I found a manufacturer of RCD components. Not RCD's but the things that are inside them.
I thought some things were interesting, so I'll just throw a link in:
http://www.westernautomation.com/pages/generics.htm One button RCD --> will that lead to a one button RCBO?
ASIC based RCD --> next step is a full microprocessor --> arc fault detection should be easy to incorporate
