Detect 24vdc

[karmic hornet]

I have some dumb ultrasonic motion sensors that run on 24vdc and have common/control wires that trigger a relay to turn on some lights (relay is a hubbell UVPP). I'd like to detect when the sensors see motion in home assistant.

Hubbell makes an auxiliary relay that takes the 24vdc signal and provides a dry contact that I could then connect to any number of smart dry contact sensors. However I feel like this should be doable with a single smart device.

I'm not sure if a typical smart dry contact could handle the 24vdc, so maybe I need something that can just take the 24v on an input.

Does anyone have any suggestions for how best to handle this?

I was hoping to just add something to the existing solution to provide the state, but I suppose I could try to replace the power pack/relay or motion sensors. I'll leave those as plan b for now.

Zwave or Wi-Fi preferred

Thanks!

[karmic hornet]

I kept researching and learned more. I think the shelly 4i dc can do it. Or Shelly wave version

[mossy loom]

https://www.thesmartesthouse.com/products/zooz-z-wave-long-range-low-voltage-xs-relay-zen58-800lr maybe reading more, it says no voltage on the switch terminals so just checking for closed circuit

[karmic hornet]

Based on this diagram the i4 DC can handle some voltage on the inputs

[proud knot]

I would personally go for one of the esp relay/optocoupler modules e.g. https://www.aliexpress.com/item/1005010291526026.html

The shelly might not work, depends on your sensors. It is expecting the sensor/switch to connect to 0v when it is on - whereas your sensors might output 24v instead

[karmic hornet]

Thanks! I was worried about that but the diagram above from Shelly leads me to think it would be ok. I can always ask them too. I'm wonder if I can find a version of that with a case. Was wanting something off the shelf.