UFH Control

Here's a question - anyone have any bright ideas on how I can integrate my Underfloor Heating with CBUS ? (I also have Comfort).

The Aube sensors have a pilot wire system that allows it to control the thermostats per room (they are all connected via this pilot wire).

To control them, there are particular signals that are sent - so a relay isn't going to work.

Page 1 on this manual shows the type of signal that needs to be sent in order to control them - http://www.aubetech.com/manuel/2/TH134.pdf

Looking for inspiration !

Thanks

 

Never used the system but from reading the manual may be possible depending on the signals - and two relays.

This assumes that the waveforms on the signals table are continuous (ie, only one cycle is shown - you would need to test this is the case with a scope on the output). It also assumes that you want the same function for all rooms (as the manual doesn't seem to reveal what signal is use to select the zone).

In simple terms, generate the same signal for state 2 (continuous waveform), connect 2 parallel cicruits consisting of a diode and C-Bus relay contact in series (one to clip the bottom of the waveform, the other to clip the top) through to the pilot wire. Then by controlling the two relays and the period of time at which they operate you can replicate each waveform.

If you don't need the Aube controller provided, use it as your signal generator (configure the unit to be in the 2nd state as per the signal table and leave it that way).

Not sure if this would work in practice (theory always sounds good), but this is what I would try and it would be simple to test.

Also need to consider that for the last two states would be cycling the relays quite often (over 100,000 times per year if kept in that state continuously, again assuming the signals need to be continuous rather than pulsed to change/maintain the state)

Hope this start the inspiration flowing!

 

From looking at the PDF you supplied,

it looks like they recommend that to control it from a Home Automation System, that you should use a relay to simply power the Live (Active) of the heating circuit directly, bypassing the control system completely.

Wouldn't using a C-Bus temp sensor and a C-Bus relay controlling the heating circuit do the job? or do you already have all the heating controllers set up?

To control your heating system through the "Pilot" line would be beyond the scope of any existing products, and would require a large amount of custom manufacturing and programming to interface with C-Bus, and I doubt it would be worth the effort.


Best of luck

Darpa

 

Relays

My understanding was that the Thermostats vary the voltage to control the heating - ie full on to get going, but thereafter doesnt just switch on and off - keeps it ticking over by varying the power.

Hence to try to control the Pilot wire as that is the "intelligence" they have..

G.