OK sparkies, can you solve this one?
-Two adjacent 5-unit apartment buildings on separate electric meters.
-Photocell switches controlling walkway/stair landing fluorescents as well as sodium vapor lights in the alley ; total load about 600W on one and 1070W on the other.
-In service for 20 years; failed on the same day last week.
-Circuit breakers had not tripped.
-line voltage to both controllers reads 120V; voltage on load side of controllers 0V.
“OK”, I say to myself, “must have been a voltage spike from Edison that disabled the sensors.”
I bought two new 2000W controllers (http://www.amertac.com/), installed one of them, put tape over the light sensor window, and the lights came on, all except two, which I figured must have had burned out bulbs.
I then replaced the other sensor and its lights came on. Great, so I buttoned up the boxes where the connections were made and took off the tape and the lights went off just as they should.
I changed bulbs in two fixtures and taped the sensor to make it turn on, but nothing lighted, not even the lights that had worked before. I taped the other sensor and its lights did not come on either.
So, 20 years without problems, then simultaneous failures on different circuits fed by different meters. Replacement controllers work once but will not switch on again after the first test run. Amertac customer support has no idea; my problem is not part of her script. They say maybe out-of-box failure; return the units to HD.
Two identical failures following similar failures of the original devices suggests something other than out-of-box failure to me.
Any ideas?
Replies
those stupid lights
i've spent more time fooling with those
worst is when they're on a 3-way
get call-back after callback... sensors... internal switches... time delay
brrrrrrrr... i hate 'em
Open then up and see if you can see a failure mode.
I would measure the voltage.
And I would bypass then and measure the current.
Could be poltergise.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
"Open then up and see if you can see a failure mode."What would I look for, poltergeist droppings? What's in there, anyway, some sort of relay, I assume?"And I would bypass then and measure the current."I have a Fluke meter that can measure amperage, but what would you expect I might find? The 15A circuit breaker should limit amperage to below the 2000W service rating of the device. BruceT
The ones like that I have seen are fairly simple with a cadmium sulfide photocell and a bimetalic switch with small heater.http://en.wikipedia.org/wiki/PhotoresistorWhen the sun is out the resistance decrease and heats up the switch and it opens.When you first turn power on the heater is cool and the switch is closed for about 1-2 minutes. That is a way to the light during the day.But you need the power to be off 5-10 minutes for it to cool off.There is no "programing" on them.This is a spec for a CS cell. But probably nothing like the one in the unit.http://www.engineering.uiowa.edu/~ece195/2005/labs/pdvp9001.pdfTrying to think of the failure modes.If it tried to close on a extreme load the switch or terminals might be vaporized. Another possibility is that the CS cell shorted. I don't know if a voltage spike could do that or not.Common time inverse breakers will allow large amounts of current for short times without tripping. That is why you can run a 1 1/2 table saw on a 20 amp circuit. It might draw 80-100 amps on startup.You should be able to measure the resistance of the cell and of the heater if you can get it appart without destroying it..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bypass the control unit with a switch and make sure all works. With the lights on check the voltage and currant flow, you might have a failing neutral causing the controllers to "pop".
Try removing lamps, this should only effect currant reading, voltage should stay the same. This should help you track down the problem.
"...you might have a failing neutral causing the controllers to "pop"."Failing neutrals that suddenly showed up in two different circuits in separate buildings on separate meters?"Try removing lamps..."What is your suspected culprit? Why would defective lamps have caused the same problem at the same time on two different systems?That's why this thing baffles me. The cause would seem to be something that affects photocell controllers but not anything else and probably outside the house wiring systems since it occurs in two different buildings at the same time.BruceT
Like I suggested above, I suspect that a power glitch may have "programmed" the original controllers, and flipping switches may have done the same to the new ones.
Corporation: n. An ingenious device for obtaining individual profit without individual responsibility. --Ambrose Bierce
I'm thinking along the lines of a common supply somewhere. Are these two buildings near to each other feed from different breaker panels? I'm thinking bad connection somewhere causing a surge.
The buildings feed from different Edison Co. meters.
BruceT
Keep in mind that many of those units have a "secret code" -- if you switch them on and off rapidly two times it turns the light on in the day, eg, and on and off rapidly three times turns the light off at night.
So try simply turning both units off at the breaker (or any switch ahead of the control) and leaving them off for a minute or two, to reset things.
This is not a porch light controller. There is no code on this thing. (http://www.amertac.com/)When it sees light, it switches the circuit off. When it sees no light, it switches the circuit on.I'm beginning to think space aliens are taking control. I may make little tinfoil hats for the controllers to block those cosmic signals.
BruceT
Not a sparky ... but I think I've found your problem:
View Image
LOLBruceT
http://www.amertac.com/content/products.nsf/Lighting%20Controls%20&%20Dimmers/Direct%20Wire%20&%20Commercial%20Controls/AT15BC/pAt15BC.htm
Is that the one you purchased?
I can't help with your problem, but I'm wondering if you might be able to help with mine.
Can you recommend a motion detector controller for two 500w halagen lights? I want dusk-to-dawn motion detection. I have had several units from RAB and they seem to last about two years. I'm not sure what is going wrong with them. I may switch to 300w bulbs.
You sure they are halogen and not HID? HID would have problems w/ e.g. motion sensor, halogen should not (I think). Halogen is a type of incandescent (non ballasted).
That is a good question. The light bulbs are those little tubes with the contacts on the end. The fixture has spring contacts. Like these:
http://www.1000bulbs.com/4-in.-Double-Ended-Recessed-Single-Contact/So I take that to mean halogen. In part I got those because my work lights take the same bulb. If I need to replace the fixtures (yet again) I will, but these things are up about 20' and a pain to get to. So I want something that will keep working.
hmmm ... dunno. I THINK the halogen should be OK w/ a motion sensor. Couldn't open your link (i.e. it led nowhere). If the lamp has a pin/contact on both ends, I think that means it's a halogen. Ultimately a call the the lamp manuf tech rep may answer your question.
Edited 10/31/2008 7:09 am ET by Clewless1
Follow up on my first reply.
I pulled the instruction sheet on an Intermatic photo cell. About the same as the one you installed.
The trouble shhoting chart shows two possible cause:
(1) photo control damaged by lightning or other high energy transient. (likley the cause of the first ones failure)
(2) With high pressure sodium or mercury vapor you can be experienc the trouble from the end of-of-life failure of the lamp and/or ballast.
A third possible is to high a line voltage. this would cause the photo cell to fail in the off mode.
You replaced two hps bulbs, you said. You may have additional bulbs at the end of thier life or a ballast or sevral also reaching that point.
I replaced fluorescent Edison medium base bulbs. The HPS were still working.Where did you find the trouble-shooting info? All I found on their site was the same thing that came in the package; mentioned line voltage surges (failing in on, not off position) but nothing about HPS.BruceT
Edited 10/30/2008 2:36 am by brucet9
We have sevral different photo cell brands in our stock cabinet. The Intermatic was the closest one to what you have. I just pulled the instruction sheet out of one.
The Intermatic fail on when line voltage is too low, according to thier trouble shooting chart.
Had another thought. Is thier a lighting contactor on either or both of those circuits?
We have them on most of out exterior lighting circuits. One or two of them are fused. If you have one, a blown fuse in the contactor circuite could be the problem.