Was going to ask a similar question. Done my 2392, read myOSG & GSN 3 and watched a vid from the ‘learning lounge’ on the same subject.
I’m kind of confused about breaching EWR on live testing. Onan earth loop test on final radial circuits (i.e. lighting), it’s recommended to carry out the calculation method for Zs (=Ze+(R1+R2)), so as not to breach EWR.
However, to do a RCD test on a RCBO radial (i.e. live test),you could only do that at a lighting point, exposing live parts or at the CU (only testing the device), but again with the cover removed and live parts exposed?
As regards IR testing of a RCBO, I see some manufactures state their RCBO can withstand IR testing, but can give false readings, so should be disconnected? I've seen other instructions to disconnect the ‘earthfly lead’ and test each circuit (with RCBO turned off) independently.
Being picky I know, but having my assessment soon, so I want to do it correctly.
Apologies paddyscouse for hyjacking your thread, but think it is asking the same question.