For the fourth article in our ongoing Luminaire Level Lighting Controls (LLLCs) series, we’re looking at controls settings. At this point, we’ve talked about what an LLLC is, how to pitch LLLCs to customers and how controls can be applied in different building spaces. Now, we’ll take a deeper dive into how the control settings actually work.

Energy Trust of Oregon is focused on LLLC adoption this year and offers competitive incentives to match. Get access to the most recent incentive information at the links below:

• Instant discounts: energytrust.org/incentives/commercial-existing-buildings-lighting-instant-discounts/#incentivedetails
• Standard downstream: energytrust.org/incentives/commercial-existing-buildings-lighting-lighting-controls/#incentivedetails

What are the settings available for controls?

To set up the lighting conditions your clients want in each space, you need to know what “dials” you have. We’ll cover the five primary LLLC control strategies:

1. High-end trim (aka task tuning)
2. Occupancy/vacancy sensing
3. Daylight harvesting
4. Personal dimming
5. Scheduling

Fixtures can be grouped in overlapping zones to allow for varied controls settings within the same space. For example, a conference room could have lights grouped in two zones with segmented dimming for scene control, while the whole room might also be connected into one zone for shared occupancy and daylight settings.

Every LLLC fixture comes with a controller that allows dimming and integrated sensors for both occupancy and photo sensing. All you need to do is wire the fixture for power—setting up the controls strategies requires no additional low-voltage wire. Instead, just use an app or remote to choose your settings based on the options below:

1. High-end trim

High-end trim, also known as task tuning, sets a maximum light level below 100%. Many new LED fixtures are significantly brighter at the workplace than the fixtures they are replacing, due to LED’s directionality. By using high-end trim, you can deliver the target light level and extend the life of the fixture by reducing the operating temperature of the LEDs.

High-end trim set at 70 – 80% initially should result in ideal initial light levels, as properly specified LEDs should account for 30% lumen degradation over the life of the fixture. This is because LED light levels depreciate over time, and the end of life for an LED is defined as the point at which it reaches 70% of its initial light level. When it reaches this stage, the human eye can detect a difference in light levels. By setting high-end trim with this in mind, the luminaire can be adjusted over time so that the customer perceives no light degradation.

2. Occupancy/vacancy

LLLCs have integrated occupancy sensors on every luminaire, allowing for better sensor coverage than stand-alone sensors. LLLCs can be set up with occupancy sensing or vacancy sensing:

• Occupancy sensing (Auto On/Auto Off): The lights will turn on automatically when any single luminaire in a grouped set detects motion. The group will then stay on for the period of time you designate, and then automatically turn off.
• Vacancy sensing (Manual On/Auto Off): The lights will not turn on automatically; the user must press a switch to turn the lights on. Then, when the lights stop detecting motion, they will stay on for a set period of time before automatically turning off.

One of the most common issues with occupancy sensing is the experience of a light turning off when someone is still in the room. With LLLCs, every single fixture in a group has a sensor that needs to register no human presence for a set period before the lights will turn off—significantly decreasing the risk of unwanted shut off.

We recommend setting lights to time out after five to 10 minutes of a space being unoccupied, after which the lights could turn off or dim to a lower light level. To provide more flexibility, improved safety and a smoother transition for the occupant, many LLLC systems allow for a stepped dimming approach with a selectable fade rate. This allows you to transition to an initial dimming level after a first timeout period, and then dim to off or a lower final dimming setting after a secondary time out period.

3. Daylight harvesting

Daylight harvesting, also known as daylight dimming or daylighting, is the process of lowering electric lighting levels in response to available natural light from a window, skylight or open wall or bay door. Continuous dimming provides a smooth transition as natural light levels change through the day.

Since each luminaire has a photo sensor, they can each respond independently to daylight. It is also possible to group fixtures to respond to daylight in an aligned way—so every fixture in the group takes the “average” amount of daylight sensed and adjusts the output to be the same in response. This can support any clients who may worry about the “checkerboard” effect (different luminaires reacting differently to the exact amount of sunlight they receive).

4. Personal dimming

Personal dimming allows an individual to use a continuous dimming switch (or app) to lower the current light levels to their preference. Clients can also use dimming in scene selection, which allows you to turn on a preset combination of brightness for a set of fixtures.

Clients can either use a continuous dimmer switch, a scene selector switch or a hybrid of those two. Each LLLC fixture is equipped with a controller, allowing you to offer personal dimming and scene selection in any arrangement of fixtures that works best for your client. The capability of dimming can also be applied in coordination with occupancy settings and scheduling, as detailed below.

5. Scheduling

Scheduling gives you the option to dim or turn lighting on or off according to predetermined times of day or night. This can be a powerful strategy to layer with occupancy sensing and dimming. For example, if shutting off lights endangers safety during certain hours, lights can be scheduled to dim to the lowest safe level while in unoccupied mode and use occupancy sensing to shine a brighter “spotlight” on movement.

Similarly, you can use scheduling to turn certain lights completely off during unoccupied hours in areas where you use occupancy sensors to simply dim them to lower light levels for safety purposes during occupied hours.

Take advantage of LLLC incentives and training
By becoming an expert on controls, you’ll be able to configure lights that meet your clients’ exact needs—and deliver huge savings on their utility bills. Right now, robust incentives are being offered to help with LLLC adoption.

Look out for our next LLLC-focused article, which will focus on how to set up these control strategies via app or remote and set your customers up for success.

Energy Trust will also be hosting more sessions of our hands-on LLLC training course this year in locations across the state. Watch your email for further information!