We have 2 Crestron DIN-1DIMU4 and are doing LED dimming loads. It is
not working reliablly, turns on, but then goes off right away, will
not dim most of the time, when it does it "stutters" and goes off.

Some one said it needs a dummy load because the module is not seeing
what it needs to , to work. we put a 60 watt incandeccant along with
one of the dimmanle LED loads and it worked fine.

Anyone know of a good dummy load (not the Lutron double gang option)
Someone said a 10k ohm 10 watt resistor..... a Crestron tech guy said
it may be done in programming in D3 .... Help

Scoop

Lutron LBX?

I've also used a resistor, I'll have to dig around to find out where I bought it.

I don't do Crestron, but I don't see how any amount of programming could show a dummy load on a dimming module.

What type of LED light is it? How much does current does it draw? We use the Lutron LUT LBX often with great success. You can place it anywhere between your dimmer and the load.
Zinon

As with many things, there can be firmware activated to either deal with the load in place a resistor in the circuit. Lutron does this with their phase lock loop circuit for example, different application but still an example of how software can be used to deal with a physical issue.

I have not looked into D3 to see where this setting might be--assuming it exists. If you have to go the route of an external resistor keep in mind it will get really hot and need to be heat sinked.

Alan

I would check the programming option or the Lutron option. Adding a resistor does work but can leave you exposed to liability if not done correctly pertaining to heat sink.

How do you have the Load type defined in D3? They do have LV options within the load type as your LED's don't pull a lot.

Just a suggestion, not sure if it would work on not, haven't had to deal with that yet.

Instead of a resistor, use a light bulb at the panel until there are mods made to the dimmer module to support your LED. You most likely only need a 25w bulb.
Which LED product are you using? Total wattage on that leg of the dimmer?

Try changing the lower dimming limit to 3% or 5% on that load, that should clear up the flickering. There is a document on Crestron's website that indicates what levels for different brands.

Here is one of the TOTL power resistors. We use this series a lot in power control.
[Link: vishay.com]

If you do the calcs, you'll find that 10K throws off only 1.44 watts of heat when it sees a full 120 VAC RMS. This does not seem to be much power at all.

Don't let that make you think it won't get plenty hot, though. We're really not familiar with how much heat that can be, especially if it's in a confined space. I've burned my finger on a 1/2 watt resistor that's got 1/4 watt of power going through it. You will definitely need to provide heat sinking for that resistor and the system will have to be comfortable with a small hot spot in it.

the electrician is using 601-12DCR and C2240-12DCR dimming power supplies
by Environmental Lights (actual manufacturer is Justin)

this is what we are trying to get Crestron DIN-1DIM4U to control.

Just be careful, sometimes your Dimmable LEDs do not work by lowering the Voltage, but by managing the amperage. do they work with regular standalone dimmers?

Also, the dimming range might not be 0 - 100, the lowest possible input voltage of the power supply could be 80V for a minimum brightness. So you could program that dimmer to its relative zero to be about 60% ...

To be honest I had some bad experience with dimming Leds, if I was the one to choose the fixtures i could get some compatible with the dimmers... but most of the times it's either the customer or the designers that chooses the lights, so I just get them a switch. =P

Litetouch sells a 25w load resistor, but it's just a generic part. They only sell it so their dealers can easily find it. I'm dealing with dimmable LEDs today as well and having the exact same problem you're describing... may be ordering a handful of them.

Ernie's calculation of the power dissipation is correct.

An important concept to remember is that resistor power ratings are based on a temperature rise above 25C. (Room temp for those who don't speak SI units) So if you don't want a resistor to get very hot, buy a resistor rated for about 5x the power you intend to dissipate.

So, in this case you would need to select a resistor that is capable of 1.44W x 5 = 7.2W The next highest standard wattage is 10Watts, so I would use a 10K ohm 10 Watt resistor.

The following would be a good choice: [Link: search.digikey.com]

You would need to solder two leads to the terminals, and then insulate the connections with electrical tape or heat shrink tubing. I would then suggest mounting it in a metal junction box using the two "ears" on the anodized aluminum body to mount it using a couple self tapping screws.

Here it is. No hacking needed.





Litetouch sells it with leads soldered onto it for you.