Dimmer not responding

HI
I having some problems with 3 x 8 channel dimmers that are daisy chained together on the end of a CBus network run. The unit LEDs on all three dimmers are blinking and none of the output LEDs are lit. If I remove the cat5 from the CBus connection on the unit farthest from the end of the run then the CBus LED extinguishes (no Network) and the ouput LEDs Light up on a number of channels.
Now if I partially insert the cat5 back into the connector on the dimmer everything functions normally but if I push it a bit further until the clip on the plug locks into place then the problem re-appears and all output LEDs extinguish and the unit LEDs again blink.
I have isolated this dimmer from the other two and still have the problem.
I've swapped the cat5 which comes out of a 2000 series wall plate with comms sockets into the dimmer for a different cable without any change.
There are 21 units in all on the network and all other relays,dimmers and switches appear to be functioning normally.


Thanks
Chris

 

Is the blinking of the Unit LED a brief blink off followed by a sustained on period? If so, and the channel LEDs go out, then it suggests that the remote override off is active.

Is the C-Bus LED on or off when you plug in the cable?

 

Hi Newman

I think from memory that is what it is doing. I've just had a play with a different dimmer sitting on my desk and the on period, I'm seeing from memory with the problem units does appears to be longer than the blink that I am seeing here on the desk unit when a channel LED was pressed.

The C-Bus LED is on both with the cable half plugged in and fully plugged in. Off when cable un-plugged.

 

It may happen when one of the cable is wrongly terminated inside the RJ45. if someone grab a network cable, cut one side of it, and just use the orange/blue pairs on some joining point, the remote off may happen. I forgot if it happened with a straight or cross cable....but it happened before.

 

I agree with Wanricky, it's most likely an incorrectly terminated RJ45 somewhere.

 

seems to me the remote override OFF connection in the C-Bus cable is active. While either local toggle OR remote override is active, a C-Bus output unit will "blink" the unit LED

 

Thanks for your responses.

I'll rewire the RJ45's (there are six of them on the plate) as they are wired loop in loop out. There are 2 8 gang neo's a remote relay (about 6 meters away) and the incoming C-Bus network from the rest of the installation all terminated in these sockets. RJ45 wiring is pretty agricultural.

 

normally it is just one cable with one open end and one RJ45 end. People who terminate a lot of normal lan cable would have done that. Fortunately it is only remote off, not on or short circuit, and when you see it once or twice, you will remember not to do that same in the rest of your jobs....