LED Lights in bathroom over shower

[JohnW2]

But seriously, they are unambiguous (although I still can't find the basic definitions, that's because I've other things to do) but they are not used in the sense of, for example "voltage shall not exceed ELV" but more like "when protection against electric shock is done by the use of ELV, the voltage shall not exceed X volts".

I have absolutely no problem with that phraseology - they are merely restricting themselves to a subset of ELV in a particular application. That's very different from producing a 'local' (numerical) definition of ELV.

Yes, it does seem that there are people who think they can be given a numeric limit that will be adequate in all applications, but engineering is not that simple. They are "IEC-dictated strictly numerical definitions of ranges of voltages", but within those ranges the responsible Technical Committee will select a value that is appropriate for the product/application for which they are responsible.

Again, that's totally reasonable. As above I have no problem at all in a Technical Committee specifying a (numerical) voltage range. for their application, which is narrower/lower than the IEC "ELV" range, so long as they do not 'redefine' ELV for their purposes.

It seems that, after a lot of discussion, we have got to the point at which it is fairly clear that there is no problem. If I now understand you correctly, when you challenged my statement about 90V DC being ELV, by saying that, in the context of machinery, the upper limit of ELV would be 50V or 60V DC, I suspect that you did not actually mean what you wrote - it sounds as if what you really meant is that, in relation to machinery, if protection against shock was achieved by the use of ELV, then the highest DC ELV voltage permitted was 60V. Is that what you meant? If so, and had you actually written that, we would both have been spared a fair bit of typing

Kind Regards, John

 

[stillp]

Ooops! In my world (machinery) ELV limit is 50V ac or dc.

Aha

... but this is then getting even more ridiculous, isn't it? It's bad enough for the official terminology to be confusing to, and not understood by, most of the population, but you now appear to be saying that the definitions of that terminology are not even consistent across industries!

Kind Regards, John

John, what I wrote was the ELV limit for machinery. I did not say anything about the definition of ELV, did I? You're the one who keeps referring to "redefining" ELV.

 

[JohnW2]

John, what I wrote was the ELV limit for machinery. I did not say anything about the definition of ELV, did I? You're the one who keeps referring to "redefining" ELV.

There clearly was a misunderstanding. Yes, you said that "the ELV limit" for machinery was 50V DC (and subsequently corrected that to 60V DC). However, that was in response to my having said that "ELV goes up to 120V DC". I don't think I can blame myself too harshly for having thought that your "ELV limit" and my "ELV going up to" were both referring to the top of the ELV range. However, as I've said, I now understand that you meant something like "the limit for machinery within the ELV range" - so the misunderstanding has now been resolved!

Kind Regards, John