The 1x test is no longer a requirement but could of course be carried out. ...
The problem I see is that as the advice as written it may well be possible to have an RCD that does meet 40ms at some arbitrary high current but would not do the required at 30mA.
I have a sneaking suspicion that what was lost in translation should have been more like
40 ms when tested at currents equal to AND higher than.
So that would mean that it must make 40ms at 5 times, and must not respond more slowly at any higher currents. It is hard to see why that failure mode would occur however, and that is sadly not what it says.
The problem I see is that as the advice as written it may well be possible to have an RCD that does meet 40ms at some arbitrary high current but would not do the required at 30mA.
Something must have been lost in the translation.
Testing at 250mA would not be RCD x 5, would it?
AJJewsbury:
Something must have been lost in the translation.
Testing at 250mA would not be RCD x 5, would it?
That's the point - it seems the standards have changed so that 5x IΔn is no longer the requirement. You might have noticed that all the requirements for a 30mA RCD used for additional protection to have 'an operating time not exceeding 40ms at a residual current of 5 IΔn' vanished completely from the 18th Ed - the requirement is simply for a 30mA RCD now. We seem to be discovering why....
I'm trying to imagine why such a change would have been thought a good idea - after all we certainly have the technology to achieve 40ms at 150mA - maybe it's to allow the RCD to ignore the sort of transients that can lead to 'unwanted tripping' or some such.
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