HVAC - CBUS Capability

G'Day All,

I'm doing a complete rennovation of my house, and as you probably guessed, CBUS will play a large part of the finished product.
My background is in Refrigeration/Air Conditioning, and I'm a qualified sparky as well (also have spent some of my career in the A/C controls/DDC side of the business). As such, my HVAC control at home will ideally be run using the nice Saturn finish Thermostats.
I've read the installation instructions, and for straight forward operation, it's very simple.

Given my background, I'm after a less than straight forward installation, it would also need to be fairly sophisticated to justify the cost of the CBUS gear.

My first question is, can I have background logic running, that uses temperature data with just the thermostat(s) and digital relays?

What I would ideally like to acheive, is a domestic version of an economy cycle for the A/C as well as a few other bits and pieces.

For example, using the CBUS toolkit, could I write "programs" with IF, THEN, ELSE statements to control all the digital outputs? (all A/C operation functions, compressor, Rev Valve, I/D Fan, damper motors etc etc...)
If so, then my ability to control things just increased massively.

 

Further to my post above, some information that may be useful in answering my question.
The cbus setup I plan on having (apart from two ducted A/C systems with Saturn t/stats) is as follows:

• 3 x 8 Channel, 1amp dimmer modules
• 2 x Relay modules (digital, or on/off control)
• 3 x Blind controllers
• DLT Switches, plus Saturn range wall switches.
• 2 x Ducted A/C (one upstairs, one downstairs) with Programmable CBUS thermostats.
• Note that there are no touch screens... don't know if this matters when it comes to programmable logic.
• Note that the entire house will not be CBUS, only the public/living areas (and pool lighting etc...) bedroom and private zones will mostly be traditional wiring.

Not sure if the above information is relevant to my programmable logic question or not, but just in case, there it all is.

I'd also like to hear of other peoples installations, to see exactly what they are managing to acheive with CBUS in the home. It's very exciting technology, and I think that an enterprising person could make it do a lot of work, prividing of course that there was some background logic able to be applied as with a commercial BMS, or DDC system.

 

I wasn't aware that there is a Saturn Thermostat. I could be wrong though...

You can have logic in a PAC or Touch Screen which can read the temperature from a C-Bus thermostat or temperature sensor and control relays.

The C-Bus Thermostat supports a "set-back" setting. I am not sure if this is the same as your "economy cycle".

You can't write logic code with the C-Bus ToolKit. You can do it with PICED for use with a PAC or Touch Screen.

The C-Bus Thermostat does have some very sophisticated control algorithms already in it. If at all possible, you should use the control functions supported by it so that you don't have to "reinvent the wheel".

 

Thanks Darren,
By Saturn finish, I mean the white finish stats

So without a Touchscreen (not sure what a PAC is just yet), I can't control any extra gear based in temperature readings.
No worries, I'll add the MkII B/W touch screen to the shopping list... off to the minister for finance (aka, the Wife) for capex approval

All I really needed to get one of thoise, was an excuse, now I have one

 

Hi Brad, PAC is short for Pascal Automation Controller.
The very simplest description of it is that it is a unit dedicated to running logic for the C-Bus network.

You can find the product page, as well as a much better description, at:
http://www2.clipsal.com/cis/technic..._and_accessories/pascal_automation_controller

Darpa

 

Thanks for the information guys, I really appreciate it.

Now that you've given me an excuse (and my neighbor suggests that setting up the touch screen "aint' no thang", I'll be getting the MkII screen with Logic.

Regarding the set-back and time schedule programming for the stat, I agree that it's got a bit in it, but I want to do other work based on ambient temp, season, light level etc etc...

For example, (plain english code statement)
if RoofSpace Temp >25 AND "Season" = "winter" THEN
Energise relay (pumps free, filtered warm air from roof space to house)
ELSE
"Do nothing"
END IF

I also want to use the digital outputs to control different systems, based on the information being read by the thermostat and remote sensors. For example, I have two ducted reverse cycle air conds, plus a zoned gas ducted heater (sub floor). The gas heater is much cheaper to run that the A/C units, so I will be intercepting the heat call from the thermostat and sending that command to the gas ducted. I would also need to prevent the A/C unit indoor fan(s) from running.
As complex as the thermostats are, they're not advanced enough for my "needs" (it's a toy, and I'll mess with it! )

I also want to use logic with some lighting scenes and pool operation. I have a hard automatic cover for the pool. I cannot automate operation of this cover for safety reasons, but I can run the switch through a dry contact in the CBUS circuit to provide status of pool cover position. So when lighting scenes are commanding pool lights to come on for example, if cover = closed, then it won't switch on those lights.

The ability to use logic around the home, will increase the capability of the CBUS enormously, and it will provide facility for good energy savings... I don't care about Co2 emmissions, but I do care about my electricity bills