Bi-Level Dimming (High/Low)

No confusing software interface, no massive investment, no need to worry about your Wi-Fi or internet going down, no need to “update.” Brownlee's Bi-Level Dimming control maximizes energy savings and is simpler than ever by combining an occupancy sensor, a timer, customizable three-step dimming switches (1. On: 100%; 2. Dimmed: 50%, 30%, 20% or 10% output; 3. Off) and a photo sensor to detect the amount of ambient light surrounding the fixture.

While Bi-Level Dimming (or step-dimming) is most commonly used in industrial fixtures for commercial stairwells and parking garages, Brownlee Lighting is pioneering the effort to bring the technology to the decorative market to maximize energy savings in as many areas as possible. Contact your local utility for REBATE opportunities with this control.

How It Works

When the control senses movement, it raises the fixture’s light level to 100% output and remains at full brightness as long as it senses movement. When movement is no longer detected, its internal timer begins counting. If the set period of time expires, the fixture will dim down to your selected dimming level (50%, 30%, 20% or 10% light output). Then, depending on your selected timer settings, the fixture can either remain at this dimmed level for a continuous amount of time (perfect for 24-hour burn applications such as multifamily and hotel corridors), OR, turn completely off after a set period of inactivity (great for conference rooms, offices, clubhouses, restrooms, units, etc.). Regardless of the setting, once the fixture senses movement again, it will return to full output and the process begins again. Note that BLD requires 0-10V wiring to operate.

Where is it? The control is integrally installed in the fixture (by Brownlee) beneath the diffuser. It is not visible.


Fixtures with Bi-Level Dimming can be hard-wired together in sets for simultaneous control if desired. One fixture with Bi-Level Dimming can also be hard-wired with up to two other non-BLD fixtures, so long as the non-BLD fixtures contain 0-10V dimming drivers (DIM). Note that the detection range of the BLD control is 19 feet, so be mindful of this when plotting out your plans. For example, if you have a corridor with 9 ceiling fixtures, you may be able to get away with using three fixtures with Bi-Level Dimming and six with 0-10V DIM only. Each BLD unit will then need to be hard-wired (daisy chained) to their other two respective DIM units in the field, but the non-BLD fixtures must be within 19 feet of the BLD fixture to prevent causing a dead zone with no detection. Hard-wiring a corridor retrofit may not be practical, however, so most customers simply order one BLD unit per fixture.

General Settings

The unit has a series of DIP switches that allow simple adjustment in five areas of control; Detection Range, Hold Time, Daylight Sensor, Stand-by Period and Stand-by Dimming Level.

The unit must be cycled (on/off) one time to initiate the program.


The occupancy sensor’s detection radius is approximately 19’6”, at 30 degrees to 150 degrees from the perpendicular center of the fixture, with a maximum mounting height of 19’6”. The sensor can be set to cover approximately 100%, 75%, 50%, or 10% of this area. The microwave based sensor operates at 5.8 GHz (+/- 0.75MHz). Due strictly to their mass, it is not recommended for use in lobbies with elevators. The unit ships with the factory setting at 100%.


When movement is detected, the fixture turns ON to 100% light output. It will remain at full brightness for the set “hold time,” which can be as short as 5 seconds and as long as 20 minutes. Once the hold time ends, the light is reduced to the stand-by dimming level (see “Stand-by Dimming Level” below). The unit ships with the factory setting at 90 seconds.


Once the hold time has elapsed, the “stand-by period” begins, which is the length of time that the fixture remains in its dimmed state (Stand-by Dimming Level). At the end of the set stand-by period (5 seconds up to 1 hour), the fixture will turn OFF. If you do not want the fixture to turn completely off, use the “+8” setting, which will keep the fixture in its dimmed state continuously until movement is detected again (useful in 24-hour burn applications). If you wish to bypass the step dim and have the fixture turn completely OFF at the end of hold time, use the setting “0 seconds.” The unit ships with the factory setting in the continuous dim position “+∞”.


The “daylight sensor” evaluates the amount of surrounding light in range. Measured in Lux, the sensor determines if the surrounding light in the given area meets the field configured minimum light threshold. If movement is detected and the surrounding light is below the set Lux threshold, the fixture will trigger ON and the hold time will begin. If movement is detected and the surrounding light is above the set Lux threshold, the fixture will not trigger on. The sensor can be set as low as 2Lux and as high as 100Lux. If disabled, the fixture will trigger ON when movement is detected regardless of the amount of surrounding light. The unit ships with the factory setting at DISABLE.


When the set hold time has elapsed and no further movement is detected in range, the dimming control reduces the light output to the set “stand-by dimming level,” which can be configured at 50%, 30%, 20% or 10% light output. The fixture will remain at the reduced level for the length of the stand-by period (see “Stand-by Period”), or until movement is detected, whichever comes first. The unit ships with the factory setting at 50%. *Dim percentage is an approximation of light output, it does not equate to fixture wattage draw. Contact Brownlee Lighting for wattage calculations.

Frequently Asked Questions:

Does BLD need to be combined with OCC (occupancy sensor)? No. You cannot combine ordering code BLD and OCC on the same fixture, it is not needed. If you want a traditional ON/OFF sensor – choose OCC. If you want customized options as explained above, choose BLD.

Do I need to specify DIM and BLD on the same fixture? No, Bi-Level Dimming requires 0-10V dimming to operate so DIM is automatically included when BLD is specified. However, if you plan to sync one BLD fixture to a non-BLD fixture, the non-BLD fixture must be specified with DIM.

How do I customize the settings once the fixture is installed? The control is installed within the fixture so the diffuser needs to be removed to access it. The control has set factory settings and should be customized by the contractor during installation if needed.

Can the photo sensor be disabled? Yes. Most customers disable this feature and use the control strictly for step-dimming purposes.