Plc controlled dimmer, led lightbulb flickering

[blackbird307]

I'm stumped. We have a 8 ch 600W dimmer than controls 8 led lightbulb circuits. When the dimmer receives a control voltage of 0-10, the lights should be 0% or 100%. When approaching 0 at about 10%. The leds lightbulbs flash on, then off really fast.

Remove one light bulb and replace it with an incandescent bulb they all stop flashing. But at 0% the leds are still on, the incandescent is not. So it's very noticeable. At 0% there is a 20v peak to peak sine wave at the outputs of the channel which would explain why the leds are still on. Anyone have a solution besides just throwing an incandescent lightbulb in. Im stumped!

The led lightbulbs are 6.5w each, the incandescent is 60w.

 

[tarik1978]

Check these links:
https://www.cnet.com/how-to/how-to-buy-dimmable-led-bulbs-that-wont-hum-flicker-or-buzz/
http://luxreview.com/article/2016/02/10-things-you-must-know-before-you-dim-led-lamps

 

[Boorabee Parker]

I'm stumped. We have a 8 ch 600W dimmer than controls 8 led lightbulb circuits. When the dimmer receives a control voltage of 0-10, the lights should be 0% or 100%. When approaching 0 at about 10%. The leds lightbulbs flash on, then off really fast.

Remove one light bulb and replace it with an incandescent bulb they all stop flashing. But at 0% the leds are still on, the incandescent is not. So it's very noticeable. At 0% there is a 20v peak to peak sine wave at the outputs of the channel which would explain why the leds are still on. Anyone have a solution besides just throwing an incandescent lightbulb in. Im stumped!

The led lightbulbs are 6.5w each, the incandescent is 60w.

There is not enough load on the dimmer when at 10% or less, hence why when you put a incandescent bulb (60w) this loads up the dimmer enough to operate as it should. It is a common problem. A dummy load needs to be connected to the dimmer. Clipsal Schneider make such a device, but for domestic use not commercial applications

 

[daba]

I had exactly this problem - I changed (over time) all my household incandescent bulbs to LED. Power saving and longer life were the impetus.

In my lounge I had a 3-lamp fitment, controlled by a standard dimmer. It had 3 x 40W incandescent bulbs in. When I changed the lamps to dimmable LED equivalents, they would flicker at low-light levels. Changing the dimmer module to one that was rated and designed for LED bulbs has completely solved the problem.

Your 8-channel dimmer controller obviously isn't designed for the lower-current LED loads. You have several options, all of which assume you want to retain the LED lighting....

1. Replace the 8-channel dimmer controller to one that can correctly dim LED lamps, assuming such a device exists.

2. Replace the 8-channel dimmer controller with 8 independent dimmer modules that are rated for LED, AND have a 0-10V control input, assuming such devices exist.

3. Add dummy loads, to satisfy the minimum load requirements of the existing 8-channel module. This will definitely use devices that exist - you already have them.

Of course no.3 will be the least expensive to implement, but the most expensive to run in the long-term, since you have to dissipate that extra power somewhere, either bulbs or load-bank resistors.

Be aware that only about 3 to 5% of the power you put into a bulb comes off as light, the rest is heat, so be careful where you put your parasitic loads - a cabinet full of bulbs could get very nearly as hot as a cabinet full of load resistors. Your cabinet may require forced cooling.

You have to make choices, hopefully they will be kind to your carbon footprint...