Photocells are devices that detect ambient light levels and automatically turn lights on or off accordingly. They are commonly used in outdoor lighting systems to conserve energy and reduce light pollution. However, the effectiveness of a photocell depends on its location. In this article, we will explore where a photocell should be located for optimal performance.
The location of a photocell is crucial because it must be exposed to natural light during the day and shielded from artificial light at night. According to Leviton, a leading manufacturer of electrical devices, the photocell should be mounted on the roof or another location that is exposed to full daylight and not directly exposed to any night-time illumination. The photocell must be mounted horizontally, facing north, with the hooded portion on top.
The location of a photocell also depends on the type of lighting system being used. For example, if the lighting system is being used to illuminate a parking lot, the photocell should be located near the edge of the lot, facing away from the lights. This will ensure that the photocell is not affected by the light from the fixtures and that the lights are turned on when necessary.
Fundamentals of Photocell Placement
Purpose of a Photocell
A photocell is an electronic device that senses the amount of light in its surrounding environment. It is used to automatically turn on or off lights, depending on the amount of natural light present. The primary purpose of a photocell is to save energy by reducing the use of artificial lighting when natural light is sufficient.
Optimal Photocell Exposure
The optimal exposure for a photocell is an area that is shaded from direct sunlight but still receives enough natural light to function properly. If a photocell is exposed to direct sunlight, it can cause the lights to turn off during the day and turn on at night. This can be a safety hazard, especially if the lights are used for security purposes.
Common Photocell Locations
Photocells can be installed in a variety of locations, depending on the intended use. Some common locations include:
- Wall-mounted: Wall-mounted photocells are typically installed on the exterior of a building. They are commonly used to control outdoor lighting, such as security lights, floodlights, and landscape lighting.
- Ceiling-mounted: Ceiling-mounted photocells are typically installed in indoor areas, such as offices, classrooms, and warehouses. They are commonly used to control the lighting in these areas and can help save energy by turning off lights when the room is not in use.
- Pole-mounted: Pole-mounted photocells are typically installed on light poles or other structures. They are commonly used to control streetlights and parking lot lights.
In general, the location of the photocell should be chosen based on the intended use and the amount of natural light in the area. For example, if the area is heavily shaded, a wall-mounted photocell may be more appropriate than a pole-mounted photocell. Similarly, if the area is well-lit, a ceiling-mounted photocell may be more appropriate than a wall-mounted photocell.
Installation Considerations
When installing a photocell, there are several key considerations that should be taken into account. These include avoiding direct artificial light, choosing the right height and angle for installation, and taking into account environmental factors.
Avoiding Direct Artificial Light
One of the most important considerations when installing a photocell is to avoid direct artificial light. This can interfere with the operation of the photocell, causing it to turn lights on or off at the wrong time. To avoid this, it is important to install the photocell in a location where it will only be exposed to reflected light. This can be achieved by choosing a location that is shielded from direct light sources, such as streetlights or car headlights.
Height and Angle for Installation
The height and angle of the photocell are also important considerations. The photocell should be installed at a height that is appropriate for the area being illuminated. For most applications, a height of between 6-8 feet is recommended [1]. Additionally, the photocell should be angled in such a way that it is facing the area that will be illuminated by the lights. This will ensure that the photocell accurately detects changes in light levels and turns the lights on or off as required.
Environmental Factors
Finally, it is important to consider environmental factors when installing a photocell. For example, extreme temperatures can affect the performance of the photocell. Therefore, it is important to choose a location that is not exposed to extreme temperatures or direct sunlight. Additionally, it is important to ensure that the photocell is protected from moisture and other environmental factors that can cause damage.
By taking these considerations into account, it is possible to install a photocell that will accurately detect changes in light levels and turn lights on or off as required. This will help to ensure that the area being illuminated is safe and secure, while also minimizing energy consumption and reducing costs.
