Is best solution to get rid of Dimmers?

Hi, thanks in advance for any help people can offer.

I am an unfortunate CBUS slave, and have had electricians try and solve an issue of lights randomly shutting off on one 8 Channel dimmer module.

I get a usual spiel about new LED lights not being compatible with the C-Bus Dimmer modules but when they replace an old module they always replace it with a new Dimmer module. The crazy thing is that I never dim my lights at all so I don't need the dimming function.

Am I crazy in thinking that the best solution to getting a CBus system to work with modern LED lights is just to replace old Dimmers with normal relays? Will this fix the issue of their not being enough load on the circuit to make it work properly - as a relay is a simple on/off?

I have a number of Dimmers reaching around 15 years of age and as they fail I want to just replace them with relays so they just work like a normal light - on and off.

Can anyone fill me in on why the solutions being offerred to me are not to replace my dimmers with relays but:
1. Go back to using halogens as the system was designed for; or
2. Do rigorous testing to see if the dimmable LED works with the CBus dimmers.

Thanks again.

 

Leds will not cause lights to randomly shut off on a dimmer. They may flash, dim poorly, not turn on at all, or not turn off completely, but this will be a consistent behaviour.

You need to get a experience cbus provider to diagnose this problem. It could be an intermittent power supply to the dimmer (even a poorly made connection can do it), a fault with the Cbus cabling, or some errant logic or schedules or even scenes actually turning off the lights. These problems can be easily diagnosed by the right person with the right equipment.

As for replacing the dimmers with relays, all leds work fine on relays. This will only work of course if the leds are the problem. Have to tried changing all the leds back to incandescents and see if the problem persists?

 

Thanks Ashley for your reply.

The reason for my post is that I just want to be clear in my mind what the way forward is. My electrician is experienced with C-Bus but there are several ways forward and each will be relatively expensive. I want to go with the one that guarantees that the system will work well with new LED lighting, as I have already purchased LEDs and the manufacture of halogen seems to be disappearing. I don't care if they dim or not.

My system has 4 15 yr old Dimmers (1x 8 Ch and 3 4Ch) and 2 15 yr old 12 Ch relays. I also have 2 new 8Ch Dimmers installed, So I'm trying to create a replacement plan that makes the system as stable as possible.

I believe actual problem is simply that this Dimmer module is old and needs replacing. The question in my mind is whether I keep going down the road of replacing dimmers with dimmers, given the lack of true compatibility with LEDs, or whether I bite the bullet and change the dimmers to relays.

Do the problems you mention with dimmers "They may flash, dim poorly, not turn on at all, or not turn off completely" also happen with relays or are relays more reliable? If they reliably switch LEDs lights on and off, with no issues regarding sufficient load on the circuit etc, I think that may be the way to go.

Thanks again.

 

Regarding this question. I haven't yet. This was the next step, but I disposed of all my old halogens and the only ones I have left are in hard to reach locations and some of the transformers have already gone, so I'm just trying to work out if I go to that trouble or if I replace the 15 year old Dimmer module that is playing up.

So, if the conclusion is that "all LEDs work fine with relays". Then I think that may help confirm the direction I want to head in.

 

Yes, all leds work fine with relays.

However, if you don't want to dim, then dimmers will work fine as relays given sufficient load.

There are 2 issues here:
1/ If you don't have sufficient load, the leds won't turn on. This can be a function of the transformer (only solid state ones) that need a minimum load to operate. Transformers designed for leds don't have this problem.
2/ If you don't have sufficient load, the leds may glow slightly when turned off due to residual current in the dimmer outputs. This can usually be solved by 31LCDA load correction device.

Just set the switches up as on/off and not dimmers.

I would try this first as it's a much cheaper option.

Many people have led lighting working on Cbus dimmers. It's a horrible solutions using phase control to dim leds but we seem to be stuck with it at the present time.

I guess dimming is a personal thing, but I wouldn't be without it.

 

Thanks Ashley for your help.

I'm going through all the channels now as I have two relatively new dimmer modules so I'll work out which rooms we could keep dimmers in if we need to show off the system's capabilities, and convert the rest to relays.

 

There was a time when Clipsal training recommended using a relay inline with a dimmer channel to remove flicking etc from LEDs.

I’ve come across various external LED driver modules that even between batches behave differently on CBUS dimmers. I eventually narrowed it down to a few drivers that I use with clients that don’t or only extremely rarely flick on a single LED.