As I understand it, that third wire only links some contacts together ... it there's continuity in one detector, they all sound off.
Yes that true John but if you have third wire interconneted and also the netural line as well as common return [ i have little trouble to grasp this idea how it work ]
but for hot's line it can be on common or diffrent phase or leg but i am sure but not excat answer for this one but i am thinking out loud that both red [ interconnection ] and white wires to actavie it
Merci , Marc
