C-bus -> RS232 Interface -> Control4 - Power Outage Behaviour

Hi All

I have a nagging issue which has been postponed for a long time now and hope someone can offer some insights.

It is a c-bus network with Dimmers, Relays and Bus Couplers running lights and other circuits and monitoring some critical circuits such as a Backwater station, sump pumps via current transformer/switches etc. A SC5000CTL2-WE black and white touch screen is also connected on C-bus running some PICED programming and logic.

The C-bus network is integrated with a Control4 EA-5 controller via Serial Interface. It is important to have the last active date and time of several circuits available on Control 4 so I took the make shift approach on Control4 Composer of connecting certain C-bus circuits to Control 4 via the "Clipsal Motorization Relay" driver and then connecting the "Generic Pump" driver to these relays since the Generic Pump component shows last active date and time on the Control 4 GUI.

To establish uninterrupted continuity the system is backed up by a Li-Ion battery wall with Victron 48/8000 Inverter/Charger which according to datasheets has a switchover time to battery, in the event of grid outage, of "less than 20milliseconds". The EA-5 controller is further connected to a less expensive line interactive UPS which was installed before the Victron system and left in place for added peace of mind. The system works well, PC and electronic equipment generally show no reaction when grid power is dropped. However, on Control4, directly after a grid outage and switchover to battery all C-bus levels are lost and displayed incorrectly. On some occasions when grid power is dropped this does not happen and all levels are maintained on Control4 but lately they seem to be lost more than maintained. This also applies for C-bus lighting and dimmer levels as shown on the Control 4 app which do not correspond to the actual C-bus states when checked.

So now my question is, over and above all the UPS equipment what else can I do for C-bus levels to be maintained on Control 4 throughout a grid power drop?? Is less than 20ms long enough to cause a C-bus clock miss or something along those lines which causes Control4 to re-initialize the Clipsal C-Bus RS232 driver? Is the problem the EA-5 controller losing power for milliseconds or the C-bus network losing power for milliseconds or both? I am finding it hard to figure out what happens in these milliseconds which causes the issue.

As a side note I should also mention that it seems Control 4 re-initializes the RS232 driver periodically (once a month or so) which also causes all C-bus levels to be lost on Control 4. I haven't been able to find a workaround for this either.

 

What version of Composer Pro? are you on the most recent clipsal drivers? are you saying it happens with lighting as well as the motorisation devices?
I use control4 and c-bus regularly and haven't noticed this before (might be happening but I haven't picked up on it.
Are you using the PCI for periodic toolkit programming as well as for the control4 system if so you will need to press the re-initialise button in the properties tab of the driver after you have finished using the PCI for toolkit.

I would expect control4 polls all the c-bus group addresses after a powercut to determine if anything has changed since it was offline but I haven't looked in the lua output straight after a power outage.

Good luck and let us know what you find.

 

PS: I hear there are new clipsal cbus drivers in creation for c4 and due for release once fully tested.

 

Hi DGF, thanks for sharing your thoughts. I have another USB PCI which I use for periodic Toolkit programming, although not often. The PCI for C4 is a dedicated serial PCI.

I did some further investigation and noticed that even the incidents which I thought did not coincide with a power outage actually did coincide with momentary power outages/dips of less than a minute and typically a couple of seconds. Perhaps switching or momentary load fluctuations on the utility providers network, not sure. I picked this up in the Victron Quattro Inverter's logs showing rare short periods of no AC-In with inverting active. Without these logs I never would have been aware of this. So it seems every C4 loss of C-bus states coincides with a power dip even if only momentarily and is not related to some type of C4 driver periodic re-initialization as the installer initially led me to believe.

This makes me think the line-interactive UPS which does not give true uninterrupted supply coupled with the Inverter's <20ms switchover time is indeed enough to trigger a communication glitch on the C4 controller or C-bus network. Hopefully just the C4 controller because what I am currently busy with is to replace the line-interactive UPS with an online double conversion true sine wave UPS (Eaton 2E9000i). Only the C4 controller will be covered though, putting all the C-bus units behind a UPS will be a big wiring exercise.

This way when the Quattro Inverter does its 20ms switch to battery during a power outage the C4 controller will never lose power, not even for a moment due to the online double conversion topology. The annoying thing however is that the inverter switchover causes an Earth Leakage trip when grid power is restored with the new UPS downstream so I had to source an Auto Reset RCCD. It is a separate issue beyond the scope of this thread but it basically boils down to the Inverter's sequence of operation when AC power is restored. It opens its N-E bonding relay a moment before making incoming AC and making the upstream utility providers N-E bond visible again. This moment with no N-E bond caused the Eaton UPS to behave in a way which triggers the RCCD. Not entirely sure what happens internally on the Eaton UPS when this occurs but it obviously causes a momentary earth leak. The line-interactive UPS did not have this problem.

I am hoping with this setup C4 will maintain C-bus states at all times but time will tell.