Thanks for all the input here! I combined the info here with the examples of using the RED-114Y in the other threads (Elcom BVF-510 and Elcom i2 Bus (BVM-100)).
Here’s a working setup with the BHT-200, RSR-200 and RED114Y. No soldering or modification required.
Everything neatly in a junction box:
Ring detection, opening, and ring to open works. Ring suppression doesn’t work of course , but I plan to simply disconnect the BHT-200’s speaker wire and use the Nuki as the bell.
Basically:
- Replace the BHT-200’s in-built relay with the RSR-200
- Use the RSR-200’s ring detection - connect the Nuki yellow wire to the first K, bridge the second K to the second a.
- Use the RED-114Y to open the door - connect Nuki’s blue and purple wires to the CTRL-IN inputs, and the X X to the bus (RSR-200’s a and b).
This diagram should be pretty clear:
Here’s a photo of the setup:
