Daytime parking lot lights will typically be lights that are connected to a lighting control problem. Energy costs are unnecessarily high and fixtures may be shortened by needless daytime operation.In many cases, the LED fixture itself isn't the problem. Common causes include faulty or incorrect dusk-to-dawn photocells (dusk-to-dawn sensors) and incorrect control setting.
This guide details how photocells operate, why parking lot lights are left illuminated during daylight and how to test automatic dusk-to-dawn operation.
How Does a Photocell Work on Parking Lot Lights?
A photocell (also known as a dusk-to-dawn sensor) is a device that automatically regulates outdoor lighting, depending on the level of ambient light.
As ambient light falls to a lower level than the photocell needs, at night, the fixture will turn on the lights. Upon the return of daylight, the sensor captures enough light, and turns the lights off.
Photocell operation is often added as an option to the modern commercial LED parking lot lighting system so it can be used in a variety of applications. Users can select manual operation, external controls or automatic dusk to dawn lighting.
Common Reasons Why Parking Lot Lights Stay On During the Day
The following problems could be indicated by the lights in the parking lot that are illuminated during daylight hours:
Cause 1: Photocell Function Is Not Activated
Several LED parking lot lights come with an optional photocell. The photocell opening can remain covered when automatic dusk-to-dawn operation is not needed. Fixtures with an optional photocell sensor require the sensor function to be enabled for automatic operation.
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The black cap cover will prevent the photocell function from operating.
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The built-in dusk-to-dawn photocell sensor is activated when the black cap cover is removed.
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Once energised, the fixture will automatically adjust to surrounding light.
Lights that work normally but stay on during the day may need the photocell function checked and enabled.
Cause 2: Photocell Sensor Is Blocked or Dirty
Photocells use ambient light to be detected. Dirt, dust, bird feces, leaves or other clogging material will diminish the amount of light reaching the sensor.Insufficient ambient light may cause the sensor to detect nighttime conditions and keep the light on.
Check the following:
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Use soft cloth to clean photocell lens.
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Remove any objects blocking direct exposure to daylight.
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Make sure other buildings or plants near the building are not casting too much shade.
Cause 3: Incorrect Installation Location or Orientation
Photocell sensors require proper exposure to ambient light in order to function properly.
Avoid installing fixtures where the photocell is:
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Surrounded by buildings.
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Strong lights from manmade sources.
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Planted in spots where there is shade 24/7.
An improperly installed sensor may detect the wrong light level and delay the ON/OFF response.
Cause 4: External Lighting Controls Override the Photocell
Commercial properties may utilize a number of lighting control techniques, such as:
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Timers
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Central lighting controllers
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Motion sensors
In the case of an external control system, it can take over the function of the photocell and maintain lights on at a preprogrammed time.
Review the control settings for any other system that may be controlling the fixture.
Step-by-Step Troubleshooting Guide
Before replacing the fixture, perform a few simple checks to identify the cause.
Step 1: Confirm Photocell Activation
Action:
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Always switch off electricity prior to inspection.
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Ensure black cap cover is in place over top of photocell opening.
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For automatic dusk-to-dawn operation, remove the black night cap.
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Reconnect power and check the functioning of the fixture.
Result:
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A light that responds to changing light conditions indicates the photocell was switched off.
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A light that remains on requires further troubleshooting.
Step 2: Clean and Inspect the Photocell Area
Action:
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Shut off electricity at the circuit breaker box.
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Check the sensor region for dust, dampness, cracks or damage.
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Thoroughly clean the surface of the photocell.
Result:
A fixture that turns off after cleaning may have had its sensor blocked from detecting daylight.
Step 3: Perform a Daylight Simulation Test
To test the photocell operation:
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Find the photocell sensor.
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Completely cover the sensor (like at night).
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Take off the lid and set it in bright light.
A short response delay may be required when considering the fixture design to avoid switching unwanted lights due to temporary light changes.
How to Properly Use the Optional Dusk-to-Dawn Photocell Feature
For commercial LED parking lot lights, with an option for photovoltaic cells:
For automatic lighting control:
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Remove the black cap cover.
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Ensure that the photocell sensor can see light from the surrounding area.
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Let the sensor do the automatic control of ON/OFF switching.
In case of any other forms of control:
Keep the photocell sensor blocked, and go for other means of control like:
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Building automation systems (BAS)
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Timers
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Smart lighting controllers
Thus, a variety of choices for lighting control options is provided to the users.
Benefits of Using an Automatic Photocell on LED Parking Lot Lights
A correctly set-up dusk-to-dawn photocell offers the following benefits:
Energy Savings
The light switch will only work at night, thus no energy will be consumed during the day.
Less Maintenance
Since everything works automatically, the maintenance is minimized and the useful life of LED fixtures increases.
Convenience
No manual operation is required. Lighting adjusts itself according to the natural daylight.
Versatile Installation Possibilities
Thanks to the optional photocell function, people can set their own conditions for lighting control depending on commercial environment.
Conclusion
In case your parking lot lights stay on during the daytime, the problem may not be related to fixture failure. First, check whether the optional photocell function is enabled, the sensing area is clean, and no external factors are affecting its operation.
Demilare LED parking lot lights include the option of dusk-to-dawn photocell function which makes it possible to turn on automatic control of lights in case you need it. All you have to do is to take off the black cover and the sensor is ready for use.
Check out the whole collection of commercial LED parking lot lights with optional dusk-to-dawn photocell function.![]()
