Can anyone tell me if modern fluorescent tubes and or electronic ballasts are adversely impacted by excessive switching? The issue is, will motion sensors on individual fixtures lead to reduced tube or ballast life expectancy?
The issue is, will motion sensors on individual fixtures lead to reduced tube or ballast life expectancy?
How exactly are you getting $1.22 savings in electric costs?add example:
20,000 hour lamp, $1.50, 34 watts, $0.10/kWh electric rate.
with a 3.1833 minute on off cycle, the lamp hours are reduced to 3,694 with 6,777 lamp cycles, saving $1.22 in electric costs offset by $1.22 in reduced lamp life.
Well, it came with no money-back guarantee, but I looked back on what I scratched out. Whether or not it makes sense today is another story, but it sounded good last night .How exactly are you getting $1.22 savings in electric costs?
There is a lamp life graph here (figures 4 & 5):I had some chart somewhere showing lamp life vs switching frequency ... It was a very linear relation ship between switching frequency and lamp life.
I don't think the number of cycles has any direct affect on the total energy use. I wouldn't suggest using an equation like this to determine energy savings with occupancy sensors.Here is what I actually did:
# of lamp cycles for the reduced time:
#cycles = A1/(h1-h2) = Lamp life / run time reduction
what I called the "Electric savings":
h2*watts/1000*$/kWh*#cycles =
Electric cost per reduced time cycle * #cycles for the reduced time
They certainly put more thought in it than I did. I saved it so I can read it when I have more time. Thanks for the link.I found a study done on energy savings with occupancy sensors...
not that I know of.090421-1915 EST
mivey:
Do you have a comparable curve for 8' Slimlines?
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