Can you test a 3 phase RCD ? HOW ???

Lets take look at some 3 phase RCD testing, in particular a 4 pole RCBO! Didnt know you could get 4 pole RCBOs? Strap in lol. These are in no way training or replacements of. But I am trying to help in my small way. Hope its useful. I know some of you have terrible experiences from training. While that is difficult for some training centres to hear, it is the reality. To many stay silent and thus we get decades of decline. I've tried doing this through official channels this last 4 years. This is a new, more open and direct approach which will become apparent through the coming series of videos. Started gently