Triggering Floodlights with Volt Free Contact Closure

    Hi,

    I'm looking to use the new Shelly Pro 4PM to switch several LED floodlights and want to trigger the lights from the output of a CCTV NVR which has volt free N/O contact closure outputs which can be set to trigger when an event is detected.

    Can anyone advise how this contact closure could be integrated into Shelly to trigger the lights to switch on. I've looked at the Shelly Uni and this had two inputs which might work but would appreciate any input from someone who has setup a similar control system.

    Zitat

    I've looked at the Shelly Uni and this had two inputs which might work but would appreciate any input from someone who has setup a similar control system.

    Unfortunately, I’ve no similar control system running. Hence, my advice will be more or less on a theoretical base. Sorry!

    Assuming the LED floodlights shall be supplied with mains voltage, the Shelly pro 4PM is not an ideal device to solve this issue: Because it’s inputs are NOT separated from the mains supply! Further assuming the contacts of the CCTV NVR are suitable for low voltage/low current only, I would suggest one of these two arrangements:

    (a) Use 4 Shelly plus 1 instead of a single Shelly pro 4PM. You will lose energy metering but you may connect the inputs directly to the NO contacts of the NVR and switch the floodlights by the contacts of the Shellies. The Shellies must be supplied by an extra 24V DC power supply - one supply is sufficient for the four, assuming the power supply can deliver 1A or more. Please have a look at the ‘Lexicon’ to find the appropriate diagram!

    (b) If you persist on using a Shelly pro 4PM, you must isolate the switch contacts of the Shelly from the inputs. This can be done via an additional Shelly i3: It’s inputs have to be connected with the NVR outputs. The Shelly i3 must be supplied by a 24V DC supply. Commands between Shelly i3 and Shelly pro 4PM are interchanged via DDD communication. By this means, both Shellies are separated electrically. You will find diagrams for both Shellies in the ‘Lexicon’.

    „Habt Geduld. Alle Dinge sind schwierig, bevor sie einfach werden!“ (aus Frankreich)

    „Nothing in life is to be feared, it is only to be understood.“ (Marie Curie, 1867-1934)

    „Es reicht nicht“, rief Schiller, „Gedankenfreiheit zu fordern, man muß auch denken können, sonst fordert man Gedankenlosigkeitsfreiheit und die ist die Freiheit zur Dummheit, welche wiederum die schlimmste Unfreiheit überhaupt ist!“
    (Aus „Besuch aus Weimar“ von Gert Heidenreich, Schriftsteller, *1944 in Eberswalde)

    Einmal editiert, zuletzt von thgoebel (21. Oktober 2021 um 19:34) aus folgendem Grund: Addendum: Power supply added to proposition (a).

    Thanks for the reply, much appreciated.

    Your thoughts are what I feared and it seems that Shelly doesn't really have a good interface for this scenario. What's really needed is a simple Shelly Input unit which accepts dry contacts for signalling Shelly relays.

    The suggestions to use Shelly Plus 1s would work but it's not ideal. It's a possibility though so I'll give it some further thought and research.

    Many thanks again.