Hey guys,
I try to find out what exactly the functions of the Nuki Opener doing, as the support could not answer the question.
Purple/Blue: should work as a relay and just close the circuit
But if it’s going to bell suppression it’s different. I thought the green or yellow wire will just shut off if the suppression is activated but this is not the case cause it needs the ring signal of red/black.
If yellow or green is connected to my bell (8v ac), the bell is not working properly anymore cause the voltage is changing, also there is a strange behavior with the suppression:
If suppression is activated there is no ring detection, suppression can’t be deactivated and the nuki app is crashing sometimes. I have to disconnect the whole cable, red/green or purple/blue to get it back on track.
Seems there is a problem with the 12v ac from the door opener and the 8v ac from the bell.
Support changed things but couldn’t tell me what they did and send me here 
Best