Quick question, samsung f gen strip

From my understanding the softer you run the leds the higher the lumen per watt. When looking at the datasheet, the 4 ft 3000k at 46v ,1.12a gives 168l/w, but at 43.7 v at 1.12amp the lumen per watt goes down to 151lm/w. What am i not getting?

datasheet just shows you the range in which the leds have been tested in. min/max/average

I think i get that. But they list lower lumens per watt when running softer, for example lower voltage, lower wattage. So yes total lumens with lower voltage n wattage would go down, but shouldnt the lumens per watt go up?

Warpedpassage said:

View attachment 4248377

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These min./max. values are all temperature related. The highest numbers are for 25°C and the lowest are for 95°C. Other numbers are for nom. temp which is 65°C with no heatsink.
When the strips are running hot they take only 43,7v at 1120mA and when you switch the light on with normal ambient temps they need up to 48,4v at 1120mA until they reach thermal eqilibrium. Same goes for the wattage, hot Tcase less watts and less efficiency, cool Tcase more watts more efficiency.
For this reason we want the Tcase always as low as possible.
If you mount F-strips on alu C-channels they stay around 45-50°C at 1120mA and therefor you need to calculated with >46v.
Probably ~47v per strip and 48v when switched on.

Randomblame said:

These min./max. values are all temperature related. The highest numbers are for 25°C and the lowest are for 95°C. Other numbers are for nom. temp which is 65°C with no heatsink.
When the strips are running hot they take only 43,7v at 1120mA and when you switch the light on with normal ambient temps they need up to 48,4v at 1120mA until they reach thermal eqilibrium. Same goes for the wattage, hot Tcase less watts and less efficiency, cool Tcase more watts more efficiency.
For this reason we want the Tcase always as low as possible.
If you mount F-strips on alu C-channels they stay around 45-50°C at 1120mA and therefor you need to calculated with >46v.
Probably ~47v per strip and 48v when switched on.

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My findings too.
C-channel, strips ran at 1125 mA.
1" heatsinks, strips at 1125 mA.

jarvild said:

My findings too.
C-channel, strips ran at 1125 mA.View attachment 4248404
1" heatsinks, strips at 1125 mA.View attachment 4248406

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34°C at 1125mA is awesome for passive cooling. Is there a fan or some other air movement? And at which ambient temps? I need to run my F-strips at half current to get the case temps in this area(1x 1" c-channels, 2mm alli thickness, 1150mm long, 2 strips per channel).
I'm using 20pcs 2ft. single row strips and they get only ~450mA now so each diode is running with only 50mA. Efficiency is outstanding high and the whole fixture stabilize at only 4° above ambient temps. Only the COB bars run a little higher and and have a temp Δ of ~10° over ambient. But these 4 COB bars are bigger, have more fins and run with ~60w. 2 F-strips only take ~20w @450mA.

Ambient in my rooms never go over 24c, even running LED's. No fans on the fixtures them self but there are fans in the room for circulation on the canopy.
One of the reasons I went with strips over COB's, as I'm not a fan of thermal properties required to keep them cool.

Thank you gentlemen for dropping in and clarifying, really do appreciate it.