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Help resolve a simple dispute

  1. Sep 11, 2008 #1
    :Scenario: you have a parking pole light, photo cell and analog timer. Which order would be more beneficial when installing the photo cell and timer to the light? Photo cell first or timer first?

    I chose timer first because of the benefit of energy saving. I figured you set the timer at when ever you have sunrise and sunset. Now the benefit of having the photo cell would be that you would'nt have to reset the timer due to season change and daylight savings. Can anybody see a benefit of installing the photo cell first?

    I would think this is a pretty simple question but maybe I'm missing something and would love to get your 2 cents on this question.
  2. jcsd
  3. Sep 11, 2008 #2


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    Since you say the point is to turn the light on when it gets dark and off when it is light out and you have a photocell, I'm kind of at a loss as to why you would want a timer at all.

    The only purpose I can see in having both photocell and timer is if you want the light to turn on at dark and then shut off after a while and before it gets light out again.

    Edit: Just what energy saving is the timer supposed to provide?
  4. Sep 11, 2008 #3
    Your exactly right. I don't see the need for a photo cell but the plan calls for photo cell and timer. I'm trying to figure out why they would call for both device. The only reason I could imagine is that they want to turn off the light at a certain time at night as ( No Time) stated. But shouldn't the lights always be on in a parking lot. Parking is for a post office but I have never seen a federal buildings parking lot let alone any parking lot with lights off after hours.
  5. Sep 11, 2008 #4


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    For the stated purpose I would think the photocell would be better.
    The photocell will automatically adjust the lighting times as needed.
    Including weather conditions where ambient lighting can be greatly reduced.

    The timer idea seems better suited for residential purposes where you want the light on when you get home, but there is no need to run them all night.
  6. Sep 11, 2008 #5


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    Sounds like something the goverment would do. Turn the lights on at dusk with the photocell then after the office closes, lights off with the timer; saving energy for the rest of the night.
  7. Sep 12, 2008 #6
    I guess it was that simple. I just made it bigger than it was. Thanks for your replies.
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