First some background. My house (in New Zealand, built in 2005) was fitted with a home automation system called Kristil. The company behind it disappeared around 2011. The system is obsolete and slowly failing, so I’m planning a full replacement.
Kristil had no central hub. Instead, all wall switches talk to each other to control lighting, scenes, alarm, front door lock, etc. It’s a 12V system using Cat5e only and there is no mains wiring at the wall switches.
This is a simplified version of how the system works:
Wall gang switches are wired only with Cat5e (no 230V).
Power + data are daisy chained between the wall switch plates using RJ45 ports 1 and 2.
Port 3 (“triac”) links to a Kristil triac dimmer module at the distribution board (3 lighting circuits per module).
Each wall switch has:
3 push buttons (the top 3 buttons which control one light circuit each)
1 “all off” push button (the bottom button)
Each room also has a 12V PIR motion sensor wired into the same switch plate. Double tapping the “all off” button puts you into sensor mode where the lights will come on when motion is detected.
Each lighting circuit is dimmable by holding the button down.
Some Kristil triac modules are now failing — lights stuck on/off, etc. Time to move on.
For my replacement plan, I’m thinking of replacing the Kristil dimmer modules with Shelly Pro Dimmer 2PM units, controlled via Home Assistant. The big challenge I have found is what to do with the wall switches since they don’t have mains power, only Cat5e wiring. I would ideally like to avoid wifi wall switches because I already have ethernet right there, plus I would feel more comfortable with a hard wired connection.
I wonder if you could use the network cable as a switch extension cable, wire a switch at the wall end and a standard zigbee contact sensor back at the box. That way when you switch on, the contact sensor is open, switch off, contact sensor is off? This way you could use standard light switches in on the wall. You would not have all the dimming capabilities tho.
Look at HaspOne. I have three around the house and love them. They are DIY but could work well in your switch boxes because you can bypass the 110/230V power supply module and provide 5VDC to them through the CAP5.
I think I can use a regular 240v rated momentary switch mech to detect inputs on an ESP32 as long as it’s dry contact only and there’s no 240v connected to it. However, this would mean losing the LED illumination I currently have in my Kristil light switches. I can only send POE safe voltages down the existing Cat5e wiring to power the wall switch LEDs.
The KNX gear looks good but it all seems to be for the Euro style square wall boxes. Really struggling to find anything that will fit and standard NZ/AUS wall box with 84mm screw spacing.
Hm… as European, I have no idea about those NZ standards and which manufacturer provides devices for it. I’d recommend to talk to a local electrician, they should know.
With the HASPOne you 3-D print the enclosure and plate. Here’s one I printed for a 3-position US box. The enclosure itself, mounting ear center-to-center is 3.25-inches, almost exactly 84mm if that is the dimension you are looking at. The box is about 90x47mm.
The instructions say this about the power supply (The MeanWell component in the board image below):
DC Power Option
The [Mean Well IRM-03-5 AC to 5VDC Power supply](https://amzn.to/2UUWGa8) can be substituted with any of the following [Mean Well SLC03-series DC-DC power supplies](http://www.meanwellusa.com/productPdf.aspx?i=786) if you'd prefer a low-voltage DC option. This should be suitable for use over existing Cat5 cables, speaker cables, alarm cabling, etc already in your wall.
This could work well. I could send 12v down one twisted pair to power the PIR sensor and then step that down to 5v to power the HASPone. Unfortunately these don’t pass the wife test. I am told they are too ugly…
On a positive note, after weeks of online research I have found a DC rated momentary switch mech with a led indicator that fits in standard NZ/AUS wall plates. Hager has the 29v WBMLVTN which fits inside their wall plate e.g. the WBSSP3.
I need to get my hands on one to do some testing. If the LED can run properly off 12v then happy days, otherwise I’d have to send 29v down a twisted pair and step that down to 12v to power each room’s PIR sensor.
At least with this solution my house’s light switches will be more typical which is probably a good thing as there’s less to go wrong and it would be easier for someone else to troubleshoot if I get hit by a bus. I could install 1x wall mounted POE tablet or Raspberry Pi with a touchscreen in a central area to interface with the system.
No need. Just get the right Meanwell PSU. The SLC03A-05 in the photo is rated for an input voltage of 9-18VDC.
I keep my page-1 screens pretty basic, but I can view or control just about anything in my Home Network from other pages. My wife loves the one in the family room.
