I'm planning a scheme for emergency stop buttons in the workshop and am considering using the existing RCDs as the switching element. I have a three phase board equipped with a 100mA RCD and a split single phase board with the ring mains on a 30mA RCD. By having emergency stop buttons with two n/o contacts, each with a suitable resistor switching a phase to ground I can introduce a momentary fault current which trips the appropriate RCD but leaves the lighting circuits with power. . Very handy having a button by the exit to ensure everything is off when leaving.
Seems very simple, and I've proved it works, can anyone see any drawbacks to this scheme?
AWEM