Table of Contents

• Introduction
• Why Sensor Orientation Matters?
• Differences Between Northern and Southern Hemisphere Orientations
  • Northern Hemisphere
  • Southern Hemisphere
• Recommended Orientation for Photocontrols
  • Avoid Direct Sunlight
  • Minimize Light Interference
  • Directional Indicators on Photocontrols
• Best Practices for Different Settings
  • Residential Applications
  • Commercial and Street Lighting
• Conclusion
• References

Meta description

Learn why photocell sensor orientation differs in the Northern and Southern Hemispheres, and discover best practices for reliable, efficient lighting control in various settings.

Introduction 

Photocontrol devices are essential for automatic lighting control. They make sure that the lights respond efficiently to the ambient light levels and are switched on and off accordingly. However, for the photocells to perform at their best, they need to be installed with the perfect orientation in mind according to their location.

Photocells will need to be placed with different orientations for each hemisphere to make sure they receive optimal sunlight so that they can lead to consistent, uninterrupted light. To ensure the best performance from the photocell devices, users need to make sure they follow the directional indicators on the sensors and install the photocells accordingly. This article will explore the importance of proper sensor orientation, the recommended orientation with the differences between the Northern and Southern Hemispheres, the role of directional indicators on photocontrol, and best practices for installation.

Why Sensor Orientation Matters?

The orientation of the photocontrol sensor head directly affects its accuracy in detecting light. A wrongly positioned photocell head might not give its best performance as it might not receive the optimal amount of sunlight. This can lead to the lights switching off and on at unintended times or the unwanted flickering of lights. The sensors will perform to their best and provide continual, uninterrupted light only when they are placed according to the recommended orientation where they receive just the perfect amount of ambient light without interruption.

Differences Between Northern and Southern Hemisphere Orientations

Depending on where the photocells are intended for use, the positioning and orientation of sensor heads will vary. It is different for the Northern and Southern hemispheres owing to the difference in amount of light incident on them. Let us have a look at what is the perfect alignment of photocell sensors for both hemispheres.

Northern Hemisphere

In the northern hemisphere, it is generally recommended to face the sensors northward or towards a shaded side for the following reasons.

• Direct exposure to glaring sunlight can result in the misreading of the ambient light levels by the sensors. This can result in untimely switching on and off of the lighting units, they might turn off too early and fail to turn on at the intended time.
• In the Northern Hemisphere, north-facing sides receive lesser light, and hence the results are expected to be more consistent when the sensors are either facing North or towards a shaded side as they are spared from direct glare and shadows.
• Facing the sensors northward also reduces the risk of overheating. The sensors may get overheated after prolonged exposure to sunlight, thus compromising their longevity and accuracy.

Southern Hemisphere

In the southern hemisphere, since the sun is on the north of the equator, positioning the sensors towards the north would mean exposing them to too much of sunlight. This is avoided and the photocell sensor heads are positioned southward due to these reasons:

• Too much glare can cause the sensors to miscalculate the intensity and give inconsistent results. They might turn on the lights too early at dusk or may not turn them off in time during the dawn. For a consistent and timely result, sensors should face southward to avoid too much exposure.
• Facing the sun for too long on daily basis reduces the lifespan of the photocells due to overheating and hence they should receive a consistent but lower amount of light.
• For more reliable performance, photocell sensors should receive moderate sunlight and should avoid shadows. Hence they are positioned southwards in the southern hemisphere.

Recommended Orientation for Photocontrols

Here are some of the points to keep in mind during the installation of photocontrols to make sure they deliver their best performance and are protected against too much exposure that can be damaging.

Avoid Direct Sunlight

Whether in the Northern Hemisphere or the Southern Hemisphere, the sensors should be positioned in a way that they do not receive direct sunlight. Facing them opposite to the position of sun means they receive indirect light and the risk of overheating is significantly mitigated. Hence, the lifespan and performance of the sensors will be enhanced.

Minimize Light Interference

Make sure that your photocell sensors are not facing a source of artificial light. This is because the sensors may confuse the light with the ambient light and deliver inconsistent results due to false readings.

Directional Indicators on Photocontrols

Some manufacturers provide photocell sensors with directional indicators marked on them. It is always recommended to follow these indications during the installation of photocontrol cells. This will ensure optimal performance in accordance with the geographical location they are being installed.

Best Practices for Different Settings

Residential Applications

• While installing photocells in residential areas, make sure they aren’t installed near reflective surfaces like windows to avoid reflections that may generate false responses due to miscalculations about the light intensity.
• Do not face the photocells directly towards the sunlight to avoid overheating.
• Avoid installing the sensors at places where they are under the shadow of trees or other houses so that there are no shadows or obstructions to sunlight.

Commercial and Street Lighting

• Position the sensors on the top of lamps or on their sides to avoid exposure to other adjacent lamps. This will help avoid false readings from other lights in the setting.
• Similarly, in areas with high traffic, photocells should be installed high above to avoid tampering.
• Use centralized controls and grouping of the sensors for better control.
• Use industrial-grade sensors for durability.

Conclusion

Proper photocell sensor orientation is essential for optimal performance and longevity. In the Northern Hemisphere, sensors should face north or a shaded side, while in the Southern Hemisphere, southward placement is ideal to avoid direct sunlight, glare, and overheating. Following best practices, such as avoiding reflective surfaces, minimizing artificial light interference, and adhering to directional indicators, ensures reliable and efficient lighting control across residential, commercial, and street settings. Thoughtful installation enhances energy efficiency and reduces maintenance, making it a critical aspect of lighting automation.

References

• https://www.sciencedirect.com/topics/engineering/photocell#:~:text=A%20photocell%20or%20photoresistor%20is,light%20will%20cause%20higher%20resistance.
• https://leaditop.com/wire-in-controllers/
• https://www.britannica.com/place/Equator#:~:text=The%20Equator%20is%20the%20imaginary,line%20with%200%C2%B0%20latitude.
• https://leaditop.com/product-category/product/zhaga-control/zhaga-sensor/