Power Management/UPS/Generator

Here in South Africa we're going through a torrid time of load shedding. We will have rolling power cuts across the country for the next few years on a daily basis. I'd like to leverage some of my C-Bus smarts to better manage the power at home using the following scenario, and I'd appreciate comments.

1. Put C-Bus power on to UPS - I have to keep the logic up and running in a power failure
2. Wire UPS serial interface into PAC - I need to know when I've lost power right?
3. Replace the circuit-breaker for my big consumers with CT contact circuit-breakers - this will allow me to use a relay channel to switch the breaker on and off
4. In a power failure, C-Bus switches off big consumers (pool pump, undefloor heating, geysers, etc)
5. Then a C-bus relay auto-starts my generator

Presumably it inadvisable to use relay channels to switch big loads such as HVAC and pool pump directly? It would also mean re-wiring a little as these circuits are currently wired through the main distribution board on their own breakers.

Following the above approach I don't need a gen-set that supports the full power consumption of the house.

I'd appreciate any input on the idea.

 

Just a comment on one of the things you've said:
You don't need to run loads heavier than 10A directly off C-Bus relays, there are relay drivers designed for this purpose.
Have a look at:
http://www2.clipsal.com/cis/technical/product_groups/cbus/output_units/relay_units
for all of the available C-Bus relays.
Using some of the relay drivers, you could run contactors to control the heavier loads (>20A), and for loads between 10 and 20 Amps, use the 20A Latching Relay.

Darpa

 

Also, it might be easier not to wire a serial connection between the UPS and PAC.
If all you want to know is that you've lost power, I'd just run a small plug-pack transformer, or any other power supply that you have that gives you less than 20V DC, into a General Input Unit (5504GI). Simply have a GPO (Power Point) installed so that it draws it's power from the main's feed, install it BEFORE the contactors that connect/disconnect the gen-set/mains feeds, on the mains feeds side, and this way you would also be able to tell when mains power had been restored, and program C-Bus to act accordingly (Ie; switch back to mains power, shut down the gen-set, and re-enable the high-amp loads in your house).
The high-level integration that would be required between the UPS and PAC would most likely be more hassle than it was worth.
It would however be able to tell C-Bus how long the power coming from the UPS's batteries was going to last, but that would be the only real benefit.

Darpa

P.S. Your post makes me realise how lucky the rest of us are to have a reliable power grid