480W LED light not hitting 480W

Hey all, I bought a LEd light from Kingbrite
Pre-wired hl-g550 v2 KB-QB288x4 lm301b with epistar 660nm red kingbrite led grow light
Lamp Power(W):480,Emitting Color:3500k+epistar 660nm

I ran a power test using a Watt meter. When I had the knob on the light to max, the max wattage was 464. This light is new. Should it be hitting 480W? Should I be concerned? Or is this normal?

It is what it is, how accurate is the watt meter?

Sometimes the dimmer potentiometer isn't exactly "full value" for example a 100k pot that only tests at 99k ohms when maxed out. this can cause the dimmer knob to not achieve full brightness. The fix is to add a resistor in series with the potentiometer to achieve full value (whatever thats supposed to be). So if you suspect this to be the case (check the driver numbers) then just measure the pot's resistance and see if it's getting where it should be.

BTW I am not familiar with that particular light so I could be off target but if it has a common meanwell driver then it could just be a potentiometer issue. You could simply disconnect the pot (one wire) and leave the circuit open (on a meanwell driver at least) then the light should run at full power.

Renfro said:

BTW I am not familiar with that particular light so I could be off target but if it has a common meanwell driver then it could just be a potentiometer issue. You could simply disconnect the pot (one wire) and leave the circuit open (on a meanwell driver at least) then the light should run at full power.

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I will try that thanks! Im not sure how accurate the meter is. I have a second watt meter coming so I will check with that one

peterk426 said:

Hey all, I bought a LEd light from Kingbrite
Pre-wired hl-g550 v2 KB-QB288x4 lm301b with epistar 660nm red kingbrite led grow light
Lamp Power(W):480,Emitting Color:3500k+epistar 660nm

I ran a power test using a Watt meter. When I had the knob on the light to max, the max wattage was 464. This light is new. Should it be hitting 480W? Should I be concerned? Or is this normal?

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I have a slightly lower than 600 watt draw from my HLG 600, appears there is sometimes a few watts difference. In the end I don't think the 16 watts will make much difference to you so I would try not to worry about it too much. I can't add to what Renfro said, he knows much more about electrical than I. I would suggest just trying your new meter and if it's still down by only 16 watts than ignore it but that is up to you. How are you liking the light?

Generally lights will draw more than they put out. If they’re quality @peterk426 leds with Epistar diodes are generally junk.

Operating temperature does affect the current draw.

Wanderer1 said:

Operating temperature does affect the current draw.

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This is true but we aren't talking about drawing more current, rather less current. Even if it's 100% efficient (impossible) the driver should pull at least 480 watts if it's a 480 watt light. That said, ratings probably come with a plus/minus factor and so does the meter being used to quantify the real world wattage.

If I set, using a Kilowatt and a MW 600 54A for example, to a draw at the plug of 400 watts room temp of 80f. When I turn a fan on and temp drops to 78 it will reduce the wattage draw to the 360-370 range. When the ambient temp is close to 90f it will pull over 700 watts at the plug. Just an observation that may help explain. Have a good one.

Wanderer1 said:

If I set, using a Kilowatt and a MW 600 54A for example, to a draw at the plug of 400 watts room temp of 80f. When I turn a fan on and temp drops to 78 it will reduce the wattage draw to the 360-370 range. When the ambient temp is close to 90f it will pull over 700 watts at the plug. Just an observation that may help explain. Have a good one.

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Is the fan blowing just on the driver or is it also cooling the LED heatsink as well? Interesting observation.

This particular setup has the driver remote mounted and separate, HLG 600H R Spec light in a 5x7 area of a small room. I noticed this relationship of temp to power draw when setting height by par one day in a tent. I had set at 400 watts from the wall, warmed up for an hour, hung at 26" for around 850 par. Checked it a few hours later and noticed the current draw had risen almost 50 watts as the canopy temp had risen about 4 degrees. I have conclude that the MW drivers I have show much more variation in temp/wattage than the Inventronics EUD 600 driver I have. If the the watts change then your PAR changes when using QB's and when the changes or their is added airflow over the heatsink, I encounter up to 10% wattage draw variations. Try it out and verify with other setups, this has been and continues to be my experience. Have a good one, TC. Edit: looking at a setup right now. Canopy temp is 79.7 with 51%, driver temp is 93, slate is 105 and pulling 389 watts. An hour ago a fan had been running in the room giving a canopy temp of about 77 while pulling 367 watts. At 82 it will draw about 410.

Lights will usually state a wattage like 480 +- 5%( the percentage might be different)
This means it wil put out 480 watts give or take 5%
5% of 480 is 24 , so in this case the light could put out anywhere from 456 watts to 504 watts.
Hope this helps.