jahilliard
Senior Member
I'm trying to do a VD calculation for some pole/parking lot lights. The LED lights show them to be 89 watts at max input watts. Do I need other info due to the fact they are LED or can I use the 89 Watts for the calc?
I'm trying to do a VD calculation for some pole/parking lot lights. The LED lights show them to be 89 watts at max input watts. Do I need other info due to the fact they are LED or can I use the 89 Watts for the calc?
It's very dependent on manufacturer. I've seen LEDs with 85% input PF, but I've also seen them with 70% input PF. My first recommendation would be to contact the manufacturer and ask for their technical department -- they should be able to tell you the input PF or input amps. I usually have pretty good luck going that route when information isn't listed on the cut sheet. Be prepared to spend some time on hold, though. Also, this approach is very dependent on who the manufacturer is and how helpful/knowledgeable their people are.hmm....I don't see an actual PF available. I'm under the impression 80% would be a fair estimate??
If the "white" LED uses a combination of several different colored LED dies, then it may change color somewhat when the driver goes out of regulation at the dim end. The different colors may have slightly different minimum voltages.So if there is drop in voltage, say from 120 to 105, what could potentially result as far as the LED light itself? would it become dim, change color slightly, flicker?? I'm curious if anyone has actually tested or experienced what happens.
130829-2115 EDT
steve66:
Interesting.
On the small LED I tested RMS current is close to constant, about 0.1 A, from 60 V thru 140 V with sine wave excitation. Power and light output does vary with voltage.
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