LED help!!

[rodster912000]

i recently setup a diy led suppliment strip to go with my halides. its controled by my reefkeeper elite but i seem to be having a problem and im hoping someone can help. here is what i have...
2 Mean Well ELN-60-48D dimmable driver
2 1.1" x 48" Aluminum Heatsink
16 CREE XP-E Royal Blue 3W LED with 55 degree Black Lens
8 CREE XP-G R5 Cool White 3W LED with 65 degree Black Lens
Checking my graphs from the reefkeeper the lights seem to be ramping up and down properly. now each driver is runing 12 leds but recently one led burned out so one is runing 11, by specs they run 8-14 so i would think its ok. my problem starts when one of the drivers initialy turns on my ph drops from 7-8 to 3-4. this only happens when one specific drive turns on and off. by looking at the graph its clear that this driver is directly effecting the ph probe.(temp probe is not effected)
Also with my alc unit when the drivers turn on and begin to ramp-up the leds just glow until they hit 10(on the alc) then they click on like a light switch and begin to ramp up in intensity from that point.....is this normal?? i would think they should ramp from 1-whatever i set them to run at. any help would be greatly apreciated.

 

[der_wille_zur_macht]

Meanwell drivers have a "shoulder" low down in their dimming curve, such that they behave like you are describing. You get nothing until about 10 percent and then a jump up to about 15 percent, though the exact values depend on which version of the driver you have.

Regarding the pH problem - you're seeing interference because the pH module you're using is not (well or at all) isolated. You could try working with the controller manufacturer on this but I wouldn't expect much since it's a typical "blame the other guy" thing between the two vendors. There may be simple things you can try (rerouting wiring, switching where things are plugged in, etc) that might help though.

Also, make SURE that LED is actually burned out and not bypassed via multiple shorts to the heatsink, or you may be sitting on a dangerous situation. If you have a multimeter, put it on continuity mode and check for continuity between the wiring and the heatsink.

 

[der_wille_zur_macht]

Also, how many of each LED are on each driver and what current are they running at?

 

[rodster912000]

thank you for the fast reply. i have attempted to try and move things arround...ph probe to the other side of the sump along with the alc modul and sl1 with no change. i currently have the drivers on one side of the stand and the moduls/probes on the other and the problem is still there. i actualy removed that led when it stoped working, checked it with the tester supplyed from rapidled and it didnt work. but i think you are right in saying that there was a short becouse i notice a bit of a zap when touching the water and the aluminum stand i have the lights hanging from. This was corrected when that led was removed. i am thinking that the led died on me becouse of a short between him and the heatsink.
Do you think that the meanwell wiring can also be creating interference or is it just the driver it self. i wonder if there are any home remedys for electronic interference, such as wrapping with aluminum foil or somthing silly like that.

 

[rodster912000]

i made two 48 in strips with 12 royal b running off one driver and 8 cool white/4 royal b running off the other driver. both drivers i set to run max just under 1000ma. royal blue max at 1000 and cool white max 1500. the led that burned out was a cool white. so im thinking it had to be like what you said with shorts to the heatsink that caused it.

 

[rodster912000]

just ordered replacement led's and spares. also 80 degree lense, due to a small amount of spot lighting.

 

[der_wille_zur_macht]

If I were you I would unplug everything and check for shorts or other wiring problems. If you're getting zapped then there's a problem. You can also try swapping the two drivers to see if the problem "stays" with the array or the driver.

Assuming there isn't an obvious fault in the array or driver or wiring you can move on - shielding will likely not fix this since the issue is probably not directly caused by rf but the LED driver inducing a voltage in the water that the probe is picking up directly from the water. The amp the probe is attached to (inside your controller) is probably not well isolated, but you can't solve that without ripping your controller apart and redesigning from scratch. If it was well isolated this sort of induced voltage wouldn't be causing you this sort of issue.

Do you have the LED drivers running on a power strip controlled by the controller or plugged directly into the wall? If they're in a controlled strip I would try swapping to other positions and/or plugging directly into a wall receptacle.

 

[rodster912000]

they are turned on and off by the controler otherwise the leds will glow 24/7 unlees i put them on a time if i were to plug them directly into the wall.i am in the processnow of performing the cont. test and if i find nothing there i plan to switch the driver like you said and if i still find nothing i will try pluging them directly into an outlet with a timer. thank you for all your help i fear if i dont find out the issue soon it could be catastrofic