AM2 changes on sources for SELV and PELV

You cannot test compliance into a product, it comes from the design. Why we have adopted this standard is ridiculous, is there NO ONE left who can actually read proposed standards and see that they are useful, and in compliance with all the existing ones? I am currently working on another problem, but the same kind of thing has happened, NO ONE has actually understood what is in a draft!

David Stone said:

is there NO ONE left who can actually read proposed standards and see that they are useful

Who is the individual, or department, who would actually "police" this in a reasonable timescale?

The enormous standards making machine Graham, if a standard is referenced in any other standard (and the web is ridiculous as you know well) then the proposed change should be considered by them. In some ways JPEL/64 does well in this regards, but many others don't, and I am not sure that enough weight is given to objections either. It simply needs someone to cross reference everything with a computer, BS7671 is quite good in this respect.

BS 7671 doesn't currently make reference to BS EN 62368-1 for electrical safety, only "along with" relevant parts of BS EN 61558 for EMC purposes (i.e. in that case, a device to the product standard, incorporating a transformer to EN 61558).

Interestingly, this particular issue came to light as part of international standardization work to implement power over Ethernet in the installation standards, so before BS 7671 references it for safety, it has been checked.

Therefore the system you propose is in place and working.

To be fair to the international committees responsible for BS EN 62368 (which replaces BS EN 60950), they did publicise the change of approach when they drafted the new standard ... and therefore I think the disconnect is either:

(a) not addressing (or not appreciating at the time) all of the relevant use-cases, particularly of products to BS EN 62368-3.

(b) the complexity of the approach in BS EN 62368 in terms of "energy levels" of touch voltage and touch current meaning it is difficult to understand and draw parallels with IEC 61140, and I think this is the key issue - too time-consuming to look into too deeply for many, and on the surface it looks OK, so ...?

David Stone said:

It simply needs someone to cross reference everything with a computer

I don't think that would have highlighted this issue. It requires detailed technical knowledge of IEC 61140, IEC 62368 and IEC 60950, along with an appreciation of special installation conditions for some applications and how this affects electric shock risk according to IEC 60479 series.

BS 7671 doesn't currently make reference to BS EN 62368-1 for electrical safety, only "along with" relevant parts of BS EN 61558 for EMC purposes (i.e. in that case, a device to the product standard, incorporating a transformer to EN 61558).

Interestingly, this particular issue came to light as part of international standardization work to implement power over Ethernet in the installation standards, so before BS 7671 references it for safety, it has been checked.

Therefore the system you propose is in place and working.

To be fair to the international committees responsible for BS EN 62368 (which replaces BS EN 60950), they did publicise the change of approach when they drafted the new standard ... and therefore I think the disconnect is either:

(a) not addressing (or not appreciating at the time) all of the relevant use-cases, particularly of products to BS EN 62368-3.

(b) the complexity of the approach in BS EN 62368 in terms of "energy levels" of touch voltage and touch current meaning it is difficult to understand and draw parallels with IEC 61140, and I think this is the key issue - too time-consuming to look into too deeply for many, and on the surface it looks OK, so ...?

David Stone said:

It simply needs someone to cross reference everything with a computer

I don't think that would have highlighted this issue. It requires detailed technical knowledge of IEC 61140, IEC 62368 and IEC 60950, along with an appreciation of special installation conditions for some applications and how this affects electric shock risk according to IEC 60479 series.