Opener with Ensign 3407

Am I able to connect the Opener to this Ensign 3407 intercom? I have looked at the Nuki Opener unknown intercom guide and assume that I have an analogue intercom. I have attached photos and the intercom schema/system-wiring.

Handset Connection Diagram:


Update: Managed to successfully install the Opener with the Ensign 3407. Used the unknown intercoms guide. The intercom is Analogue and the basic setup without doorbell suppression was used. I assume the setup with doorbell suppression will work as well.

Ensign 3407 Connections:

C: (Call) Yellow Cable
L: (Lock) Blue Cable
-: (Negative) Purple Cable (Ground)

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Hi James, thanks for your instructions which I found helpful. Have you by any chance, managed to get the audio working?

Thanks in advance.

Hi all, I seemed to have found my solution, although it didn’t seem to work before. One thing of note, even though my buzzer wasn’t activated, I was still able to speak to whoever was at the intercom.

1: Red cable - Loudspeaker
2: Orange cable - Microphone
-: Black cable - GND (Ground)

Hi @sureshot,

With the Loudspeaker & Microphone cables connected are you able to speak & listen through the Nuki Opener App?

Hi @James1 - Thanks so much for working this out. Your post is the only one I’ve found online that talks about how to hook up an opener to the Ensign 3407. I am actually trying to connect it to a Ring Intercom, not the Nuki, but I’m hoping the principles will be the same.

Where did you get the functions of the Ensign connections from? There is a generic option for the Ring too but the terminology is not the same and I’m not sure where to connect the Common for example.

Also have you got audio working too? Is that using the setup from Adrian (ie. 1 is loudspeaker and 2 is microphone)?

Hi @stefanroberts

I no longer use the Nuki opener as they never updated the app to allow for audio/microphone functionality. I built my own solution using a Raspberry Pi with a Relay HAT along with an ADC and a 3.5mm to block terminal audio jack.

I got most of the functions by trial and error, as well as using a multimeter to identify the behaviour of the various microswitches and hook switch.

The common/GND on the Ensign is the “-” terminal

“C” is for Call (The hook switch changes this depending on its open and closed state I had to connect a relay to this terminal to simulate the handset on the intercom and being picked up.

“L” is for Lock

“1” and “2” I believe are for audio, I think “1” is Speaker and “2” is Mic

I didn’t use the 1 and 2 terminals for audio instead I connected my 3.5mm audio cable from the Pi to the mic wires to send audio, I matched the impedance using 2 x 100-ohm resistors and got clear and loud audio at the main door.

So helpful, thank you @James1. I will experiment and see if it can work. One final question (and forgive my ignorance but), is it safe to just insert the cables into the terminal board or do I need to switch off the power somehow first?

No problem. Yes, it’s safe to insert the cables with the power on.