When it comes to light controls, photocells or photosensors are the most common. Photocells or Photosensors are wired to the same circuit as the light fixture(s) and controls when the light turns on and off. Most commonly the sensor is mounted to the light fixture or light pole and receives constant power. When the sensor detects sun light it will switch the light fixture off, and when it no longer detects that sun light it will then power the light back on.
It’s important to know which photocell or photosensor is right for your job, and a basic breakdown makes that choice simpler. There are three main types of sensors which are button, stem, and locking. The most basic sensor being the button style, which is installed inside the light fixture with it’s sensor stem mounted through a knockout. That sensor stem is how the photocell senses the light levels. The stem photocell is a step up in terms of capability. Unlike the button photocell the stem photocell is capable of being installed directly to a light fixture as well as remotely. Button photocells, when wired appropriately, can control more than a single fixture at once. The stem photocell mounts much like the button photocell but is typically larger with a longer sensor stem. The third option is the locking photocell which is installed by a twist locking system. This is accomplished by the fixture having a special receptacle located on the top of the fixture. With the locking style you find the benefit being much more serviceable when issues arise. Twist-lock photocells are typically installed only in pole-mount area lights specifically designed for these photosensors.
Closely related to the desire for photocell lighting controls is the ability to dim your lighting fixtures. The most common dimming is the “0-10V Dimming” standard. The ability to dim a light fixture comes from a specific power supply that is able to limit the power going to the LEDs. A non-dimming power supply is always providing full power to the LEDs. A dimming power supply compared to a non-dimming power supply will have 2 additional communication wires. These additional wires control the amount of power that is being sent to the LEDs. There is no physical resistance provided to the circuit by the dimming wires. The 0-10v dimming wires are control wires that serve to communicate the intended brightness level.
One of the most important aspects of selecting the right controls is always voltage. When selecting a photocell or photosensor you need to know the current circuitry that the light is being wired to. Most of Jarvis’ lighting fixtures are 120-277v compatible, however lighting controls can tend to be a little more specific. A 120v rated photocell would not work in a 277v circuit. When it comes to dimming controls, as stated above the most common commercial dimming power supply is 0-10v. Your dimmer switch needs to be compatible. Another important note of the 0-10v dimmer is that the voltage may seem backwards because the higher the voltage going in means the dimmer the fixture will be. 0V going in means the fixture is 100% lit up, while 10V in the dimmer would be completely off.