ProMbrooke:

gkenyon:

And finally, we've openly permitted RCDs to deal with disconnection time not only in the UK, but also in CENELEC countries, and across IEC, for many years - at least 13 years now in the UK with current wording, but even further back in time being realistic, as there was a sort of "permissive" approach towards RCDs for automatic disconnection towards the later 16th Edition of the Wiring Regulations (BS 7671:2001 and perhaps earlier).


Is there any evidence that modern RCDs are failing to provide the protective function?

Maybe I'm wrong, but I read somewhere that RCDs can not be used to achieve disconnection in a TN supply where high EFLI is present. Could be wrong here.

Definitely.


411.4.204 now permits RCD to perform the ADS function full stop. Overcurrent protection (overload and fault protection) is still required because of course the RCD can't provide that. There is no longer a "where high EFLI" - the RCD can perform the function for protection against electric shock now.

ProMbrooke:

gkenyon:

And finally, we've openly permitted RCDs to deal with disconnection time not only in the UK, but also in CENELEC countries, and across IEC, for many years - at least 13 years now in the UK with current wording, but even further back in time being realistic, as there was a sort of "permissive" approach towards RCDs for automatic disconnection towards the later 16th Edition of the Wiring Regulations (BS 7671:2001 and perhaps earlier).


Is there any evidence that modern RCDs are failing to provide the protective function?

Maybe I'm wrong, but I read somewhere that RCDs can not be used to achieve disconnection in a TN supply where high EFLI is present. Could be wrong here.

Definitely.


411.4.204 now permits RCD to perform the ADS function full stop. Overcurrent protection (overload and fault protection) is still required because of course the RCD can't provide that. There is no longer a "where high EFLI" - the RCD can perform the function for protection against electric shock now.