Replacing Finder 20.28 with Shelly Plus 2PM wiring question

    Hi everyone!

    (feel free to respond in german, I understand it quite well, but my written german is really poor...)

    In my apartment I have many rolling shutters. I've successfully built in Shelly Plus 2PMs for several that are controlled by 2 buttons (up/down). But I also have 3 rolling shutters controlled by a single switch/button each. So, you press the button, the shutter goes down. You press it again, it stops. Press it again, it will go up. Press again it stops. Press again, it goes down, etc. The switches are connected to Finder 20.28 relays in my switch box (again, one for each). I intended to replace those Finder units with Shelly Plus 2PMs too since I want to make controlling them a bit more logical (the buttons/shutter locations is a bit of a mess for those three), and I am now trying to figure out how to do the wiring. And here is where I am getting a bit stuck because what I expect to see in terms of wiring, and what I actually see appears to be different.

    I looked up the documentation of the Finder 20.28 and there I find the following diagram:

    Screenshot 2023-03-21 at 09.35.50.png

    So what I think I understand from this diagram is as follows: I expect to see it wired up so that the bottom outputs (2 and 4) are going their separate ways, to the motor(s) of the rolling shutter. So, between 2 and A2, and 4 and A2 are the motors. This is what I would wire up with terminals O1 and N, and O2 and N respectively on the Shelly. 1 and 3 might be looped and tied into a shared lead going somewhere, but don't have to be. Between 1 and A1, and 3 and A1 are the switches. So I expect to hook those up to S1 and L, and S2 and L respectively. Now, given that there's only a single switch, I understand that there might be some oddities here, but I thought I would figure that out...

    So, now I open the switchbox and look inside, and... The reality does not appear to match up with my expectations:

    IMG_1482.jpeg IMG_1483.jpeg

    2 and 4 are looped together where from the Finder documentation I expected 1 and 3 to potentially be looped together. I am also trying to wrap my head around the blue wire out of the A1 terminal, since I would not expect that there.... Could anyone give me a bit of a nudge in the right direction here? Am I understanding the Finder diagram incorrectly, and could you wire up the relays 'the other way around', as it appears to me is the case here?

    Thank you all :)

    Rene

    Die Schaltkontakte sind potentialfrei, man kann sie also auch so wie bei dir anschließen.

    1 und 3 dürfte die Ansteuerung von hoch und runter des Rolladenmotors sein.

    2 und 4 ist die Netzspannung, die zum Rolladenmotor geschaltet wird.

    A1 und A2 müsste einmal Neutral und einmal der Geschaltete deines Rolladentasters sein. Da hier die gleiche Aderfarbe verwendet wurde, muss man durch messen oder nachverfolgen der Adern feststellen, was Neutral und was Geschalteter ist.

    Also, wenn ich das gut verstehe fur meinen fall:

    • 1 und 3 auf die Finder wurden auf die O1 und O2 von ein Shelly Plus 2PM gehen
    • 2 und 4 auf die Finder wurde L auf die Shelly Plus 2PM sein.
    • Und dan A1 auf S1, oder A2 auf N, oder A1 auf N, und A2 auf S1, und das hangt ab von welche von A1 und A2 die geschaltete ist, und welche die neutral

    Habe ich das so gut verstanden?