's not a cause for argument but, rather, a 10V difference which has been know to allow some people to 'get away with' (in terms of compliance with regs) a lower CSA cable for a shower supply. The fact that supply voltage may vary by as much as 36.8V doesn't concern the regs - design calculations assume a 230V supply.
Kind Regards, John
Sponsored Links
Mmmm. I am a little irked by the term 'get away with' implying that it is somehow 'not quite right'
We've been here before but - it seems perfectly obvious to me that as the nominal voltage is 230V and that is what must be used for determining such values as design current then only values which relate to 230V should be used.
When the nominal voltage was reduced the maximum Zs tables, for example, were adjusted by a factor of 230/240 therefore ensuring that the overall conditions remained the same.
I do not know why CCC was not similarly adjusted .
I assume (?) that there was enough margin in the figures that it was deemed unnecessary.
On the other hand if, as a lot of people do, the 240V wattage is now just divided by 230, this has the effect of raising the design current value - admittedly making the installation even 'safer'.
I cannot imagine this was the intention when reducing nominal voltage and would have thought those in charge would realise the outcome of the change so i will maintain that as 230V is to be used then 240V values are not.
I realise that - but you you'll have seen what happened when I also tried to lighten the Saturday night mood a few posts back
Kind Regards, John
It was perhaps not the best phrase to use - but, unless/until the IET reveal the 'safety margins' they have built into their figures, it's difficult to know whether 'compliant' cable sizes are necessarily 'good electrical design practice' - given that it is an inescapable fact that a cable deemed by the regs to be 'safe' after the change in nominal voltage may not have been deemed to be safe prior to the change. As you go on to say ...
That could well be the reason but, if so, it must mean that they decided that a smaller safety margin was acceptable after the change than before it. As I said, without knowing the magnitude of thsoe margins, it's difficult to make an objective judgement.
The situation is, of course, further complicated by the facts that (a) many manufacturers persist in quoting 'wattages' at 240V (presumably to make their products sound 'more powerful' than they would if the 'wattage' at 230V was quoted) and (b) that I suspect that most consumers have supply voltages closer to 240V than to 230V.
Kind Regards, John
There is, of course, the 'seemingly more powerful' argument and the fact that one manufacturer would not want their products viewed as less powerful if other manufacturers did not reduce their figures.
However, some manufacturers do quote both values ( 240 & 230 ).
Not necessarily on the box but on the actual parts.
It would be difficult to attribute a reason for this if it were not the value to be used, would it not?
Exactly. Much as I am no fan of excessive regulation, I think there would be a case for them to be compelled to quote power at a 'standardised' voltage (presumably the nominal supply voltage), not the least so that consumers could make 'like-for-like' comparisons. Mind you, in this day and age of 'energy awareness', I'm not even sure which way round it now works in many people's minds - is 'more power' regarded as better or worse?!
Which value would that be? If they quote two values, I don't see how that would aid people in knowing which of the two is 'the value to be used' - they would have to look elsewhere (e.g. to the regs) to discover that, wouldn't they?
Kind Regards, John
I meant the 230 - otherwise why would they quote it?
Not for the general public - for the electrician.
Presumably why its printed on shower engines, for example.
One can but speculate. It could, for example, be for 'international' reasons - after all, 240V has always been a pretty inappropriate figure at which to quote power for most non-UK countries. Are you sure that those shower engines did not quote a power figure for 230V (or maybe 220V) before the change in nominal supply voltage.
Kind Regards, John
Oh. I can't remember.
I would think 220 better for EU.
Plus it's in English.
What is the distinction between 'Supply' and 'Product type'?
I would think 220 better for EU.
Plus it's in English.
What is the distinction between 'Supply' and 'Product type'?
What else?
Goodness only knows - not a contender for the 'Clear Label Award'. It almost sounds as if it 'wants' a 240V supply!
Kind Regards, John
I mean that it's not just numbers - hardly appropriate for Europe.What else?
Have since thought more about the reducing of nominal to 230V and CCC.
Perhaps the regulation writers also thought that current would increase with lower voltage so there would be even greater safety margin.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
