Electric advice

guinnesstomato

Hi some advice needed if you can! Just got a new sprite musketeer eb and on first outing by mistake put a kettle on with the microwave and blew the electrics however it didn't trip the vans rcd but the sites rcd on the electric post. It  happened twice and
I can't work out why it didn't trip the caravans rcd ( a pain and embarrassment having to get the warden twice). On my old swift challenger when this happened the rcd in the van would trip and the only hassle was lifting the cushion to reset the rcd. Anyone
have any ideas could my vans electric unit be faulty? Help if you can!