Unusual dimmer behaviour

Hey everyone.

Having some issues with a new C-Bus install at the moment whereby dimmed circuits that are ON will turn OFF for a couple of secs and then ON again upon the client pushing a C-Bus switch or if detected by a motion sensor in the pantry. It's definitely not a programming issue as the fault is intermittant and can't be replicated. It doesn't appear to be affecting relay switched circuits.

I have been suspecting a possible mains supply issue? Overvoltage maybe? When the intermittant fault occurs all CBUS units appear ok, no flashing of lights on switches or output hardware occur. The house then returns to normal operation. This one has me beat.

Have used the Universal Dimmers on other installs and never seen an install with this problem before. Any ideas.

Thanks,
Deano

 

Hi

I've had a problem like this which was low mains voltage on one phase impacting the one relay unit on that phase.

in my case the C-bus status lights on the relay went off i.e all LEDs on the C-bus relay go off including the C-bus network LEDS. The phase was dropping to 190v

Cheers
Michael

 

I'm having exactly the same issue with 2 channels on a universal dimmer. Each channel has only 5x 50w halogen globes using clipsal hunter electronic transformers???

 

Hey,

I have seen this on one job. It was due to electronic transformers and the induction of the in rush into other cables I believe. The Universal dimmer then gets confused about what load is on it and turns off, or something like that. I am sure one of the experts might be able to help with a more technical explanation.

Anyway we were put on to the Inductor Filter Modules and it appears to have worked a treat. Clipsal Product Link Might be worth a try?

 

The high inrush current present with some electronic loads (and cheap LED lamps are the worst) causes such a large current spike that it can cause the short-circuit protection in the dimmer to activate. The dimmer needs to shut the channel down at some point to protect itself and it seems that some of these cheap lamps can have inrush currents large enough to trip the protection circuitry. The dimmer channel re-starts itself after a second or two. After a couple of tries it gives up, requiring you to turn the channel off and then on again.

If the magnitude of the current spike isn't too large then you can usually knock it down a fair bit by using a 32EIND. It's definitely worth a shot.