Trouble with a receptacle/photocell

Old 12-07-12, 11:07 PM
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Trouble with a receptacle/photocell

Hi there,

We moved into a house in April and recently putting up Christmas lights, I plugged two strands of lights into an exterior receptacle via a 20' exterior extension cord. This was the first time using this particular receptacle. When first plugging it in, it worked fine. This was about 7:00 pm and it was dark. I go outside later that evening around 11:30 and the lights are not lit. I tried the second outlet, but they still were not lit. Figured maybe there was a blown fuse in the lights, but before checking I tired plugging them into a different receptacle, and when doing that they worked fine.

Directly below the receptacle that was not working was another "receptacle box," but without outlets. Instead, one hole with this screwed into it:

Intermatic K4121C - Photo Control - Thermal Type Photocell - Stem Mounting - Dusk-To-Dawn - 120 Volt |

That was last night, and tonight I tried the same thing. Plugged them in at 8:30 pm and they worked. Unplugged them, then came back at 1 am and tried them again, nothing.

Looking it up says that it is a dawn to dusk photo cell. My goal is to be able to use the receptacle for plugging in the lights, and I have a few questions:

1. Would the photo cell be controlling the power for the outlets?
2. If it was dusk to dawn, why would the outlet not be working while it was dark? It worked at first in the dark, but then later it did not.
3. Can I just disconnect the photo cell? And how would I do that?

I know next to nothing about this stuff, so i really appreciate any help given.
Old 12-07-12, 11:52 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
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If someone was smart enough to wire a photocell in to the receptacle where the Christmas lighting would plug in then that someone may have also installed a time clock to turn the receptacle off at a specific time. In other words, the receptacle would go live when the sun went down and then go dead at say 11 PM.

Look inside for a time clock.
Old 12-08-12, 05:14 AM
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Like Furd said.....look for a timer.....especially if it goes off at the exact same time.

If no timer......then try to give the photo-cell a few good taps with a screw driver handle.

These can go bad and end up with erratic operation.....I've had to replace 2 in the past.

Do it when it's off (but should be on).....if it flickers or comes on then it's the cell.

Also.....make sure there is not another light source close by that might be turning it off.

A porch light or spotlight could be fooling it if the "eye" is facing in that direction.

Removal is simple if so has a white (neutral) and red & black switching wires.


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