apologies if you are already aware of this but with respect to the x5 or greater test current introduced in the 18th, Hager have advised that their RCBO units are manufactured to the 2017 amended version of BSEN61008/9 which permitted disconnection within 40ms at 250mA. Thus they advise testing at x 5 on both sides with the instrument set for 50mA on the variable range.
BS EN 61008 and BS EN 61009 both require RCDs to trip at 300ms or less at X1 I delta n. That is the product standard for the devices. That standard is set out in Table 3A of Appdedix 1 of BS 7671.
BS 7671 does not have a specific regulation for RCD testing test currents or times.
When inspecting and testing an electrical installation it is generally either to verify that the requirements of 7671 2018 have been met or that the installation is safe for continued use. Whilst during initial verification one must confirm that the installation equipment meets the relevant product standard, there is no particular requirement to do that by test. For example, the fact that a BSEN 61008/9 30mA RCD/RCBO fails to trip at x1 but does operate within 40mS at 250mA will not breach the requirements of BS7671 2018. It would be a moot point to determine that any failure at x 1 was a breach of the product standard as the device would have been subject to an in-service test with all the uncertainties that entails rather than the more clinical approach taken during production testing.
One would have thought that GN3 would have clarified matters but instead it pursues the now de-railed labour party policy of constructive ambiguity. However, it does make clear that where an RCD is not provided for additional protection and that circuit breakers installed with it operate in accordance with Chapter 41 of BS7671 2018 then time-testing is not essential for the RCD. That would imply that there is no reason to test an RCD for compliance with its standard. You can if you wish but if it fails, then in my opinion it is nothing more than noteworthy.
apologies for the aside, but I love the smiley moments in life where least expected...this is one for me from @lyle "...but instead it pursues the now de-railed labour party policy of constructive ambiguity.." re: GN3. :-) :-)
