I've noticed some changes to TABLE 537.4 (the one that lists the suitability for Isolation/Emergency switching/Functional switching for lots of devices). Some changes seem to be a 'tidy up' (e.g. devices that previously said No to isolation but Yes to Emergency switching, now say No to both - which makes sense as the requirements for emergency switching have included providing isolation for a while now) - but some other changes seem less obvious and may have more consequences...
For instance, previously we could use BS EN 60309 (commando) sockets up and including 32A for functional switching - now that limit seems to have been reduced to 20A. Does that mean that 32A sockets will now have to have an interlocked switch (or equivalent means) to prevent them being disconnected or connected under load? (as we usually see for higher ratings) Is there then a suggestion that existing unswitched 32A sockets are no longer suitable for continued service?
- Andy.
