MH Controls Corner: In-Fixture Lighting Controls

May 20, 2020

Integration, integration, integration! It is the path to efficiency and economy, and is leading to improved system simplicity for users while offering enhanced control for building operators. When looking at lighting in commercial buildings, and the controls that now have to accompany that lighting, it only makes sense that eventually the two would be joined at the hip. That time has come, and it is now! Lighting controls have worked their way directly into the fixtures of lighting manufacturers, and the list of available products is growing and becoming more and more economically feasible. In this article I’d like to discuss where in-fixture lighting controls make sense, and where they might not, just yet. Let’s dive in!

One of the very first applications for in- or on-fixture controls was exterior lighting, in the form of on-fixture photocells, and that application has not gone away, but rather expanded in capabilities. When fixtures are spaced far apart and require long runs of control wire, such as in the case of parking lot lighting, it makes perfect sense to put lighting control in the fixture itself, especially if dimming control is being utilized. Locating the controls inside the fixture requires the contractor to only run the power wires to the fixtures, and the rest is handled by the controls components already built in from the factory. With ever developing wireless technologies, the ability for the fixtures to then communicate to one another and be placed in groups, allows them to work as if they were centrally controlled, eliminating any sort of popcorn effect, or lights turning on one by one, that is notoriously associated with in-fixture control schemes. Added software features also provide the capability to run the in-fixture modules on either an occupancy sensor, photocell, or astronomic time schedule, or any combination of the three, for all, or any desired group of fixtures on a project site. Yet another added bonus feature of the in-fixture approach is the ability to monitor the fixture status and know exactly which fixtures are operational, and how much energy is being used with the current controls scheme. This is not possible with central area controls. This feature can allow municipalities or campuses to monitor large quantities of fixtures remotely, without the use of trucks in the field, and adjust controls schemes to maximize on energy savings. The advantages here are clear…no need to run additional control wires for existing site replacement, no need to worry about voltage drop and uneven dimming of the site and, flexibility of control through programming.

When transferring over to interior controls a lot of the same benefits we discussed above still hold true. Luminaires are delivered to the project site with the controls already built in, so the fixtures just need to be installed and programmed. This is a great solution for renovation projects where the existing fixtures may not have had the ability to dim, and dimming ability is desired for the replacement luminaires. Existing power wiring can be reused, and no new control wires are required. The new fixtures can be programmed to work in any number of group arrangements to zone spaces with desired control areas, and those zones can be rearranged, as needed, in the future without any additional rewiring. Fixtures can also be adjusted individually in order to meet light level requirements desired by individual end users. This is a perfect solution for large open offices with many occupants all wanting somewhat unique light level outputs for their work spaces. All of these features can then be placed on a building-wide network, and provide fixture-level monitoring of energy use and fixture health.

So, with all of this good there must be a catch, right? Yes, there are a few things to consider when going with an in-fixture controls solution. The first is cost. Having to add a control module for every fixture in a space is more expensive than having a single external control module for the entire space. In-fixture modules will continue to get cheaper however, and you also need to weigh that against the cost of running more wire. The second thing to take into consideration is the additional time and money required to program the modules. Having one module per fixture allows for the maximum level of flexibility when it comes to programming zones and functions, but that programming does require more time, and time is money. Having to replace a luminaire due to failure will also now require reprogramming so that fixture works with the rest of the fixtures in the space, and this will require either programming labor from a vendor or trained facility staff. Over time, this will also drop in cost as programming options will become more and more user friendly. But, for the time being, it is a significant factor to consider. Third, not all projects are fit for wireless communications, so there may be certain circumstances that will require the fixtures to maintain wired control. Many manufacturers offer a wired in-fixture controls solution using category 5 network cable or other class 2 cable to communicate between fixtures, replacing the wireless communication. This wire can be plenum rated, eliminating the need for conduit, but it is still additional wiring. Lastly, we simply are not to a point where we can place a control module in every fixture type out on the market. Decorative and compact downlight fixtures simply do not have the means to contain in-fixture controls. Luckily, some manufactures have created a way to combine in-fixture and traditional distributed controls onto a single system, so there are hybrid solutions that will allow all fixtures in the space to work in unison. With time, more and more fixtures with integrated controls will hit the market.

There you have it! In-fixture controls are moving forward, are here to stay, and will further develop over time. There are options for interior and exterior controls, and even hybrid setups that can act as one big system. Although not fit for every project and application, in-fixture controls will continue to improve and become more a viable option for many projects. As always, if you have any questions or would like more info on what MH can offer for in-fixture control solutions, feel free to reach out to, or give us a call to chat!

This article was written by Mike Bogomolov, our Controls Engineering Supervisor. Mike can be reached at 720.904.8537 or