Originally Posted by paulfg
thanks pj just wasnt sure as the leg is 240 volts to earth not 120
If you measure the lines of 240V power there is 240V from black to red. Then there is 120V from either black or red to the white (neutral). Also there would be 120V from either black or red to ground.
WAIT, WAIT... I just checked and you live in Greece. Completely different situation. Wow, I gald I looked. Your power delivery is very different than here.
For your setup you could place 4000 ohms of resistance in your E-Stop circuit. That would limit the current draw to 0.06A for your 240V power to equipment ground. The 0.06A should be Ok for tripping the GFCI but it might be a good idea for you to check out the trip specifications of your particullar GFCI breaker.