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How to Add a Photocell to an Outdoor Light

If your outdoor lights turn on too early in the morning or do not turn on automatically, you can install a photocell to solve this issue.

Automatic lighting uses photocell sensors to detect how much ambient light there is. Installing a photocell to outdoor light is a great way to keep your home well-lit and save on energy costs.

In this blog post, I will explain how to add a photocell to an outdoor light and give tips on how to get the best out of your photocell.

Table of Contents

What is a Photocell?

How To Add a Photocell to An Outdoor Light

A photocell is an affordable gadget that detects light to activate or deactivate your lights. Photocells are used in several outdoor lighting fixtures. For instance, if your outdoor lights automatically turn on at night, then a photocell controls this function.

At dusk, your photocell will sense that there is no sufficient light around to switch on the outdoor light, so it transmits a signal to your outdoor lights and turn them off.

When there is sufficient light in your area, the photocell sends signals to switch on the outdoor lights again. Photocells can also be used for other outdoor functions, including; turning your lights on during daylight hours when it’s rainy, controlling light sensitivity, and turning on lights that are far to be turned on with an ordinary wall switch.

How Does a Photocell Work?

A photocell functions with electricity and light waves, just like your eyes. A photocell comes with a small strip of special metals and materials. When light hits these metals and materials, it brings resistance between them and produces electricity.

The electric current sends a signal to turn on your outdoor light when there is insufficient daylight. A photocell functions in reverse; when there is too much daylight, it will turn off your outdoor lights. These devices are very sensitive to light and will activate them even when there is a small amount of light.

If a photocell turns on with sufficient daylight, it may not be shaded enough or covered. You can fix this problem by covering the photocell with a covering or shade. If the photocell activates when it’s rainy, cover it with a waterproof material.

Related: How To Wire a Photocell to Multiple Lights

Materials You Need to Install a Photocell to an Outdoor Light

  • Wire strippers
  • A new photoelectric switch
  • A screwdriver
  • Needle nose pliers
  • Electrical tape
  • Silicone sealant
  • A voltage tester
  • Wire nuts

Benefits of Adding a Photocell to Your Outdoor Light

  • Environmentally friendly and saves electricity
  • Easy installation and no rewiring or maintenance are required
  • Saves on the cost of outdoor light replacement
  • No electrician is needed, and no wires to run

Step-By-Step Instructions for Adding a Photocell to An Outdoor Light

Here are some steps to help you install your photocell on an outdoor light. This process needs some electrical knowledge, so if you don’t feel safe or confident, just contact an electrician to install it for you:

  • Turn off the power to your outdoor lights. If you are not sure which breaker powers your outdoor lights, switch off all breakers in your building to cut off all power. Turn on the switch to the outdoor light to check if the power is off.
  • Disconnect the housing of the existing outdoor light fixture. Ensure you document how you disassemble it so it can be seamless to put it back together.
  • Look for two black wires on your photocell. These black wires should be tapped into the black wires running between your building’s main power and the light fixture. Disconnect the black wire coming from the light fixture to the house.
  • Connect one black wire on your photocell to the black wire coming from the house. Ensure you twist the naked copper wire to form a tight connection.
  • Join the second black wire on your photocell to the black wire on the light fixture and ensure that the copper wire is twisted properly.
  • Cover the connections with electrical caps and ensure that the caps are tight around the copper wires.
  • Tape the new connections with electrical tape and ensure all copper wires are taped.
  • Turn on the power at the breaker and test the photocell. Ensure the light switch is on and cover the photocell with your hand. If your outdoor lights turn on when you have covered the photocell, the connection is fine.
  • Complete the installation by fixing the light fixture together


Installing a photocell to your outdoor lights is one of the best ways to save money and energy. The installation process is easy and can be done in minutes. However, you need some tools and supplies to make the process easy. Since there are several types of photocells out there, ensure you choose one that is specifically designed for outdoor use.

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