karaba
Member
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- philippines
kinda new with led lighting.... i have a 60x60 led light 36watts 10pcs connected, my question is what would be the total load in kva. thank you
led lighting calculation
- Thread starter karaba
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- Lockport, IL
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- Semi-Retired Electrical Engineer
I don't know what you mean by "60 x 60." But if one item draws 36 watts and you have 10 of them, then the load is 360 watts, or 0.36 KVA. An LED light is a purely resistive load. So it has a power factor of 1.0. Thus, its value in watts is the same as its value in VA.
winnie
Senior Member
- Location
- Springfield, MA, USA
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- Electric motor research
Charlie,
An LED is far from a resistive load. LED fixtures that connect to mains require driver electronics which likely include an input rectifier. The power factor of an LED fixture will depend on the design of that input rectifier.
Many (most) modern LED drivers will be designed for a power factor very close to 1.0, but likely not exactly 1.0.
-Jon
An LED is far from a resistive load. LED fixtures that connect to mains require driver electronics which likely include an input rectifier. The power factor of an LED fixture will depend on the design of that input rectifier.
Many (most) modern LED drivers will be designed for a power factor very close to 1.0, but likely not exactly 1.0.
-Jon
Electric-Light
Senior Member
He must mean 60cm x 60 cm, or a 2' square troffer. Both of you are both right and wrong.
Short answer is to go by the amperage label or manufacturer's recommendation.
Long answer is....
LEDs and fluorescent lamps are very similar as a load.
The LED ballast determines how it presents itself to the line and the ballast design depends on local regulations and business-political environment. 36W LED can be anywhere from 36-72VA, ASSUMING there is no active LED deterioration compensation. There are fixtures actively compensate as LEDs degrade and boost the power to maintain the output and input could go up to as much as 100VA (50W) (to compensate to provide 100% output after LEDs have degraded to 70% requires 1.42 x the power)
The power factor can be anything from 0.5 to 1 hence the wide variation above.
In the US, CFLs are usually 0.5-0.6.
LED bulbs are above 0.7, because of indirect implicit regulatory effect of Energy Star. Energy Star label is not a requirement in order for lamps to be sold legally, but its often a condition of rebates or local codes that it is an implicit requirement. Lamps that do not qualify for Energy Star usually don't qualify for subsidies, which means that they'll be more expensive.
Externally ballasted T5 and T8 lights are almost 1.0 but those marked "for residential use only" can be 0.5-0.6. Externally ballasted LEDs can be assumed similarly.
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