Channels not using the dimming curve

[schenery]

Hi All

New to LOR this year and have just finished setting up my controller and hooking it up to LED light strings. All channels have been set to use the dimming curve 1 that comes as a default and this works fine on channels 1,2,3,4,7,8,9 and 10. On channel 5,6,11,12,13,14,15,16 it looks like it is using the lor standard curve.

If I change the dimming curve to be on/off for all the channels, they perform using this method and at 50% they turn on. So the channels in question are reading the curve ok

When all channels set to the dimming curve 1 the ones that don't work as expected just turn on full straight away where the other channels will become brighter over the increase in intensity.

All led strings are the same, same number of LEDs, same length.

I am also using the latest software via a USB interface brought through lor.

Does anyone have any idea as to where I should be lookingto fix this?

Thanks

Steven

[schenery]

I have done some more testing on this and it seems to be the length of the extension cable to the lights that affects the ability to have the dimming function work correctly. It seems that around 15 meters in length it fails to dim. Is this right? is this what others are seeing?

[-klb-]

1) are you using grounded extension cords? If so, try switching to ungrounded cords.

2) Since you have dimming curves, it sounds like you already have a 3rd Gen controller with phantom load. But try more phantom load. Just to prove it is the issue, start with a string of mini lights plugged in with the LED lights. Ignore how the mini lights dim, just focus on the LED.

[schenery]

klb, Thanks for your thoughts.

Yes all extension cords are grounded. I have searched high and low for an extension cord that is not grounded and have not found one. So I will keep looking for one so this can be tested.

Yes i have a 3rd Gen controller and will increase the load to see if that changes the outcome. I’ll let you know shortly.

Background to the actual setup:
I have 6 identical tress with Red, Blue and Green LED's sitting on top of the brick fence pylons. The Blue and green are connected to a channel (6 trees x 2 colours =12 channels) and the red is connected to channel 13. Green is on channel 1,2,3,4,5,6.(Matches tree number) Red is on 7,8,9,10,11,12. Red is on channel 13 and on for all trees.
Each tree (3 feet, 90 cm) has 220 LED's per channel for 1 colour. (660 LED’s per tress, 3 colours) As the Red is on one channel there are 1320 LED’s on channel 13.

Tree 1. Tree 2 (Controller sits with tree 2), Tree 3 and Tree 4 all work for Blue and Green.

Tree 5, 6 and Channel 13 (Red LEDs) with longer extension cables are the ones that have the issue with the dimming.

Channel 14,15 and 16 are on the roof and are also affected but are not as noticeable as they are not in a group and are independent.

[schenery]

Ok, so what it looks like is the extension cable length is the culprit. Placing an additional load on the channel via a phantom/ghost load gets the channel to dim correctly. Still don't understand this concept just yet but now have something to work with...

Thanks

[-klb-]

All light strings and extension cords act as capacitors. Grounded cords do it more than ungrounded ones. With incandescent lights, it does not matter, as they draw the voltage back down to zero. But LED strings will only draw the voltage back down to between 60 and 90 volts. This causes issues. You either need enough phantom load for the capacitance at hand, or reduce the capacitance to what the phantom load can drain.