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.
That's correct. 5x for additional protection and 1x for fault protection
Why would you test at 1x for fault protection? L-PE faults will always have a significantly higher current than IΔn (typically least 4.6x if the installation complies with minimum TT requirements - normally much higher) and the times allowed for BS EN RCDs at 1x (e.g. 300ms) are insufficient for TT disconnection time on most final circuits where 0.2s is required.
That's correct. 5x for additional protection and 1x for fault protection
Why would you test at 1x for fault protection? L-PE faults will always have a significantly higher current than IΔn (typically least 4.6x if the installation complies with minimum TT requirements - normally much higher) and the times allowed for BS EN RCDs at 1x (e.g. 300ms) are insufficient for TT disconnection time on most final circuits where 0.2s is required.
