Application Note #489
11 Technical Support — 800.523.9466
Ambient Light Detect (ALD) – How it Works
Ambient Light Detect (ALD) is a feature that allows you to maximize the cost savings due to lighting by keeping lights
off when there is enough natural light in a space to provide adequate lighting.
Lutron’s ALD feature learns your preference as you live with the product in your space. The learning algorithm utilizes
user inputs to determine when ambient light is not enough.
Will my sensor utilize ALD?
Your sensor will utilize ALD if you’ve selected “Ambient Light Detect (ALD) Mode” while programming your unit. Some
models of Lutron’s in-wall sensors allow you to change the Auto-ON settings independently of ALD. In those models,
you must have ALD and Auto-ON / Auto-OFF (Occupancy Mode) both enabled.
How does the sensor learn my preference?
Whenever you enter a room with a Lutron in-wall sensor utilizing the ALD feature, the sensor will either turn the lights
on, or keep the lights off, based on its current light level threshold set in ALD. If you enter the room, and the lights do
not respond as you’d like, you need only to press the Tap button on your unit to turn lights on (or off, if that was your
preference) within 5 seconds of entering the room. The sensor has now learned a new light threshold for ALD. Here is
an example to illustrate the learning process:
1. You enter the room, the lights stay off, and you decide you want the lights ON...there is not enough ambient
light in the space for you.
2. You press the Tap button (within 5 seconds of entering room).
3. The unit has learned your preference for when lights should turn on, and adjusted its threshold accordingly.
If I press a button AFTER 5 seconds of being in a room, will my unit “learn” that preference?
No, you must interact within the first 5 seconds of entering the room.
How many times do I have to interact with the sensor to get it to remember my settings?
The sensor typically learns the appropriate threshold in 6-10 interactions or less.
I believe I’m using ALD correctly, but I’m still not getting the response I expect. What could be happening?
- You may have multiple users with widely different preferences. If multiple users continue to “teach” the unit separate
preferences, it will continue to try to adjust to meet the threshold, but may be stuck somewhere in between the
preferences of the two users.
- You may be trying to apply this feature to an application that is not exposed to daylight. This feature is designed to
respond to natural light. It will not necessarily respond with the same sensitivity to synthetic light sources that operate
on different wavelengths.
- You may not be able to reach your unit within 5 seconds. If your interactions do not happen within 5 seconds, you
may not be teaching the unit a new threshold, and this lack of interaction may be reinforcing the current threshold
(because it thinks you like the current setting).
To Next Page
Loading...
Need help?
General
