42 LEDS pulling 2.4 amps?

[BrassMonkey]

noticed on my reefkeeper that my diy 42 led fixture with 4 meanwells and a computer fan are pulling 2.4 - 2.5 amps. doesnt seem right. i believe the reef keeper right because when the heater kicks on (300w) it goes up to 5 amps.

[WingoLED]

noticed on my reefkeeper that my diy 42 led fixture with 4 meanwells and a computer fan are pulling 2.4 - 2.5 amps. doesnt seem right. i believe the reef keeper right because when the heater kicks on (300w) it goes up to 5 amps.


What model drivers and model of LEDs are you using in the light and how do you hook them up(that is how many parallel strings of LEDs?) Also, did you adjust the internal trim?

[bamf25]

This is what I understand as far as how the meanwells work, and I have seen this mentioned before, and I see the same thing on 5 x meanwells eln-48's on my tank. The drivers do not draw a constant current. What they basically do is fill a capacitor in short bursts, and then do not draw from the house current. The LED then run off of that capacitor. When the capacitor starts to run low they will then draw for a brief period to recharge the capacitor. So when you are running multiple meanwells they are not all drawing current at the same time, since they draw in bursts not continuous. Thus the lower amp reading.

[BrassMonkey]

oh ok maybe thats causing the mis reading. its a high reading not a low, lol
42 leds running at .750ma so the leds are consuming 90 watts and the drivers are pulling 275 watts.

[Nick_P]

I am not an EE by any means; however IF he is running his drivers at 750mA wouldn't that be 750mA x 4 (number of drivers) 3000mA (3A)? If he is running XP-Gs at 1300mA white and XP-E 1100mA blue then it would be 4800mA (4.8A).

So his reading would be on the low side?

[Nick_P]

oh ok maybe thats causing the mis reading. its a high reading not a low, lol
42 leds running at .750ma so the leds are consuming 90 watts and the drivers are pulling 275 watts.

Are those calculations correct? Seems like a huge amount of power waste going from 275w to 90w usable. The drivers would surely be overheating.

[nanojg]

I am not an EE by any means; however IF he is running his drivers at 750mA wouldn't that be 750mA x 4 (number of drivers) 3000mA (3A)? If he is running XP-Gs at 1300mA white and XP-E 1100mA blue then it would be 4800mA (4.8A).

So his reading would be on the low side?

No, watts = volts x amps

1 amp from the wall is 110 volts

[Nick_P]

No, watts = volts x amps

1 amp from the wall is 110 volts

I had no idea it worked that way.

[WingoLED]

oh ok maybe thats causing the mis reading. its a high reading not a low, lol
42 leds running at .750ma so the leds are consuming 90 watts and the drivers are pulling 275 watts.

I noticed you said 42 LEDs. It's an odd number for 4 strings, you cannot have 10.5 LEDs per string. So, do you mean 4 x 13 = 52 LEDs?

I do not believe you are running your LEDs at 750ma

You said you had 4 drivers so I assume you connect them in the following manner:
1 driver to 1 string of LED
1 string of LEDs consists of 13 LEDs
Therefore, you have 4 strings of LEDs

Most older Cree LEDs runs at nominal voltage of 3.7v
The Meanwell ELN60-48D default is set to 1.3A. If you(or the seller) have not trimmed the dial inside the driver, you are running your LEDs at 1.3A

Therefore your wattage is 4 string x 13 LEDs x 3.7v x 1.3A = 250W.
Your driver will use for energy in converting 120V ac to the dc for your LEDs and your PC fan, therefore accounting the rest of ~25 watts of energy.

NOTE: This settings are considered OVER DRIVING your LEDs according to Cree unless you are using XP-G or other higher power models.

Please go to Cree website to download the spec sheet for your LEDs and also ask the seller what they set the drivers at. If you cannot get support, email Meanwell USA, the tech support there is very knowledgeable and will be able to answer you but it may take some time before he can reply as there were way too many retailers recently selling their drivers without giving instructions and support to their retail customers. I cannot answer fast enough my local club members/friends about the Meanwell drivers bought online.