# Exterior lights flashing



## WTB (Jun 3, 2012)

Today I replaced two exterior lights with new, energy star lights. The new lights use CFL bulbs, and both utilize photocells. My plan is to leave the interior switch in the on position, and let the photocells determine when the lights need to turn on. Everything appeared okay tonight, at least initially. As it became dark, the lights turned on. However, after a couple of minutes, they both began to flash on and off. I turned the interior switch off, thinking maybe it wasn't quite dark enough for them to stay on. It's now pitch black outside, and the lights are exhibiting the same behavior. Any ideas on what might be going on would be appreciated. Thanks in advance.


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## k_buz (Mar 22, 2012)

The photocells could be seeing the light given off by the fixture. How quickly do they flash?


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## WTB (Jun 3, 2012)

The lights are on for about 45 seconds before they start to flash. The flash itself is very quick, the light is off probably about 1 second.


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## HandyAndyRR (Dec 2, 2011)

If it is a very faint flash it could be due to a small amount of power trickle. Sometimes a switch can still allow a small amount of electricy past and cause a faint flash with cfl bulbs. Switch them to an older incandesant and see it is still happens. The incandesent needs more power to light up than a cfl, so it will not exhibit the problem. If the incandesant is working normally, it is most likely the switch or photo eye allowing a small amount of power through.


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## WTB (Jun 3, 2012)

Not exactly sure how to define a faint flash, but in this case the bulb goes completely out, then comes completely back on again. I don't think I can swap an incandescent, as the fixture only takes the two-pin lights (unless I can get those in incandescent?)


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## k_buz (Mar 22, 2012)

Are the photocells built into the fixtures? Did the light bulbs come included with the fixtures?


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## WTB (Jun 3, 2012)

buz, Yes to both questions.


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## k_buz (Mar 22, 2012)

Could it be that there is a motion sensor on these fixtures as well?


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## WTB (Jun 3, 2012)

I don't think that's the case. Just looked at the manufacturer's web site, and there is no mention of it.


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## HandyAndyRR (Dec 2, 2011)

If it is coming on fully than it does not sound like what i was describing, i have only ever seen that as a very faint flash. I would think that the eye is positioned so that the light from the bulb is turing it off and then gets dark and comes back on.


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## k_buz (Mar 22, 2012)

If it doesn't have a motion sensor (you can post the make and model and we can take a peek) another guess would be to make sure the bulbs are inserted properly/completely.


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## WTB (Jun 3, 2012)

@Andy - That definitely seems to be what is happening, but I'm hoping it's not the case as that would probably be a negative statement on the design of the fixture 

@buz - Manufacturer is Hinkley. Fixtures (both) are Trafalgar, model 1314MB-EST. I'll go check the seating of the light bulbs...


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## k_buz (Mar 22, 2012)

I am looking at the fixture and they don't appear to have been manufactured with the photocell as I was assuming. Did you install the photocell? If so, where did you install it that it could not see the light from the bulb?


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## WTB (Jun 3, 2012)

The manufacturer installs the photocell when the energy star "version" of a fixture is ordered. It's installed at the bottom of the backplate.

It must be that the photocell is being impacted by the light from the fixture. The two lights I installed are both flashing, but at different intervals.


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## frenchelectrican (Apr 12, 2006)

If you did see the photocell how many conductors that goes to the photocell ?? there should be either 2 or 3 conductor verison let us know which one you have.

If you have 2 conductor verison that useally cause the issue with CFL due the photocell set up they don't work very well with electronique loads but standard load like indentscent bulb it will work just fine without flicker.

So that why I rather use the three conductor verison if possble. The reason why is due the three conductor verison the CFL electronique loads will not affect it due the netural will be at the photocell to use the power to engerized or deengerized the load.

( the three conductor verison will have black{ line }, red { load } , white {netural } conductors ) 

Merci,
Marc


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## WTB (Jun 3, 2012)

Thanks for all the help, folks. It appears the problem is with the photocells. I covered the photocells with putty, and now the lights stay constantly on. Doesn't resolve the issue, but at least I know what the problem is and can go from there. I appreciate you guys taking the time to help out!


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## busman (Nov 7, 2008)

Marc has it correct. The 2-wire devices (photocells, occupancy sensors, etc) work by passing a small amount of current thru the light bulb filament (in an incandescent bulb). This doesn't work well with CFL or LED. You need a device with a dedicated neutral. The code has now changed to require a neutral in all switch boxes in the future for this reason.

Mark


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## danpik (Sep 11, 2011)

Just wondering...You indicated that there are two of these, did you try a test with one disabled to see if the other one had the same behavior? It could be that the sensors are seeing the light from the other bulb.


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## k_buz (Mar 22, 2012)

busman said:


> Marc has it correct. The 2-wire devices (photocells, occupancy sensors, etc) work by passing a small amount of current thru the light bulb filament (in an incandescent bulb). This doesn't work well with CFL or LED. You need a device with a dedicated neutral. The code has now changed to require a neutral in all switch boxes in the future for this reason.
> 
> Mark


That really isn't the point. The point is that the manufacturer installed these photocells. They should work. I would complain that they don't.


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## busman (Nov 7, 2008)

k_buz said:


> That really isn't the point. The point is that the manufacturer installed these photocells. They should work. I would complain that they don't.


I doubt the manufacturer installed these photocells. The makers of these products do label them to indicate that they will only work with incandescent bulbs. You can't blame the electrician who installed it either, since he installed the product properly. The only solution is to have at least one incandescent bulb on that sensor. The rest can be CFL or LED.

Mark


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## k_buz (Mar 22, 2012)

You didn't read the entire thread...



> The manufacturer installs the photocell when the energy star "version" of a fixture is ordered. It's installed at the bottom of the backplate.


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