A whole C-Bus Relaying turning on itself every single night

Hi

My whole house is controlled by C-Bus, lightning, blinds.

As of a couple a week ago one relay is switching on every night at least once but up to 3 times.

Every light and blind on that relay turns on. I then have to manually go down to the board and switch off every single node. ie it then goes into override mode.

Do you know what could possible causing this to happen? Thank you

 

Likely the remote on function triggering. This is two of the four pairs in the cat5 cable used for remote on/off. If no other units are being triggered then I would guess that this relay unit has an internal fault. The remote on state can be seen in the unit detail in Toolkit to verify.

This happened to one of my four channel relays, but it would only turn all on about once a month. Thankfully I was able to identify some kind of sticky pad that was lying across some board traces, visible by shining a torch once the relay had been removed from the board. I was able to get the pad out by 'tweezering' it with some bamboo skewers. The fault disappeared. I've no idea how it got in there, maybe at time of manufacture.

That relay was installed in a shed that tended to get quite hot over summer, so maybe that messed with the adhesive.

 

This is happening with me also! Was just one dimmer unit once every six months, but this morning it was the relay which has a lot more channels and controls the towel rails, so the bathrooms were like sauna’s!
Are there any other ways to disable this from being possible in the hardware somehow?
Wonder if it would be worthwhile writing a script so that once an hour it checks if every channel is on on each relay/dimmer, or is it possible to check this “remote on” state mentioned?
Really want to get this sorted ASAP as scared to even go on holiday currently, especially as the phone app is incredibly unreliable at reporting the correct state of channels (and probably would it even report them as on if they were switched on via a short circuit instead of a button press?)

 

The remote on and off function is a holdover from early systems that did not support scenes (was also use in some commercial applications). It's completely unnecessary in domestic installs and just a cause of problems. Unfortunately many installers keep connection it through and I have even seen them bought back to 2 buttons which is crazy. You don't have much choice with the RJ45 connectors, but I never connect it through at switches or other 2 terminal devices. You can just break the green and brown pairs where it enters the switchboard or any other convenient point.

Unfortunately there is no programatical way of disabling the remote on/off functions, nor testing it's state. It only needs a brief and tiny current to trigger it anyway, so the best solution is to just disconnect the pairs.

 

Have you checked that there is no group address programmed into the area address of that relay.

 

Appreciate the info @Ashley ! My units are all star wired back to a patch panel, what would be the best thing to do in this case to disconnect those two wires without breaking anything?! I can try to get a photo of the back of the patch panel but assume you’ve probably seen this type of arrangement before?

 

If I have “relayb” and “dimmera” being referenced when I hit the “all off” scene which turns off every channel on that unit, would that be a yes to your question?

 

if you have “relayb” and “dimmera” which are Group tag names in a scene and in the area address location and somehow that GA gets turned on then yes this may be the reason

Leave toolkit open and running to allow the application log to see if a GA is turning on at the time when the problem occurs.

Any group address in the Area section will turn on or off all channels of that particular unit