I have posted a piece here which is also on the TT topic, but is more general and I think a new thread would be better. Your voice is heard. See below.
That seems to be just part of huge re-write of section 536 for the 18th Ed. I can't help wondering if such vast changes don't originate with JPEL/64 but as just copies of chunks of some upstream standard (IEC/HD 60364 or possibly bits culled from BS EN 61439 itself) - in the same way that A721 would seem to have been plagiarised from BS EN 1648. If JPEL/64 works anything like any committee I've known it would have taken them decades to come up with so many words themselves. Even the 200 numbering only means it's UK specific, not necessarily JPEL/64 origin - many EN standards have country specific conditions and appendices so it might just be a copy-down from elsewhere. Certainly JPEL/64 should have yea/nay'd it in principle, but if it is derived from some 'higher' standard their choices might have been limited.
In any even the lack of obvious overload protection for RCCBs in (especially split load) CUs was a bit of an anomaly - we'd never put a 63A device in the middle of a 100A circuit if we were just wiring discrete separately enclosed devices together by normal BS 7671 rules. It was only previously acceptable because the whole CU assembly was covered by other standards and so outside the scope of BS 7671 (other than the choosing of it). Even now there still seems to be a get-out clause of following manufacturer's instructions (so presumably in theory they could still specify that a 100A fuse is OK for their 63A RCCBs if they want - even if BEEMA members choose not to do that).
I guess another consideration is that the nature of loads on CUs is changing - a lot more will be getting EVSE and heat pumps connected to them which are likely to have rather different characteristics (larger currents and long durations) compared with many traditional domestic loads which tend to be either low current or short duration (off-peak storage heating being the one obvious counter example, but that's come with warnings about loads on CUs for donkey's years). Manufacturers (incl. BEEMA) might (reasonably) be trying to position themselves to avoid anticipated future problems.
That seems to be just part of huge re-write of section 536 for the 18th Ed. I can't help wondering if such vast changes don't originate with JPEL/64 but as just copies of chunks of some upstream standard (IEC/HD 60364 or possibly bits culled from BS EN 61439 itself) - in the same way that A721 would seem to have been plagiarised from BS EN 1648. If JPEL/64 works anything like any committee I've known it would have taken them decades to come up with so many words themselves. Even the 200 numbering only means it's UK specific, not necessarily JPEL/64 origin - many EN standards have country specific conditions and appendices so it might just be a copy-down from elsewhere. Certainly JPEL/64 should have yea/nay'd it in principle, but if it is derived from some 'higher' standard their choices might have been limited.
In any even the lack of obvious overload protection for RCCBs in (especially split load) CUs was a bit of an anomaly - we'd never put a 63A device in the middle of a 100A circuit if we were just wiring discrete separately enclosed devices together by normal BS 7671 rules. It was only previously acceptable because the whole CU assembly was covered by other standards and so outside the scope of BS 7671 (other than the choosing of it). Even now there still seems to be a get-out clause of following manufacturer's instructions (so presumably in theory they could still specify that a 100A fuse is OK for their 63A RCCBs if they want - even if BEEMA members choose not to do that).
I guess another consideration is that the nature of loads on CUs is changing - a lot more will be getting EVSE and heat pumps connected to them which are likely to have rather different characteristics (larger currents and long durations) compared with many traditional domestic loads which tend to be either low current or short duration (off-peak storage heating being the one obvious counter example, but that's come with warnings about loads on CUs for donkey's years). Manufacturers (incl. BEEMA) might (reasonably) be trying to position themselves to avoid anticipated future problems.
