Single pole rcbos with a N+E fault can take out the upfront S type.I have installed this arrangement many times over the years and never had an issue with accumulated leakage on a domestic installation to that level.
I have however come across this issue on dairy installations where the vacuum pumps have been upgraded and changed to vfd driven. The vfd's were causing the milking shed to trip and shut the whole lot down!
I also came across where next doors' induction hob was tripping the up front s type in the other house.
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