CBUS PROBLEM - lights lock on with switch

We have an on going CBUS problem that I am now VERY concerned about.

The system consists of 2 off 5A dimmers 1 off 2A dimmer 1 off 12 ch relay - a number of E200 switches - a number of saturn 2 and 4 button - 3 off DLT.

There was a comfort connected and a B&W touch screen now both physically removed.

Installation is now 2years plus old - problems started 6 month or so after comissioning and have got progressively worse.

At intermitent times (although it appears to happen more in the evenings) when certain light switches are pressed the lighting locks ON. The only way to re-activate is by switching all off at the breaker and then back on.


We have been to site on several occasions now and tried a multitude of different things, one of the few options left is to change the transformers on the down lights - which i'm told have too great a capacitive value.

Anybody had experience of this problem or indeed the symptoms of incorrect capacitive values in the circuit.

 

One thing to check

If everything goes on at once, it may be an accidental triggering of the Remote On function. If there are any wires remaining from the touch or the comfort they could be picking up some interference and sending enough voltage down the Green wire to trigger this function. If you suspect this, I would disconnect all but the CBUS + and - from my output units to prevent it from happening.

 

Can you provide some more information?

1) what exactly do you mean by "locks ON"...
- does it go to full brightness even if you just dim it up a little?
- does it turn on and then just stop responding?
turns on to full brightness and then stops responding altogether

2) Is it always the same channel that stops responding?
- is it one channel, one dimmer, or all devices on the network?
It is certainly both of the 5A dimmers and all channels not just the channel that may have been switched.

3) You say "certain light switches"
- does this mean it only happens from a particular switch (ie controlling the same channel from a different switch is OK), or do you mean that it's always the same channel(s)? it happens from a variety of different light switches BUT i expect that they all switch circuits associated with the 5A dimmers

4) If it's the channel(s) not responding to the switches.... when you press the switch, do the indicators behave normally (ie toggle on/off as you try to turn the load on/off), or do they flash quickly (flashing quickly indicates that the switch was unable to communicate on the bus). Not sure of this one ill put it to the customer! My guess is that the indicators come on and stay on

Was anything added to the house (extra work/services/wiring) around the time that things started misbehaving? It's not uncommon with seemingly erratic behaviour like this to find some other tradesman or even the owner has come along later and put a drill/screw/nail through the cable somewhere.

Not that i am aware of.


Nick

 

Had already thought of this and acted.

We are about to change the transformers in the downlights - I was wanting to know the symptoms of incorrect capacitance values on the loads.